    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017package org.apache.commons.text;
    018
    019import java.io.IOException;
    020import java.io.Reader;
    021import java.io.Serializable;
    022import java.io.Writer;
    023import java.nio.CharBuffer;
    024import java.util.Arrays;
    025import java.util.Iterator;
    026import java.util.List;
    027import java.util.Objects;
    028
    029import org.apache.commons.lang3.ArrayUtils;
    030import org.apache.commons.lang3.StringUtils;
    031import org.apache.commons.text.matcher.StringMatcher;
    032
    033/**
    034 * Builds a string from constituent parts providing a more flexible and powerful API than {@link StringBuffer} and
    035 * {@link StringBuilder}.
    036 * <p>
    037 * The main differences from StringBuffer/StringBuilder are:
    038 * </p>
    039 * <ul>
    040 * <li>Not synchronized</li>
    041 * <li>Not final</li>
    042 * <li>Subclasses have direct access to character array</li>
    043 * <li>Additional methods
    044 * <ul>
    045 * <li>appendWithSeparators - adds an array of values, with a separator</li>
    046 * <li>appendPadding - adds a length padding characters</li>
    047 * <li>appendFixedLength - adds a fixed width field to the builder</li>
    048 * <li>toCharArray/getChars - simpler ways to get a range of the character array</li>
    049 * <li>delete - delete char or string</li>
    050 * <li>replace - search and replace for a char or string</li>
    051 * <li>leftString/rightString/midString - substring without exceptions</li>
    052 * <li>contains - whether the builder contains a char or string</li>
    053 * <li>size/clear/isEmpty - collections style API methods</li>
    054 * </ul>
    055 * </li>
    056 * <li>Views
    057 * <ul>
    058 * <li>asTokenizer - uses the internal buffer as the source of a StrTokenizer</li>
    059 * <li>asReader - uses the internal buffer as the source of a Reader</li>
    060 * <li>asWriter - allows a Writer to write directly to the internal buffer</li>
    061 * </ul>
    062 * </li>
    063 * </ul>
    064 * <p>
    065 * The aim has been to provide an API that mimics very closely what StringBuffer provides, but with additional methods.
    066 * It should be noted that some edge cases, with invalid indices or null input, have been altered - see individual
    067 * methods. The biggest of these changes is that by default, null will not output the text 'null'. This can be
    068 * controlled by a property, {@link #setNullText(String)}.
    069 * </p>
    070 * <p>
    071 * This class is called {@code TextStringBuilder} instead of {@code StringBuilder} to avoid clashing with
    072 * {@link StringBuilder}.
    073 * </p>
    074 *
    075 * @since 1.3
    076 */
    077public class TextStringBuilder implements CharSequence, Appendable, Serializable, Builder<String> {
    078
    079    /**
    080     * Inner class to allow StrBuilder to operate as a reader.
    081     */
    082    final class TextStringBuilderReader extends Reader {
    083
    084        /** The last mark position. */
    085        private int mark;
    086
    087        /** The current stream position. */
    088        private int pos;
    089
    090        /**
    091         * Default constructor.
    092         */
    093        TextStringBuilderReader() {
    094        }
    095
    096        /** {@inheritDoc} */
    097        @Override
    098        public void close() {
    099            // do nothing
    100        }
    101
    102        /** {@inheritDoc} */
    103        @Override
    104        public void mark(final int readAheadLimit) {
    105            mark = pos;
    106        }
    107
    108        /** {@inheritDoc} */
    109        @Override
    110        public boolean markSupported() {
    111            return true;
    112        }
    113
    114        /** {@inheritDoc} */
    115        @Override
    116        public int read() {
    117            if (!ready()) {
    118                return -1;
    119            }
    120            return charAt(pos++);
    121        }
    122
    123        /** {@inheritDoc} */
    124        @Override
    125        public int read(final char[] b, final int off, int len) {
    126            if (off < 0 || len < 0 || off > b.length || off + len > b.length || off + len < 0) {
    127                throw new IndexOutOfBoundsException();
    128            }
    129            if (len == 0) {
    130                return 0;
    131            }
    132            if (pos >= size()) {
    133                return -1;
    134            }
    135            if (pos + len > size()) {
    136                len = size() - pos;
    137            }
    138            TextStringBuilder.this.getChars(pos, pos + len, b, off);
    139            pos += len;
    140            return len;
    141        }
    142
    143        /** {@inheritDoc} */
    144        @Override
    145        public boolean ready() {
    146            return pos < size();
    147        }
    148
    149        /** {@inheritDoc} */
    150        @Override
    151        public void reset() {
    152            pos = mark;
    153        }
    154
    155        /** {@inheritDoc} */
    156        @Override
    157        public long skip(long n) {
    158            if (pos + n > size()) {
    159                n = size() - pos;
    160            }
    161            if (n < 0) {
    162                return 0;
    163            }
    164            pos = Math.addExact(pos, Math.toIntExact(n));
    165            return n;
    166        }
    167    }
    168
    169    /**
    170     * Inner class to allow StrBuilder to operate as a tokenizer.
    171     */
    172    final class TextStringBuilderTokenizer extends StringTokenizer {
    173
    174        /**
    175         * Default constructor.
    176         */
    177        TextStringBuilderTokenizer() {
    178        }
    179
    180        /** {@inheritDoc} */
    181        @Override
    182        public String getContent() {
    183            final String str = super.getContent();
    184            if (str == null) {
    185                return TextStringBuilder.this.toString();
    186            }
    187            return str;
    188        }
    189
    190        /** {@inheritDoc} */
    191        @Override
    192        protected List<String> tokenize(final char[] chars, final int offset, final int count) {
    193            if (chars == null) {
    194                return super.tokenize(getBuffer(), 0, TextStringBuilder.this.size());
    195            }
    196            return super.tokenize(chars, offset, count);
    197        }
    198    }
    199
    200    /**
    201     * Inner class to allow StrBuilder to operate as a writer.
    202     */
    203    final class TextStringBuilderWriter extends Writer {
    204
    205        /**
    206         * Default constructor.
    207         */
    208        TextStringBuilderWriter() {
    209        }
    210
    211        /** {@inheritDoc} */
    212        @Override
    213        public void close() {
    214            // do nothing
    215        }
    216
    217        /** {@inheritDoc} */
    218        @Override
    219        public void flush() {
    220            // do nothing
    221        }
    222
    223        /** {@inheritDoc} */
    224        @Override
    225        public void write(final char[] cbuf) {
    226            TextStringBuilder.this.append(cbuf);
    227        }
    228
    229        /** {@inheritDoc} */
    230        @Override
    231        public void write(final char[] cbuf, final int off, final int len) {
    232            TextStringBuilder.this.append(cbuf, off, len);
    233        }
    234
    235        /** {@inheritDoc} */
    236        @Override
    237        public void write(final int c) {
    238            TextStringBuilder.this.append((char) c);
    239        }
    240
    241        /** {@inheritDoc} */
    242        @Override
    243        public void write(final String str) {
    244            TextStringBuilder.this.append(str);
    245        }
    246
    247        /** {@inheritDoc} */
    248        @Override
    249        public void write(final String str, final int off, final int len) {
    250            TextStringBuilder.this.append(str, off, len);
    251        }
    252    }
    253
    254    /** The space character. */
    255    private static final char SPACE = ' ';
    256
    257    /**
    258     * The extra capacity for new builders.
    259     */
    260    static final int CAPACITY = 32;
    261
    262    /**
    263     * End-Of-Stream.
    264     */
    265    private static final int EOS = -1;
    266
    267    /**
    268     * The size of the string {@code "false"}.
    269     */
    270    private static final int FALSE_STRING_SIZE = Boolean.FALSE.toString().length();
    271
    272    /**
    273     * Required for serialization support.
    274     *
    275     * @see java.io.Serializable
    276     */
    277    private static final long serialVersionUID = 1L;
    278
    279    /**
    280     * The size of the string {@code "true"}.
    281     */
    282    private static final int TRUE_STRING_SIZE = Boolean.TRUE.toString().length();
    283
    284    /**
    285     * The maximum size buffer to allocate.
    286     *
    287     * <p>This is set to the same size used in the JDK {@link java.util.ArrayList}:</p>
    288     * <blockquote>
    289     * Some VMs reserve some header words in an array.
    290     * Attempts to allocate larger arrays may result in
    291     * OutOfMemoryError: Requested array size exceeds VM limit.
    292     * </blockquote>
    293     */
    294    private static final int MAX_BUFFER_SIZE = Integer.MAX_VALUE - 8;
    295
    296    /**
    297     * Creates a positive capacity at least as large the minimum required capacity.
    298     * If the minimum capacity is negative then this throws an OutOfMemoryError as no array
    299     * can be allocated.
    300     *
    301     * @param minCapacity the minimum capacity
    302     * @return the capacity
    303     * @throws OutOfMemoryError if the {@code minCapacity} is negative
    304     */
    305    private static int createPositiveCapacity(final int minCapacity) {
    306        if (minCapacity < 0) {
    307            // overflow
    308            throw new OutOfMemoryError("Unable to allocate array size: " + Integer.toUnsignedString(minCapacity));
    309        }
    310        // This is called when we require buffer expansion to a very big array.
    311        // Use the conservative maximum buffer size if possible, otherwise the biggest required.
    312        //
    313        // Note: In this situation JDK 1.8 java.util.ArrayList returns Integer.MAX_VALUE.
    314        // This excludes some VMs that can exceed MAX_BUFFER_SIZE but not allocate a full
    315        // Integer.MAX_VALUE length array.
    316        // The result is that we may have to allocate an array of this size more than once if
    317        // the capacity must be expanded again.
    318        return Math.max(minCapacity, MAX_BUFFER_SIZE);
    319    }
    320
    321    /**
    322     * Constructs an instance from a reference to a character array. Changes to the input chars are reflected in this
    323     * instance until the internal buffer needs to be reallocated. Using a reference to an array allows the instance to
    324     * be initialized without copying the input array.
    325     *
    326     * @param initialBuffer The initial array that will back the new builder.
    327     * @return A new instance.
    328     * @since 1.9
    329     */
    330    public static TextStringBuilder wrap(final char[] initialBuffer) {
    331        Objects.requireNonNull(initialBuffer, "initialBuffer");
    332        return new TextStringBuilder(initialBuffer, initialBuffer.length);
    333    }
    334
    335    /**
    336     * Constructs an instance from a reference to a character array. Changes to the input chars are reflected in this
    337     * instance until the internal buffer needs to be reallocated. Using a reference to an array allows the instance to
    338     * be initialized without copying the input array.
    339     *
    340     * @param initialBuffer The initial array that will back the new builder.
    341     * @param length The length of the subarray to be used; must be non-negative and no larger than
    342     *        {@code initialBuffer.length}. The new builder's size will be set to {@code length}.
    343     * @return A new instance.
    344     * @since 1.9
    345     */
    346    public static TextStringBuilder wrap(final char[] initialBuffer, final int length) {
    347        return new TextStringBuilder(initialBuffer, length);
    348    }
    349
    350    /** Internal data storage. */
    351    private char[] buffer;
    352
    353    /**
    354     * The new line, {@code null} means use the system default from {@link System#lineSeparator()}.
    355     */
    356    private String newLine;
    357
    358    /** The null text. */
    359    private String nullText;
    360
    361    /** Incremented when the buffer is reallocated. */
    362    private int reallocations;
    363
    364    /** Current size of the buffer. */
    365    private int size;
    366
    367    /**
    368     * Constructs an empty builder with an initial capacity of 32 characters.
    369     */
    370    public TextStringBuilder() {
    371        this(CAPACITY);
    372    }
    373
    374    /**
    375     * Constructs an instance from a reference to a character array.
    376     *
    377     * @param initialBuffer a reference to a character array, must not be null.
    378     * @param length The length of the subarray to be used; must be non-negative and no larger than
    379     *        {@code initialBuffer.length}. The new builder's size will be set to {@code length}.
    380     * @throws NullPointerException If {@code initialBuffer} is null.
    381     * @throws IllegalArgumentException if {@code length} is bad.
    382     */
    383    private TextStringBuilder(final char[] initialBuffer, final int length) {
    384        this.buffer = Objects.requireNonNull(initialBuffer, "initialBuffer");
    385        if (length < 0 || length > initialBuffer.length) {
    386            throw new IllegalArgumentException("initialBuffer.length=" + initialBuffer.length + ", length=" + length);
    387        }
    388        this.size = length;
    389    }
    390
    391    /**
    392     * Constructs an instance from a character sequence, allocating 32 extra characters for growth.
    393     *
    394     * @param seq the string to copy, null treated as blank string
    395     * @since 1.9
    396     */
    397    public TextStringBuilder(final CharSequence seq) {
    398        this(StringUtils.length(seq) + CAPACITY);
    399        if (seq != null) {
    400            append(seq);
    401        }
    402    }
    403
    404    /**
    405     * Constructs an instance with the specified initial capacity.
    406     *
    407     * @param initialCapacity the initial capacity, zero or less will be converted to 32
    408     */
    409    public TextStringBuilder(final int initialCapacity) {
    410        buffer = new char[initialCapacity <= 0 ? CAPACITY : initialCapacity];
    411    }
    412
    413    /**
    414     * Constructs an instance from a string, allocating 32 extra characters for growth.
    415     *
    416     * @param str the string to copy, null treated as blank string
    417     */
    418    public TextStringBuilder(final String str) {
    419        this(StringUtils.length(str) + CAPACITY);
    420        if (str != null) {
    421            append(str);
    422        }
    423    }
    424
    425    /**
    426     * Appends a boolean value to the string builder.
    427     *
    428     * @param value the value to append
    429     * @return this, to enable chaining
    430     */
    431    public TextStringBuilder append(final boolean value) {
    432        if (value) {
    433            ensureCapacityInternal(size + TRUE_STRING_SIZE);
    434            appendTrue(size);
    435        } else {
    436            ensureCapacityInternal(size + FALSE_STRING_SIZE);
    437            appendFalse(size);
    438        }
    439        return this;
    440    }
    441
    442    /**
    443     * Appends a char value to the string builder.
    444     *
    445     * @param ch the value to append
    446     * @return this, to enable chaining
    447     */
    448    @Override
    449    public TextStringBuilder append(final char ch) {
    450        final int len = length();
    451        ensureCapacityInternal(len + 1);
    452        buffer[size++] = ch;
    453        return this;
    454    }
    455
    456    /**
    457     * Appends a char array to the string builder. Appending null will call {@link #appendNull()}.
    458     *
    459     * @param chars the char array to append
    460     * @return this, to enable chaining
    461     */
    462    public TextStringBuilder append(final char[] chars) {
    463        if (chars == null) {
    464            return appendNull();
    465        }
    466        final int strLen = chars.length;
    467        if (strLen > 0) {
    468            final int len = length();
    469            ensureCapacityInternal(len + strLen);
    470            System.arraycopy(chars, 0, buffer, len, strLen);
    471            size += strLen;
    472        }
    473        return this;
    474    }
    475
    476    /**
    477     * Appends a char array to the string builder. Appending null will call {@link #appendNull()}.
    478     *
    479     * @param chars the char array to append
    480     * @param startIndex the start index, inclusive, must be valid
    481     * @param length the length to append, must be valid
    482     * @return this, to enable chaining
    483     * @throws StringIndexOutOfBoundsException if {@code startIndex} is not in the
    484     *  range {@code 0 <= startIndex <= chars.length}
    485     * @throws StringIndexOutOfBoundsException if {@code length < 0}
    486     * @throws StringIndexOutOfBoundsException if {@code startIndex + length > chars.length}
    487     */
    488    public TextStringBuilder append(final char[] chars, final int startIndex, final int length) {
    489        if (chars == null) {
    490            return appendNull();
    491        }
    492        if (startIndex < 0 || startIndex > chars.length) {
    493            throw new StringIndexOutOfBoundsException("Invalid startIndex: " + length);
    494        }
    495        if (length < 0 || startIndex + length > chars.length) {
    496            throw new StringIndexOutOfBoundsException("Invalid length: " + length);
    497        }
    498        if (length > 0) {
    499            final int len = length();
    500            ensureCapacityInternal(len + length);
    501            System.arraycopy(chars, startIndex, buffer, len, length);
    502            size += length;
    503        }
    504        return this;
    505    }
    506
    507    /**
    508     * Appends the contents of a char buffer to this string builder. Appending null will call {@link #appendNull()}.
    509     *
    510     * @param str the char buffer to append
    511     * @return this, to enable chaining
    512     */
    513    public TextStringBuilder append(final CharBuffer str) {
    514        return append(str, 0, StringUtils.length(str));
    515    }
    516
    517    /**
    518     * Appends the contents of a char buffer to this string builder. Appending null will call {@link #appendNull()}.
    519     *
    520     * @param buf the char buffer to append
    521     * @param startIndex the start index, inclusive, must be valid
    522     * @param length the length to append, must be valid
    523     * @return this, to enable chaining
    524     */
    525    public TextStringBuilder append(final CharBuffer buf, final int startIndex, final int length) {
    526        if (buf == null) {
    527            return appendNull();
    528        }
    529        if (buf.hasArray()) {
    530            final int totalLength = buf.remaining();
    531            if (startIndex < 0 || startIndex > totalLength) {
    532                throw new StringIndexOutOfBoundsException("startIndex must be valid");
    533            }
    534            if (length < 0 || startIndex + length > totalLength) {
    535                throw new StringIndexOutOfBoundsException("length must be valid");
    536            }
    537            final int len = length();
    538            ensureCapacityInternal(len + length);
    539            System.arraycopy(buf.array(), buf.arrayOffset() + buf.position() + startIndex, buffer, len, length);
    540            size += length;
    541        } else {
    542            append(buf.toString(), startIndex, length);
    543        }
    544        return this;
    545    }
    546
    547    /**
    548     * Appends a CharSequence to this string builder. Appending null will call {@link #appendNull()}.
    549     *
    550     * @param seq the CharSequence to append
    551     * @return this, to enable chaining
    552     */
    553    @Override
    554    public TextStringBuilder append(final CharSequence seq) {
    555        if (seq == null) {
    556            return appendNull();
    557        }
    558        if (seq instanceof TextStringBuilder) {
    559            return append((TextStringBuilder) seq);
    560        }
    561        if (seq instanceof StringBuilder) {
    562            return append((StringBuilder) seq);
    563        }
    564        if (seq instanceof StringBuffer) {
    565            return append((StringBuffer) seq);
    566        }
    567        if (seq instanceof CharBuffer) {
    568            return append((CharBuffer) seq);
    569        }
    570        return append(seq.toString());
    571    }
    572
    573    /**
    574     * Appends part of a CharSequence to this string builder. Appending null will call {@link #appendNull()}.
    575     *
    576     * @param seq the CharSequence to append
    577     * @param startIndex the start index, inclusive, must be valid
    578     * @param endIndex the end index, exclusive, must be valid
    579     * @return this, to enable chaining
    580     */
    581    @Override
    582    public TextStringBuilder append(final CharSequence seq, final int startIndex, final int endIndex) {
    583        if (seq == null) {
    584            return appendNull();
    585        }
    586        if (endIndex <= 0) {
    587            throw new StringIndexOutOfBoundsException("endIndex must be valid");
    588        }
    589        if (startIndex >= endIndex) {
    590            throw new StringIndexOutOfBoundsException("endIndex must be greater than startIndex");
    591        }
    592        return append(seq.toString(), startIndex, endIndex - startIndex);
    593    }
    594
    595    /**
    596     * Appends a double value to the string builder using {@code String.valueOf}.
    597     *
    598     * @param value the value to append
    599     * @return this, to enable chaining
    600     */
    601    public TextStringBuilder append(final double value) {
    602        return append(String.valueOf(value));
    603    }
    604
    605    /**
    606     * Appends a float value to the string builder using {@code String.valueOf}.
    607     *
    608     * @param value the value to append
    609     * @return this, to enable chaining
    610     */
    611    public TextStringBuilder append(final float value) {
    612        return append(String.valueOf(value));
    613    }
    614
    615    /**
    616     * Appends an int value to the string builder using {@code String.valueOf}.
    617     *
    618     * @param value the value to append
    619     * @return this, to enable chaining
    620     */
    621    public TextStringBuilder append(final int value) {
    622        return append(String.valueOf(value));
    623    }
    624
    625    /**
    626     * Appends a long value to the string builder using {@code String.valueOf}.
    627     *
    628     * @param value the value to append
    629     * @return this, to enable chaining
    630     */
    631    public TextStringBuilder append(final long value) {
    632        return append(String.valueOf(value));
    633    }
    634
    635    /**
    636     * Appends an object to this string builder. Appending null will call {@link #appendNull()}.
    637     *
    638     * @param obj the object to append
    639     * @return this, to enable chaining
    640     */
    641    public TextStringBuilder append(final Object obj) {
    642        if (obj == null) {
    643            return appendNull();
    644        }
    645        if (obj instanceof CharSequence) {
    646            return append((CharSequence) obj);
    647        }
    648        return append(obj.toString());
    649    }
    650
    651    /**
    652     * Appends a string to this string builder. Appending null will call {@link #appendNull()}.
    653     *
    654     * @param str the string to append
    655     * @return this, to enable chaining
    656     */
    657    public TextStringBuilder append(final String str) {
    658        return append(str, 0, StringUtils.length(str));
    659    }
    660
    661    /**
    662     * Appends part of a string to this string builder. Appending null will call {@link #appendNull()}.
    663     *
    664     * @param str the string to append
    665     * @param startIndex the start index, inclusive, must be valid
    666     * @param length the length to append, must be valid
    667     * @return this, to enable chaining
    668     * @throws StringIndexOutOfBoundsException if {@code startIndex} is not in the
    669     *  range {@code 0 <= startIndex <= str.length()}
    670     * @throws StringIndexOutOfBoundsException if {@code length < 0}
    671     * @throws StringIndexOutOfBoundsException if {@code startIndex + length > str.length()}
    672     */
    673    public TextStringBuilder append(final String str, final int startIndex, final int length) {
    674        if (str == null) {
    675            return appendNull();
    676        }
    677        if (startIndex < 0 || startIndex > str.length()) {
    678            throw new StringIndexOutOfBoundsException("startIndex must be valid");
    679        }
    680        if (length < 0 || startIndex + length > str.length()) {
    681            throw new StringIndexOutOfBoundsException("length must be valid");
    682        }
    683        if (length > 0) {
    684            final int len = length();
    685            ensureCapacityInternal(len + length);
    686            str.getChars(startIndex, startIndex + length, buffer, len);
    687            size += length;
    688        }
    689        return this;
    690    }
    691
    692    /**
    693     * Calls {@link String#format(String, Object...)} and appends the result.
    694     *
    695     * @param format the format string
    696     * @param objs the objects to use in the format string
    697     * @return {@code this} to enable chaining
    698     * @see String#format(String, Object...)
    699     */
    700    public TextStringBuilder append(final String format, final Object... objs) {
    701        return append(String.format(format, objs));
    702    }
    703
    704    /**
    705     * Appends a string buffer to this string builder. Appending null will call {@link #appendNull()}.
    706     *
    707     * @param str the string buffer to append
    708     * @return this, to enable chaining
    709     */
    710    public TextStringBuilder append(final StringBuffer str) {
    711        return append(str, 0, StringUtils.length(str));
    712    }
    713
    714    /**
    715     * Appends part of a string buffer to this string builder. Appending null will call {@link #appendNull()}.
    716     *
    717     * @param str the string to append
    718     * @param startIndex the start index, inclusive, must be valid
    719     * @param length the length to append, must be valid
    720     * @return this, to enable chaining
    721     */
    722    public TextStringBuilder append(final StringBuffer str, final int startIndex, final int length) {
    723        if (str == null) {
    724            return appendNull();
    725        }
    726        if (startIndex < 0 || startIndex > str.length()) {
    727            throw new StringIndexOutOfBoundsException("startIndex must be valid");
    728        }
    729        if (length < 0 || startIndex + length > str.length()) {
    730            throw new StringIndexOutOfBoundsException("length must be valid");
    731        }
    732        if (length > 0) {
    733            final int len = length();
    734            ensureCapacityInternal(len + length);
    735            str.getChars(startIndex, startIndex + length, buffer, len);
    736            size += length;
    737        }
    738        return this;
    739    }
    740
    741    /**
    742     * Appends a StringBuilder to this string builder. Appending null will call {@link #appendNull()}.
    743     *
    744     * @param str the StringBuilder to append
    745     * @return this, to enable chaining
    746     */
    747    public TextStringBuilder append(final StringBuilder str) {
    748        return append(str, 0, StringUtils.length(str));
    749    }
    750
    751    /**
    752     * Appends part of a StringBuilder to this string builder. Appending null will call {@link #appendNull()}.
    753     *
    754     * @param str the StringBuilder to append
    755     * @param startIndex the start index, inclusive, must be valid
    756     * @param length the length to append, must be valid
    757     * @return this, to enable chaining
    758     */
    759    public TextStringBuilder append(final StringBuilder str, final int startIndex, final int length) {
    760        if (str == null) {
    761            return appendNull();
    762        }
    763        if (startIndex < 0 || startIndex > str.length()) {
    764            throw new StringIndexOutOfBoundsException("startIndex must be valid");
    765        }
    766        if (length < 0 || startIndex + length > str.length()) {
    767            throw new StringIndexOutOfBoundsException("length must be valid");
    768        }
    769        if (length > 0) {
    770            final int len = length();
    771            ensureCapacityInternal(len + length);
    772            str.getChars(startIndex, startIndex + length, buffer, len);
    773            size += length;
    774        }
    775        return this;
    776    }
    777
    778    /**
    779     * Appends another string builder to this string builder. Appending null will call {@link #appendNull()}.
    780     *
    781     * @param str the string builder to append
    782     * @return this, to enable chaining
    783     */
    784    public TextStringBuilder append(final TextStringBuilder str) {
    785        return append(str, 0, StringUtils.length(str));
    786    }
    787
    788    /**
    789     * Appends part of a string builder to this string builder. Appending null will call {@link #appendNull()}.
    790     *
    791     * @param str the string to append
    792     * @param startIndex the start index, inclusive, must be valid
    793     * @param length the length to append, must be valid
    794     * @return this, to enable chaining
    795     */
    796    public TextStringBuilder append(final TextStringBuilder str, final int startIndex, final int length) {
    797        if (str == null) {
    798            return appendNull();
    799        }
    800        if (startIndex < 0 || startIndex > str.length()) {
    801            throw new StringIndexOutOfBoundsException("startIndex must be valid");
    802        }
    803        if (length < 0 || startIndex + length > str.length()) {
    804            throw new StringIndexOutOfBoundsException("length must be valid");
    805        }
    806        if (length > 0) {
    807            final int len = length();
    808            ensureCapacityInternal(len + length);
    809            str.getChars(startIndex, startIndex + length, buffer, len);
    810            size += length;
    811        }
    812        return this;
    813    }
    814
    815    /**
    816     * Appends each item in an iterable to the builder without any separators. Appending a null iterable will have no
    817     * effect. Each object is appended using {@link #append(Object)}.
    818     *
    819     * @param iterable the iterable to append
    820     * @return this, to enable chaining
    821     */
    822    public TextStringBuilder appendAll(final Iterable<?> iterable) {
    823        if (iterable != null) {
    824            iterable.forEach(this::append);
    825        }
    826        return this;
    827    }
    828
    829    /**
    830     * Appends each item in an iterator to the builder without any separators. Appending a null iterator will have no
    831     * effect. Each object is appended using {@link #append(Object)}.
    832     *
    833     * @param it the iterator to append
    834     * @return this, to enable chaining
    835     */
    836    public TextStringBuilder appendAll(final Iterator<?> it) {
    837        if (it != null) {
    838            it.forEachRemaining(this::append);
    839        }
    840        return this;
    841    }
    842
    843    /**
    844     * Appends each item in an array to the builder without any separators. Appending a null array will have no effect.
    845     * Each object is appended using {@link #append(Object)}.
    846     *
    847     * @param <T> the element type
    848     * @param array the array to append
    849     * @return this, to enable chaining
    850     */
    851    public <T> TextStringBuilder appendAll(@SuppressWarnings("unchecked") final T... array) {
    852        /*
    853         * @SuppressWarnings used to hide warning about vararg usage. We cannot use @SafeVarargs, since this method is
    854         * not final. Using @SuppressWarnings is fine, because it isn't inherited by subclasses, so each subclass must
    855         * vouch for itself whether its use of 'array' is safe.
    856         */
    857        if (array != null && array.length > 0) {
    858            for (final Object element : array) {
    859                append(element);
    860            }
    861        }
    862        return this;
    863    }
    864
    865    /** Appends {@code "false"}. */
    866    private void appendFalse(int index) {
    867        buffer[index++] = 'f';
    868        buffer[index++] = 'a';
    869        buffer[index++] = 'l';
    870        buffer[index++] = 's';
    871        buffer[index] = 'e';
    872        size += FALSE_STRING_SIZE;
    873    }
    874
    875    /**
    876     * Appends an object to the builder padding on the left to a fixed width. The {@code String.valueOf} of the
    877     * {@code int} value is used. If the formatted value is larger than the length, the left hand side is lost.
    878     *
    879     * @param value the value to append
    880     * @param width the fixed field width, zero or negative has no effect
    881     * @param padChar the pad character to use
    882     * @return this, to enable chaining
    883     */
    884    public TextStringBuilder appendFixedWidthPadLeft(final int value, final int width, final char padChar) {
    885        return appendFixedWidthPadLeft(String.valueOf(value), width, padChar);
    886    }
    887
    888    /**
    889     * Appends an object to the builder padding on the left to a fixed width. The {@code toString} of the object is
    890     * used. If the object is larger than the length, the left hand side is lost. If the object is null, the null text
    891     * value is used.
    892     *
    893     * @param obj the object to append, null uses null text
    894     * @param width the fixed field width, zero or negative has no effect
    895     * @param padChar the pad character to use
    896     * @return this, to enable chaining
    897     */
    898    public TextStringBuilder appendFixedWidthPadLeft(final Object obj, final int width, final char padChar) {
    899        if (width > 0) {
    900            ensureCapacityInternal(size + width);
    901            String str = Objects.toString(obj, getNullText());
    902            if (str == null) {
    903                str = StringUtils.EMPTY;
    904            }
    905            final int strLen = str.length();
    906            if (strLen >= width) {
    907                str.getChars(strLen - width, strLen, buffer, size);
    908            } else {
    909                final int padLen = width - strLen;
    910                final int toIndex = size + padLen;
    911                Arrays.fill(buffer, size, toIndex, padChar);
    912                str.getChars(0, strLen, buffer, toIndex);
    913            }
    914            size += width;
    915        }
    916        return this;
    917    }
    918
    919    /**
    920     * Appends an object to the builder padding on the right to a fixed length. The {@code String.valueOf} of the
    921     * {@code int} value is used. If the object is larger than the length, the right hand side is lost.
    922     *
    923     * @param value the value to append
    924     * @param width the fixed field width, zero or negative has no effect
    925     * @param padChar the pad character to use
    926     * @return this, to enable chaining
    927     */
    928    public TextStringBuilder appendFixedWidthPadRight(final int value, final int width, final char padChar) {
    929        return appendFixedWidthPadRight(String.valueOf(value), width, padChar);
    930    }
    931
    932    /**
    933     * Appends an object to the builder padding on the right to a fixed length. The {@code toString} of the object is
    934     * used. If the object is larger than the length, the right hand side is lost. If the object is null, null text
    935     * value is used.
    936     *
    937     * @param obj the object to append, null uses null text
    938     * @param width the fixed field width, zero or negative has no effect
    939     * @param padChar the pad character to use
    940     * @return this, to enable chaining
    941     */
    942    public TextStringBuilder appendFixedWidthPadRight(final Object obj, final int width, final char padChar) {
    943        if (width > 0) {
    944            ensureCapacityInternal(size + width);
    945            String str = Objects.toString(obj, getNullText());
    946            if (str == null) {
    947                str = StringUtils.EMPTY;
    948            }
    949            final int strLen = str.length();
    950            if (strLen >= width) {
    951                str.getChars(0, width, buffer, size);
    952            } else {
    953                str.getChars(0, strLen, buffer, size);
    954                final int fromIndex = size + strLen;
    955                Arrays.fill(buffer, fromIndex, fromIndex + width - strLen, padChar);
    956            }
    957            size += width;
    958        }
    959        return this;
    960    }
    961
    962    /**
    963     * Appends a boolean value followed by a new line to the string builder.
    964     *
    965     * @param value the value to append
    966     * @return this, to enable chaining
    967     */
    968    public TextStringBuilder appendln(final boolean value) {
    969        return append(value).appendNewLine();
    970    }
    971
    972    /**
    973     * Appends a char value followed by a new line to the string builder.
    974     *
    975     * @param ch the value to append
    976     * @return this, to enable chaining
    977     */
    978    public TextStringBuilder appendln(final char ch) {
    979        return append(ch).appendNewLine();
    980    }
    981
    982    /**
    983     * Appends a char array followed by a new line to the string builder. Appending null will call
    984     * {@link #appendNull()}.
    985     *
    986     * @param chars the char array to append
    987     * @return this, to enable chaining
    988     */
    989    public TextStringBuilder appendln(final char[] chars) {
    990        return append(chars).appendNewLine();
    991    }
    992
    993    /**
    994     * Appends a char array followed by a new line to the string builder. Appending null will call
    995     * {@link #appendNull()}.
    996     *
    997     * @param chars the char array to append
    998     * @param startIndex the start index, inclusive, must be valid
    999     * @param length the length to append, must be valid
    1000     * @return this, to enable chaining
    1001     */
    1002    public TextStringBuilder appendln(final char[] chars, final int startIndex, final int length) {
    1003        return append(chars, startIndex, length).appendNewLine();
    1004    }
    1005
    1006    /**
    1007     * Appends a double value followed by a new line to the string builder using {@code String.valueOf}.
    1008     *
    1009     * @param value the value to append
    1010     * @return this, to enable chaining
    1011     */
    1012    public TextStringBuilder appendln(final double value) {
    1013        return append(value).appendNewLine();
    1014    }
    1015
    1016    /**
    1017     * Appends a float value followed by a new line to the string builder using {@code String.valueOf}.
    1018     *
    1019     * @param value the value to append
    1020     * @return this, to enable chaining
    1021     */
    1022    public TextStringBuilder appendln(final float value) {
    1023        return append(value).appendNewLine();
    1024    }
    1025
    1026    /**
    1027     * Appends an int value followed by a new line to the string builder using {@code String.valueOf}.
    1028     *
    1029     * @param value the value to append
    1030     * @return this, to enable chaining
    1031     */
    1032    public TextStringBuilder appendln(final int value) {
    1033        return append(value).appendNewLine();
    1034    }
    1035
    1036    /**
    1037     * Appends a long value followed by a new line to the string builder using {@code String.valueOf}.
    1038     *
    1039     * @param value the value to append
    1040     * @return this, to enable chaining
    1041     */
    1042    public TextStringBuilder appendln(final long value) {
    1043        return append(value).appendNewLine();
    1044    }
    1045
    1046    /**
    1047     * Appends an object followed by a new line to this string builder. Appending null will call {@link #appendNull()}.
    1048     *
    1049     * @param obj the object to append
    1050     * @return this, to enable chaining
    1051     */
    1052    public TextStringBuilder appendln(final Object obj) {
    1053        return append(obj).appendNewLine();
    1054    }
    1055
    1056    /**
    1057     * Appends a string followed by a new line to this string builder. Appending null will call {@link #appendNull()}.
    1058     *
    1059     * @param str the string to append
    1060     * @return this, to enable chaining
    1061     */
    1062    public TextStringBuilder appendln(final String str) {
    1063        return append(str).appendNewLine();
    1064    }
    1065
    1066    /**
    1067     * Appends part of a string followed by a new line to this string builder. Appending null will call
    1068     * {@link #appendNull()}.
    1069     *
    1070     * @param str the string to append
    1071     * @param startIndex the start index, inclusive, must be valid
    1072     * @param length the length to append, must be valid
    1073     * @return this, to enable chaining
    1074     */
    1075    public TextStringBuilder appendln(final String str, final int startIndex, final int length) {
    1076        return append(str, startIndex, length).appendNewLine();
    1077    }
    1078
    1079    /**
    1080     * Calls {@link String#format(String, Object...)} and appends the result.
    1081     *
    1082     * @param format the format string
    1083     * @param objs the objects to use in the format string
    1084     * @return {@code this} to enable chaining
    1085     * @see String#format(String, Object...)
    1086     */
    1087    public TextStringBuilder appendln(final String format, final Object... objs) {
    1088        return append(format, objs).appendNewLine();
    1089    }
    1090
    1091    /**
    1092     * Appends a string buffer followed by a new line to this string builder. Appending null will call
    1093     * {@link #appendNull()}.
    1094     *
    1095     * @param str the string buffer to append
    1096     * @return this, to enable chaining
    1097     */
    1098    public TextStringBuilder appendln(final StringBuffer str) {
    1099        return append(str).appendNewLine();
    1100    }
    1101
    1102    /**
    1103     * Appends part of a string buffer followed by a new line to this string builder. Appending null will call
    1104     * {@link #appendNull()}.
    1105     *
    1106     * @param str the string to append
    1107     * @param startIndex the start index, inclusive, must be valid
    1108     * @param length the length to append, must be valid
    1109     * @return this, to enable chaining
    1110     */
    1111    public TextStringBuilder appendln(final StringBuffer str, final int startIndex, final int length) {
    1112        return append(str, startIndex, length).appendNewLine();
    1113    }
    1114
    1115    /**
    1116     * Appends a string builder followed by a new line to this string builder. Appending null will call
    1117     * {@link #appendNull()}.
    1118     *
    1119     * @param str the string builder to append
    1120     * @return this, to enable chaining
    1121     */
    1122    public TextStringBuilder appendln(final StringBuilder str) {
    1123        return append(str).appendNewLine();
    1124    }
    1125
    1126    /**
    1127     * Appends part of a string builder followed by a new line to this string builder. Appending null will call
    1128     * {@link #appendNull()}.
    1129     *
    1130     * @param str the string builder to append
    1131     * @param startIndex the start index, inclusive, must be valid
    1132     * @param length the length to append, must be valid
    1133     * @return this, to enable chaining
    1134     */
    1135    public TextStringBuilder appendln(final StringBuilder str, final int startIndex, final int length) {
    1136        return append(str, startIndex, length).appendNewLine();
    1137    }
    1138
    1139    /**
    1140     * Appends another string builder followed by a new line to this string builder. Appending null will call
    1141     * {@link #appendNull()}.
    1142     *
    1143     * @param str the string builder to append
    1144     * @return this, to enable chaining
    1145     */
    1146    public TextStringBuilder appendln(final TextStringBuilder str) {
    1147        return append(str).appendNewLine();
    1148    }
    1149
    1150    /**
    1151     * Appends part of a string builder followed by a new line to this string builder. Appending null will call
    1152     * {@link #appendNull()}.
    1153     *
    1154     * @param str the string to append
    1155     * @param startIndex the start index, inclusive, must be valid
    1156     * @param length the length to append, must be valid
    1157     * @return this, to enable chaining
    1158     */
    1159    public TextStringBuilder appendln(final TextStringBuilder str, final int startIndex, final int length) {
    1160        return append(str, startIndex, length).appendNewLine();
    1161    }
    1162
    1163    /**
    1164     * Appends this builder's new line string to this builder.
    1165     * <p>
    1166     * By default, the new line is the system default from {@link System#lineSeparator()}.
    1167     * </p>
    1168     * <p>
    1169     * The new line string can be changed using {@link #setNewLineText(String)}. For example, you can use this to force the output to always use Unix line
    1170     * endings even when on Windows.
    1171     * </p>
    1172     *
    1173     * @return this
    1174     * @see #getNewLineText()
    1175     * @see #setNewLineText(String)
    1176     */
    1177    public TextStringBuilder appendNewLine() {
    1178        if (newLine == null) {
    1179            append(System.lineSeparator());
    1180            return this;
    1181        }
    1182        return append(newLine);
    1183    }
    1184
    1185    /**
    1186     * Appends the text representing {@code null} to this string builder.
    1187     *
    1188     * @return this, to enable chaining
    1189     */
    1190    public TextStringBuilder appendNull() {
    1191        if (nullText == null) {
    1192            return this;
    1193        }
    1194        return append(nullText);
    1195    }
    1196
    1197    /**
    1198     * Appends the pad character to the builder the specified number of times.
    1199     *
    1200     * @param length the length to append, negative means no append
    1201     * @param padChar the character to append
    1202     * @return this, to enable chaining
    1203     */
    1204    public TextStringBuilder appendPadding(final int length, final char padChar) {
    1205        if (length >= 0) {
    1206            ensureCapacityInternal(size + length);
    1207            for (int i = 0; i < length; i++) {
    1208                buffer[size++] = padChar;
    1209            }
    1210        }
    1211        return this;
    1212    }
    1213
    1214    /**
    1215     * Appends a separator if the builder is currently non-empty. The separator is appended using {@link #append(char)}.
    1216     * <p>
    1217     * This method is useful for adding a separator each time around the loop except the first.
    1218     * </p>
    1219     *
    1220     * <pre>
    1221     * for (Iterator it = list.iterator(); it.hasNext();) {
    1222     *     appendSeparator(',');
    1223     *     append(it.next());
    1224     * }
    1225     * </pre>
    1226     *
    1227     * <p>
    1228     * Note that for this simple example, you should use {@link #appendWithSeparators(Iterable, String)}.
    1229     * </p>
    1230     *
    1231     * @param separator the separator to use
    1232     * @return this, to enable chaining
    1233     */
    1234    public TextStringBuilder appendSeparator(final char separator) {
    1235        if (isNotEmpty()) {
    1236            append(separator);
    1237        }
    1238        return this;
    1239    }
    1240
    1241    /**
    1242     * Appends one of both separators to the builder If the builder is currently empty it will append the
    1243     * defaultIfEmpty-separator Otherwise it will append the standard-separator
    1244     *
    1245     * The separator is appended using {@link #append(char)}.
    1246     *
    1247     * @param standard the separator if builder is not empty
    1248     * @param defaultIfEmpty the separator if builder is empty
    1249     * @return this, to enable chaining
    1250     */
    1251    public TextStringBuilder appendSeparator(final char standard, final char defaultIfEmpty) {
    1252        if (isEmpty()) {
    1253            append(defaultIfEmpty);
    1254        } else {
    1255            append(standard);
    1256        }
    1257        return this;
    1258    }
    1259
    1260    /**
    1261     * Appends a separator to the builder if the loop index is greater than zero. The separator is appended using
    1262     * {@link #append(char)}.
    1263     * <p>
    1264     * This method is useful for adding a separator each time around the loop except the first.
    1265     * </p>
    1266     *
    1267     * <pre>
    1268     * for (int i = 0; i &lt; list.size(); i++) {
    1269     *     appendSeparator(",", i);
    1270     *     append(list.get(i));
    1271     * }
    1272     * </pre>
    1273     *
    1274     * <p>
    1275     * Note that for this simple example, you should use {@link #appendWithSeparators(Iterable, String)}.
    1276     * </p>
    1277     *
    1278     * @param separator the separator to use
    1279     * @param loopIndex the loop index
    1280     * @return this, to enable chaining
    1281     */
    1282    public TextStringBuilder appendSeparator(final char separator, final int loopIndex) {
    1283        if (loopIndex > 0) {
    1284            append(separator);
    1285        }
    1286        return this;
    1287    }
    1288
    1289    /**
    1290     * Appends a separator if the builder is currently non-empty. Appending a null separator will have no effect. The
    1291     * separator is appended using {@link #append(String)}.
    1292     * <p>
    1293     * This method is useful for adding a separator each time around the loop except the first.
    1294     * </p>
    1295     *
    1296     * <pre>
    1297     * for (Iterator it = list.iterator(); it.hasNext();) {
    1298     *     appendSeparator(",");
    1299     *     append(it.next());
    1300     * }
    1301     * </pre>
    1302     *
    1303     * <p>
    1304     * Note that for this simple example, you should use {@link #appendWithSeparators(Iterable, String)}.
    1305     * </p>
    1306     *
    1307     * @param separator the separator to use, null means no separator
    1308     * @return this, to enable chaining
    1309     */
    1310    public TextStringBuilder appendSeparator(final String separator) {
    1311        return appendSeparator(separator, null);
    1312    }
    1313
    1314    /**
    1315     * Appends a separator to the builder if the loop index is greater than zero. Appending a null separator will have
    1316     * no effect. The separator is appended using {@link #append(String)}.
    1317     * <p>
    1318     * This method is useful for adding a separator each time around the loop except the first.
    1319     * </p>
    1320     *
    1321     * <pre>
    1322     * for (int i = 0; i &lt; list.size(); i++) {
    1323     *     appendSeparator(",", i);
    1324     *     append(list.get(i));
    1325     * }
    1326     * </pre>
    1327     *
    1328     * <p>
    1329     * Note that for this simple example, you should use {@link #appendWithSeparators(Iterable, String)}.
    1330     * </p>
    1331     *
    1332     * @param separator the separator to use, null means no separator
    1333     * @param loopIndex the loop index
    1334     * @return this, to enable chaining
    1335     */
    1336    public TextStringBuilder appendSeparator(final String separator, final int loopIndex) {
    1337        if (separator != null && loopIndex > 0) {
    1338            append(separator);
    1339        }
    1340        return this;
    1341    }
    1342
    1343    /**
    1344     * Appends one of both separators to the StrBuilder. If the builder is currently empty, it will append the
    1345     * defaultIfEmpty-separator, otherwise it will append the standard-separator.
    1346     * <p>
    1347     * Appending a null separator will have no effect. The separator is appended using {@link #append(String)}.
    1348     * </p>
    1349     * <p>
    1350     * This method is for example useful for constructing queries
    1351     * </p>
    1352     *
    1353     * <pre>
    1354     * StrBuilder whereClause = new StrBuilder();
    1355     * if (searchCommand.getPriority() != null) {
    1356     *  whereClause.appendSeparator(" and", " where");
    1357     *  whereClause.append(" priority = ?")
    1358     * }
    1359     * if (searchCommand.getComponent() != null) {
    1360     *  whereClause.appendSeparator(" and", " where");
    1361     *  whereClause.append(" component = ?")
    1362     * }
    1363     * selectClause.append(whereClause)
    1364     * </pre>
    1365     *
    1366     * @param standard the separator if builder is not empty, null means no separator
    1367     * @param defaultIfEmpty the separator if builder is empty, null means no separator
    1368     * @return this, to enable chaining
    1369     */
    1370    public TextStringBuilder appendSeparator(final String standard, final String defaultIfEmpty) {
    1371        final String str = isEmpty() ? defaultIfEmpty : standard;
    1372        if (str != null) {
    1373            append(str);
    1374        }
    1375        return this;
    1376    }
    1377
    1378    /**
    1379     * Appends current contents of this {@code StrBuilder} to the provided {@link Appendable}.
    1380     * <p>
    1381     * This method tries to avoid doing any extra copies of contents.
    1382     * </p>
    1383     *
    1384     * @param appendable the appendable to append data to
    1385     * @throws IOException if an I/O error occurs.
    1386     * @see #readFrom(Readable)
    1387     */
    1388    public void appendTo(final Appendable appendable) throws IOException {
    1389        if (appendable instanceof Writer) {
    1390            ((Writer) appendable).write(buffer, 0, size);
    1391        } else if (appendable instanceof StringBuilder) {
    1392            ((StringBuilder) appendable).append(buffer, 0, size);
    1393        } else if (appendable instanceof StringBuffer) {
    1394            ((StringBuffer) appendable).append(buffer, 0, size);
    1395        } else if (appendable instanceof CharBuffer) {
    1396            ((CharBuffer) appendable).put(buffer, 0, size);
    1397        } else {
    1398            appendable.append(this);
    1399        }
    1400    }
    1401
    1402    /** Appends {@code "true"}. */
    1403    private void appendTrue(int index) {
    1404        buffer[index++] = 't';
    1405        buffer[index++] = 'r';
    1406        buffer[index++] = 'u';
    1407        buffer[index] = 'e';
    1408        size += TRUE_STRING_SIZE;
    1409    }
    1410
    1411    /**
    1412     * Appends an iterable placing separators between each value, but not before the first or after the last. Appending
    1413     * a null iterable will have no effect. Each object is appended using {@link #append(Object)}.
    1414     *
    1415     * @param iterable the iterable to append
    1416     * @param separator the separator to use, null means no separator
    1417     * @return this, to enable chaining
    1418     */
    1419    public TextStringBuilder appendWithSeparators(final Iterable<?> iterable, final String separator) {
    1420        if (iterable != null) {
    1421            appendWithSeparators(iterable.iterator(), separator);
    1422        }
    1423        return this;
    1424    }
    1425
    1426    /**
    1427     * Appends an iterator placing separators between each value, but not before the first or after the last. Appending
    1428     * a null iterator will have no effect. Each object is appended using {@link #append(Object)}.
    1429     *
    1430     * @param it the iterator to append
    1431     * @param separator the separator to use, null means no separator
    1432     * @return this, to enable chaining
    1433     */
    1434    public TextStringBuilder appendWithSeparators(final Iterator<?> it, final String separator) {
    1435        if (it != null) {
    1436            final String sep = Objects.toString(separator, StringUtils.EMPTY);
    1437            while (it.hasNext()) {
    1438                append(it.next());
    1439                if (it.hasNext()) {
    1440                    append(sep);
    1441                }
    1442            }
    1443        }
    1444        return this;
    1445    }
    1446
    1447    /**
    1448     * Appends an array placing separators between each value, but not before the first or after the last. Appending a
    1449     * null array will have no effect. Each object is appended using {@link #append(Object)}.
    1450     *
    1451     * @param array the array to append
    1452     * @param separator the separator to use, null means no separator
    1453     * @return this, to enable chaining
    1454     */
    1455    public TextStringBuilder appendWithSeparators(final Object[] array, final String separator) {
    1456        if (array != null && array.length > 0) {
    1457            final String sep = Objects.toString(separator, StringUtils.EMPTY);
    1458            append(array[0]);
    1459            for (int i = 1; i < array.length; i++) {
    1460                append(sep);
    1461                append(array[i]);
    1462            }
    1463        }
    1464        return this;
    1465    }
    1466
    1467    /**
    1468     * Gets the contents of this builder as a Reader.
    1469     * <p>
    1470     * This method allows the contents of the builder to be read using any standard method that expects a Reader.
    1471     * </p>
    1472     * <p>
    1473     * To use, simply create a {@code StrBuilder}, populate it with data, call {@code asReader}, and then read away.
    1474     * </p>
    1475     * <p>
    1476     * The internal character array is shared between the builder and the reader. This allows you to append to the
    1477     * builder after creating the reader, and the changes will be picked up. Note however, that no synchronization
    1478     * occurs, so you must perform all operations with the builder and the reader in one thread.
    1479     * </p>
    1480     * <p>
    1481     * The returned reader supports marking, and ignores the flush method.
    1482     * </p>
    1483     *
    1484     * @return a reader that reads from this builder
    1485     */
    1486    public Reader asReader() {
    1487        return new TextStringBuilderReader();
    1488    }
    1489
    1490    /**
    1491     * Creates a tokenizer that can tokenize the contents of this builder.
    1492     * <p>
    1493     * This method allows the contents of this builder to be tokenized. The tokenizer will be setup by default to
    1494     * tokenize on space, tab, newline and form feed (as per StringTokenizer). These values can be changed on the
    1495     * tokenizer class, before retrieving the tokens.
    1496     * </p>
    1497     * <p>
    1498     * The returned tokenizer is linked to this builder. You may intermix calls to the builder and tokenizer within
    1499     * certain limits, however there is no synchronization. Once the tokenizer has been used once, it must be
    1500     * {@link StringTokenizer#reset() reset} to pickup the latest changes in the builder. For example:
    1501     * </p>
    1502     *
    1503     * <pre>
    1504     * StrBuilder b = new StrBuilder();
    1505     * b.append("a b ");
    1506     * StrTokenizer t = b.asTokenizer();
    1507     * String[] tokens1 = t.getTokenArray(); // returns a,b
    1508     * b.append("c d ");
    1509     * String[] tokens2 = t.getTokenArray(); // returns a,b (c and d ignored)
    1510     * t.reset(); // reset causes builder changes to be picked up
    1511     * String[] tokens3 = t.getTokenArray(); // returns a,b,c,d
    1512     * </pre>
    1513     *
    1514     * <p>
    1515     * In addition to simply intermixing appends and tokenization, you can also call the set methods on the tokenizer to
    1516     * alter how it tokenizes. Just remember to call reset when you want to pickup builder changes.
    1517     * </p>
    1518     * <p>
    1519     * Calling {@link StringTokenizer#reset(String)} or {@link StringTokenizer#reset(char[])} with a non-null value will
    1520     * break the link with the builder.
    1521     * </p>
    1522     *
    1523     * @return a tokenizer that is linked to this builder
    1524     */
    1525    public StringTokenizer asTokenizer() {
    1526        return new TextStringBuilderTokenizer();
    1527    }
    1528
    1529    /**
    1530     * Gets this builder as a Writer that can be written to.
    1531     * <p>
    1532     * This method allows you to populate the contents of the builder using any standard method that takes a Writer.
    1533     * </p>
    1534     * <p>
    1535     * To use, simply create a {@code StrBuilder}, call {@code asWriter}, and populate away. The data is available at
    1536     * any time using the methods of the {@code StrBuilder}.
    1537     * </p>
    1538     * <p>
    1539     * The internal character array is shared between the builder and the writer. This allows you to intermix calls that
    1540     * append to the builder and write using the writer and the changes will be occur correctly. Note however, that no
    1541     * synchronization occurs, so you must perform all operations with the builder and the writer in one thread.
    1542     * </p>
    1543     * <p>
    1544     * The returned writer ignores the close and flush methods.
    1545     * </p>
    1546     *
    1547     * @return a writer that populates this builder
    1548     */
    1549    public Writer asWriter() {
    1550        return new TextStringBuilderWriter();
    1551    }
    1552
    1553    /**
    1554     * Converts this instance to a String.
    1555     *
    1556     * @return This instance as a String
    1557     * @see #toString()
    1558     * @deprecated Use {@link #get()}.
    1559     */
    1560    @Deprecated
    1561    @Override
    1562    public String build() {
    1563        return toString();
    1564    }
    1565
    1566    /**
    1567     * Gets the current size of the internal character array buffer.
    1568     *
    1569     * @return The capacity
    1570     */
    1571    public int capacity() {
    1572        return buffer.length;
    1573    }
    1574
    1575    /**
    1576     * Gets the character at the specified index.
    1577     *
    1578     * @see #setCharAt(int, char)
    1579     * @see #deleteCharAt(int)
    1580     * @param index the index to retrieve, must be valid
    1581     * @return The character at the index
    1582     * @throws IndexOutOfBoundsException if the index is invalid
    1583     */
    1584    @Override
    1585    public char charAt(final int index) {
    1586        validateIndex(index);
    1587        return buffer[index];
    1588    }
    1589
    1590    /**
    1591     * Clears the string builder (convenience Collections API style method).
    1592     * <p>
    1593     * This method does not reduce the size of the internal character buffer. To do that, call {@code clear()} followed
    1594     * by {@link #minimizeCapacity()}.
    1595     * </p>
    1596     * <p>
    1597     * This method is the same as {@link #setLength(int)} called with zero and is provided to match the API of
    1598     * Collections.
    1599     * </p>
    1600     *
    1601     * @return this, to enable chaining
    1602     */
    1603    public TextStringBuilder clear() {
    1604        size = 0;
    1605        return this;
    1606    }
    1607
    1608    /**
    1609     * Tests if the string builder contains the specified char.
    1610     *
    1611     * @param ch the character to find
    1612     * @return true if the builder contains the character
    1613     */
    1614    public boolean contains(final char ch) {
    1615        final char[] thisBuf = buffer;
    1616        for (int i = 0; i < this.size; i++) {
    1617            if (thisBuf[i] == ch) {
    1618                return true;
    1619            }
    1620        }
    1621        return false;
    1622    }
    1623
    1624    /**
    1625     * Tests if the string builder contains the specified string.
    1626     *
    1627     * @param str the string to find
    1628     * @return true if the builder contains the string
    1629     */
    1630    public boolean contains(final String str) {
    1631        return indexOf(str, 0) >= 0;
    1632    }
    1633
    1634    /**
    1635     * Tests if the string builder contains a string matched using the specified matcher.
    1636     * <p>
    1637     * Matchers can be used to perform advanced searching behavior. For example you could write a matcher to search for
    1638     * the character 'a' followed by a number.
    1639     * </p>
    1640     *
    1641     * @param matcher the matcher to use, null returns -1
    1642     * @return true if the matcher finds a match in the builder
    1643     */
    1644    public boolean contains(final StringMatcher matcher) {
    1645        return indexOf(matcher, 0) >= 0;
    1646    }
    1647
    1648    /**
    1649     * Deletes the characters between the two specified indices.
    1650     *
    1651     * @param startIndex the start index, inclusive, must be valid
    1652     * @param endIndex the end index, exclusive, must be valid except that if too large it is treated as end of string
    1653     * @return this, to enable chaining
    1654     * @throws IndexOutOfBoundsException if the index is invalid
    1655     */
    1656    public TextStringBuilder delete(final int startIndex, final int endIndex) {
    1657        final int actualEndIndex = validateRange(startIndex, endIndex);
    1658        final int len = actualEndIndex - startIndex;
    1659        if (len > 0) {
    1660            deleteImpl(startIndex, actualEndIndex, len);
    1661        }
    1662        return this;
    1663    }
    1664
    1665    /**
    1666     * Deletes the character wherever it occurs in the builder.
    1667     *
    1668     * @param ch the character to delete
    1669     * @return this, to enable chaining
    1670     */
    1671    public TextStringBuilder deleteAll(final char ch) {
    1672        for (int i = 0; i < size; i++) {
    1673            if (buffer[i] == ch) {
    1674                final int start = i;
    1675                while (++i < size) {
    1676                    if (buffer[i] != ch) {
    1677                        break;
    1678                    }
    1679                }
    1680                final int len = i - start;
    1681                deleteImpl(start, i, len);
    1682                i -= len;
    1683            }
    1684        }
    1685        return this;
    1686    }
    1687
    1688    /**
    1689     * Deletes the string wherever it occurs in the builder.
    1690     *
    1691     * @param str the string to delete, null causes no action
    1692     * @return this, to enable chaining
    1693     */
    1694    public TextStringBuilder deleteAll(final String str) {
    1695        final int len = str == null ? 0 : str.length();
    1696        if (len > 0) {
    1697            int index = indexOf(str, 0);
    1698            while (index >= 0) {
    1699                deleteImpl(index, index + len, len);
    1700                index = indexOf(str, index);
    1701            }
    1702        }
    1703        return this;
    1704    }
    1705
    1706    /**
    1707     * Deletes all parts of the builder that the matcher matches.
    1708     * <p>
    1709     * Matchers can be used to perform advanced deletion behavior. For example you could write a matcher to delete all
    1710     * occurrences where the character 'a' is followed by a number.
    1711     * </p>
    1712     *
    1713     * @param matcher the matcher to use to find the deletion, null causes no action
    1714     * @return this, to enable chaining
    1715     */
    1716    public TextStringBuilder deleteAll(final StringMatcher matcher) {
    1717        return replace(matcher, null, 0, size, -1);
    1718    }
    1719
    1720    /**
    1721     * Deletes the character at the specified index.
    1722     *
    1723     * @see #charAt(int)
    1724     * @see #setCharAt(int, char)
    1725     * @param index the index to delete
    1726     * @return this, to enable chaining
    1727     * @throws IndexOutOfBoundsException if the index is invalid
    1728     */
    1729    public TextStringBuilder deleteCharAt(final int index) {
    1730        validateIndex(index);
    1731        deleteImpl(index, index + 1, 1);
    1732        return this;
    1733    }
    1734
    1735    /**
    1736     * Deletes the character wherever it occurs in the builder.
    1737     *
    1738     * @param ch the character to delete
    1739     * @return this, to enable chaining
    1740     */
    1741    public TextStringBuilder deleteFirst(final char ch) {
    1742        for (int i = 0; i < size; i++) {
    1743            if (buffer[i] == ch) {
    1744                deleteImpl(i, i + 1, 1);
    1745                break;
    1746            }
    1747        }
    1748        return this;
    1749    }
    1750
    1751    /**
    1752     * Deletes the string wherever it occurs in the builder.
    1753     *
    1754     * @param str the string to delete, null causes no action
    1755     * @return this, to enable chaining
    1756     */
    1757    public TextStringBuilder deleteFirst(final String str) {
    1758        final int len = str == null ? 0 : str.length();
    1759        if (len > 0) {
    1760            final int index = indexOf(str, 0);
    1761            if (index >= 0) {
    1762                deleteImpl(index, index + len, len);
    1763            }
    1764        }
    1765        return this;
    1766    }
    1767
    1768    /**
    1769     * Deletes the first match within the builder using the specified matcher.
    1770     * <p>
    1771     * Matchers can be used to perform advanced deletion behavior. For example you could write a matcher to delete where
    1772     * the character 'a' is followed by a number.
    1773     * </p>
    1774     *
    1775     * @param matcher the matcher to use to find the deletion, null causes no action
    1776     * @return this, to enable chaining
    1777     */
    1778    public TextStringBuilder deleteFirst(final StringMatcher matcher) {
    1779        return replace(matcher, null, 0, size, 1);
    1780    }
    1781
    1782    /**
    1783     * Internal method to delete a range without validation.
    1784     *
    1785     * @param startIndex the start index, must be valid
    1786     * @param endIndex the end index (exclusive), must be valid
    1787     * @param len the length, must be valid
    1788     * @throws IndexOutOfBoundsException if any index is invalid
    1789     */
    1790    private void deleteImpl(final int startIndex, final int endIndex, final int len) {
    1791        System.arraycopy(buffer, endIndex, buffer, startIndex, size - endIndex);
    1792        size -= len;
    1793    }
    1794
    1795    /**
    1796     * Gets the character at the specified index before deleting it.
    1797     *
    1798     * @see #charAt(int)
    1799     * @see #deleteCharAt(int)
    1800     * @param index the index to retrieve, must be valid
    1801     * @return The character at the index
    1802     * @throws IndexOutOfBoundsException if the index is invalid
    1803     * @since 1.9
    1804     */
    1805    public char drainChar(final int index) {
    1806        validateIndex(index);
    1807        final char c = buffer[index];
    1808        deleteCharAt(index);
    1809        return c;
    1810    }
    1811
    1812    /**
    1813     * Drains (copies, then deletes) this character sequence into the specified array. This is equivalent to copying the
    1814     * characters from this sequence into the target and then deleting those character from this sequence.
    1815     *
    1816     * @param startIndex first index to copy, inclusive.
    1817     * @param endIndex last index to copy, exclusive.
    1818     * @param target the target array, must not be {@code null}.
    1819     * @param targetIndex the index to start copying in the target.
    1820     * @return How many characters where copied (then deleted). If this builder is empty, return {@code 0}.
    1821     * @since 1.9
    1822     */
    1823    public int drainChars(final int startIndex, final int endIndex, final char[] target, final int targetIndex) {
    1824        final int length = endIndex - startIndex;
    1825        if (isEmpty() || length == 0 || target.length == 0) {
    1826            return 0;
    1827        }
    1828        final int actualLen = Math.min(Math.min(size, length), target.length - targetIndex);
    1829        getChars(startIndex, actualLen, target, targetIndex);
    1830        delete(startIndex, actualLen);
    1831        return actualLen;
    1832    }
    1833
    1834    /**
    1835     * Checks whether this builder ends with the specified string.
    1836     * <p>
    1837     * Note that this method handles null input quietly, unlike String.
    1838     * </p>
    1839     *
    1840     * @param str the string to search for, null returns false
    1841     * @return true if the builder ends with the string
    1842     */
    1843    public boolean endsWith(final String str) {
    1844        if (str == null) {
    1845            return false;
    1846        }
    1847        final int len = str.length();
    1848        if (len == 0) {
    1849            return true;
    1850        }
    1851        if (len > size) {
    1852            return false;
    1853        }
    1854        int pos = size - len;
    1855        for (int i = 0; i < len; i++, pos++) {
    1856            if (buffer[pos] != str.charAt(i)) {
    1857                return false;
    1858            }
    1859        }
    1860        return true;
    1861    }
    1862
    1863    /**
    1864     * Tests the capacity and ensures that it is at least the size specified.
    1865     *
    1866     * <p>
    1867     * Note: This method can be used to minimise memory reallocations during
    1868     * repeated addition of values by pre-allocating the character buffer.
    1869     * The method ignores a negative {@code capacity} argument.
    1870     * </p>
    1871     *
    1872     * @param capacity the capacity to ensure
    1873     * @return this, to enable chaining
    1874     * @throws OutOfMemoryError if the capacity cannot be allocated
    1875     */
    1876    public TextStringBuilder ensureCapacity(final int capacity) {
    1877        if (capacity > 0) {
    1878            ensureCapacityInternal(capacity);
    1879        }
    1880        return this;
    1881    }
    1882
    1883    /**
    1884     * Ensures that the buffer is at least the size specified. The {@code capacity} argument
    1885     * is treated as an unsigned integer.
    1886     *
    1887     * <p>
    1888     * This method will raise an {@link OutOfMemoryError} if the capacity is too large
    1889     * for an array, or cannot be allocated.
    1890     * </p>
    1891     *
    1892     * @param capacity the capacity to ensure
    1893     * @throws OutOfMemoryError if the capacity cannot be allocated
    1894     */
    1895    private void ensureCapacityInternal(final int capacity) {
    1896        // Check for overflow of the current buffer.
    1897        // Assumes capacity is an unsigned integer up to Integer.MAX_VALUE * 2
    1898        // (the largest possible addition of two maximum length arrays).
    1899        if (capacity - buffer.length > 0) {
    1900            resizeBuffer(capacity);
    1901        }
    1902    }
    1903
    1904    /**
    1905     * Tests the contents of this builder against another to see if they contain the same character content.
    1906     *
    1907     * @param obj the object to check, null returns false
    1908     * @return true if the builders contain the same characters in the same order
    1909     */
    1910    @Override
    1911    public boolean equals(final Object obj) {
    1912        return obj instanceof TextStringBuilder && equals((TextStringBuilder) obj);
    1913    }
    1914
    1915    /**
    1916     * Tests the contents of this builder against another to see if they contain the same character content.
    1917     *
    1918     * @param other the object to check, null returns false
    1919     * @return true if the builders contain the same characters in the same order
    1920     */
    1921    public boolean equals(final TextStringBuilder other) {
    1922        if (this == other) {
    1923            return true;
    1924        }
    1925        if (other == null) {
    1926            return false;
    1927        }
    1928        if (this.size != other.size) {
    1929            return false;
    1930        }
    1931        // Be aware not to use Arrays.equals(buffer, other.buffer) for equals() method
    1932        // as length of the buffers may be different (TEXT-211)
    1933        final char[] thisBuf = this.buffer;
    1934        final char[] otherBuf = other.buffer;
    1935        for (int i = size - 1; i >= 0; i--) {
    1936            if (thisBuf[i] != otherBuf[i]) {
    1937                return false;
    1938            }
    1939        }
    1940        return true;
    1941    }
    1942
    1943    /**
    1944     * Tests the contents of this builder against another to see if they contain the same character content ignoring
    1945     * case.
    1946     *
    1947     * @param other the object to check, null returns false
    1948     * @return true if the builders contain the same characters in the same order
    1949     */
    1950    public boolean equalsIgnoreCase(final TextStringBuilder other) {
    1951        if (this == other) {
    1952            return true;
    1953        }
    1954        if (this.size != other.size) {
    1955            return false;
    1956        }
    1957        final char[] thisBuf = this.buffer;
    1958        final char[] otherBuf = other.buffer;
    1959        for (int i = size - 1; i >= 0; i--) {
    1960            final char c1 = thisBuf[i];
    1961            final char c2 = otherBuf[i];
    1962            if (c1 != c2 && Character.toUpperCase(c1) != Character.toUpperCase(c2)) {
    1963                return false;
    1964            }
    1965        }
    1966        return true;
    1967    }
    1968
    1969    /**
    1970     * Converts this instance to a String.
    1971     *
    1972     * @return This instance as a String
    1973     * @see #toString()
    1974     * @since 1.12.0
    1975     */
    1976    @Override
    1977    public String get() {
    1978        return toString();
    1979    }
    1980
    1981    /**
    1982     * Gets a direct reference to internal storage, not for public consumption.
    1983     */
    1984    char[] getBuffer() {
    1985        return buffer;
    1986    }
    1987
    1988    /**
    1989     * Copies this character array into the specified array.
    1990     *
    1991     * @param target the target array, null will cause an array to be created
    1992     * @return The input array, unless that was null or too small
    1993     */
    1994    public char[] getChars(char[] target) {
    1995        final int len = length();
    1996        if (target == null || target.length < len) {
    1997            target = new char[len];
    1998        }
    1999        System.arraycopy(buffer, 0, target, 0, len);
    2000        return target;
    2001    }
    2002
    2003    /**
    2004     * Copies this character array into the specified array.
    2005     *
    2006     * @param startIndex first index to copy, inclusive, must be valid.
    2007     * @param endIndex last index to copy, exclusive, must be valid.
    2008     * @param target the target array, must not be null or too small.
    2009     * @param targetIndex the index to start copying in target.
    2010     * @throws NullPointerException if the array is null.
    2011     * @throws IndexOutOfBoundsException if any index is invalid.
    2012     */
    2013    public void getChars(final int startIndex, final int endIndex, final char[] target, final int targetIndex) {
    2014        if (startIndex < 0) {
    2015            throw new StringIndexOutOfBoundsException(startIndex);
    2016        }
    2017        if (endIndex < 0 || endIndex > length()) {
    2018            throw new StringIndexOutOfBoundsException(endIndex);
    2019        }
    2020        if (startIndex > endIndex) {
    2021            throw new StringIndexOutOfBoundsException("end < start");
    2022        }
    2023        System.arraycopy(buffer, startIndex, target, targetIndex, endIndex - startIndex);
    2024    }
    2025
    2026    /**
    2027     * Gets the text to be appended when a {@link #appendNewLine() new line} is added.
    2028     *
    2029     * @return The new line text, {@code null} means use the system default from {@link System#lineSeparator()}.
    2030     */
    2031    public String getNewLineText() {
    2032        return newLine;
    2033    }
    2034
    2035    /**
    2036     * Gets the text to be appended when null is added.
    2037     *
    2038     * @return The null text, null means no append
    2039     */
    2040    public String getNullText() {
    2041        return nullText;
    2042    }
    2043
    2044    /**
    2045     * Gets a suitable hash code for this builder.
    2046     *
    2047     * @return a hash code
    2048     */
    2049    @Override
    2050    public int hashCode() {
    2051        // no allocation
    2052        final char[] buf = buffer;
    2053        int result = 0;
    2054        for (int i = 0; i < size; i++) {
    2055            result = 31 * result + buf[i];
    2056        }
    2057        return result;
    2058    }
    2059
    2060    /**
    2061     * Searches the string builder to find the first reference to the specified char.
    2062     *
    2063     * @param ch the character to find
    2064     * @return The first index of the character, or -1 if not found
    2065     */
    2066    public int indexOf(final char ch) {
    2067        return indexOf(ch, 0);
    2068    }
    2069
    2070    /**
    2071     * Searches the string builder to find the first reference to the specified char.
    2072     *
    2073     * @param ch the character to find
    2074     * @param startIndex the index to start at, invalid index rounded to edge
    2075     * @return The first index of the character, or -1 if not found
    2076     */
    2077    public int indexOf(final char ch, int startIndex) {
    2078        startIndex = Math.max(0, startIndex);
    2079        if (startIndex >= size) {
    2080            return StringUtils.INDEX_NOT_FOUND;
    2081        }
    2082        final char[] thisBuf = buffer;
    2083        for (int i = startIndex; i < size; i++) {
    2084            if (thisBuf[i] == ch) {
    2085                return i;
    2086            }
    2087        }
    2088        return StringUtils.INDEX_NOT_FOUND;
    2089    }
    2090
    2091    /**
    2092     * Searches the string builder to find the first reference to the specified string.
    2093     * <p>
    2094     * Note that a null input string will return -1, whereas the JDK throws an exception.
    2095     * </p>
    2096     *
    2097     * @param str the string to find, null returns -1
    2098     * @return The first index of the string, or -1 if not found
    2099     */
    2100    public int indexOf(final String str) {
    2101        return indexOf(str, 0);
    2102    }
    2103
    2104    /**
    2105     * Searches the string builder to find the first reference to the specified string starting searching from the given
    2106     * index.
    2107     * <p>
    2108     * Note that a null input string will return -1, whereas the JDK throws an exception.
    2109     * </p>
    2110     *
    2111     * @param str the string to find, null returns -1
    2112     * @param startIndex the index to start at, invalid index rounded to edge
    2113     * @return The first index of the string, or -1 if not found
    2114     */
    2115    public int indexOf(final String str, int startIndex) {
    2116        startIndex = Math.max(0, startIndex);
    2117        if (str == null || startIndex >= size) {
    2118            return StringUtils.INDEX_NOT_FOUND;
    2119        }
    2120        final int strLen = str.length();
    2121        if (strLen == 1) {
    2122            return indexOf(str.charAt(0), startIndex);
    2123        }
    2124        if (strLen == 0) {
    2125            return startIndex;
    2126        }
    2127        if (strLen > size) {
    2128            return StringUtils.INDEX_NOT_FOUND;
    2129        }
    2130        final char[] thisBuf = buffer;
    2131        final int len = size - strLen + 1;
    2132        outer: for (int i = startIndex; i < len; i++) {
    2133            for (int j = 0; j < strLen; j++) {
    2134                if (str.charAt(j) != thisBuf[i + j]) {
    2135                    continue outer;
    2136                }
    2137            }
    2138            return i;
    2139        }
    2140        return StringUtils.INDEX_NOT_FOUND;
    2141    }
    2142
    2143    /**
    2144     * Searches the string builder using the matcher to find the first match.
    2145     * <p>
    2146     * Matchers can be used to perform advanced searching behavior. For example you could write a matcher to find the
    2147     * character 'a' followed by a number.
    2148     * </p>
    2149     *
    2150     * @param matcher the matcher to use, null returns -1
    2151     * @return The first index matched, or -1 if not found
    2152     */
    2153    public int indexOf(final StringMatcher matcher) {
    2154        return indexOf(matcher, 0);
    2155    }
    2156
    2157    /**
    2158     * Searches the string builder using the matcher to find the first match searching from the given index.
    2159     * <p>
    2160     * Matchers can be used to perform advanced searching behavior. For example you could write a matcher to find the
    2161     * character 'a' followed by a number.
    2162     * </p>
    2163     *
    2164     * @param matcher the matcher to use, null returns -1
    2165     * @param startIndex the index to start at, invalid index rounded to edge
    2166     * @return The first index matched, or -1 if not found
    2167     */
    2168    public int indexOf(final StringMatcher matcher, int startIndex) {
    2169        startIndex = Math.max(0, startIndex);
    2170        if (matcher == null || startIndex >= size) {
    2171            return StringUtils.INDEX_NOT_FOUND;
    2172        }
    2173        final int len = size;
    2174        final char[] buf = buffer;
    2175        for (int i = startIndex; i < len; i++) {
    2176            if (matcher.isMatch(buf, i, startIndex, len) > 0) {
    2177                return i;
    2178            }
    2179        }
    2180        return StringUtils.INDEX_NOT_FOUND;
    2181    }
    2182
    2183    /**
    2184     * Inserts the value into this builder.
    2185     *
    2186     * @param index the index to add at, must be valid
    2187     * @param value the value to insert
    2188     * @return this, to enable chaining
    2189     * @throws IndexOutOfBoundsException if the index is invalid
    2190     */
    2191    public TextStringBuilder insert(final int index, final boolean value) {
    2192        validateIndex(index);
    2193        if (value) {
    2194            ensureCapacityInternal(size + TRUE_STRING_SIZE);
    2195            System.arraycopy(buffer, index, buffer, index + TRUE_STRING_SIZE, size - index);
    2196            appendTrue(index);
    2197        } else {
    2198            ensureCapacityInternal(size + FALSE_STRING_SIZE);
    2199            System.arraycopy(buffer, index, buffer, index + FALSE_STRING_SIZE, size - index);
    2200            appendFalse(index);
    2201        }
    2202        return this;
    2203    }
    2204
    2205    /**
    2206     * Inserts the value into this builder.
    2207     *
    2208     * @param index the index to add at, must be valid
    2209     * @param value the value to insert
    2210     * @return this, to enable chaining
    2211     * @throws IndexOutOfBoundsException if the index is invalid
    2212     */
    2213    public TextStringBuilder insert(final int index, final char value) {
    2214        validateIndex(index);
    2215        ensureCapacityInternal(size + 1);
    2216        System.arraycopy(buffer, index, buffer, index + 1, size - index);
    2217        buffer[index] = value;
    2218        size++;
    2219        return this;
    2220    }
    2221
    2222    /**
    2223     * Inserts the character array into this builder. Inserting null will use the stored null text value.
    2224     *
    2225     * @param index the index to add at, must be valid
    2226     * @param chars the char array to insert
    2227     * @return this, to enable chaining
    2228     * @throws IndexOutOfBoundsException if the index is invalid
    2229     */
    2230    public TextStringBuilder insert(final int index, final char[] chars) {
    2231        validateIndex(index);
    2232        if (chars == null) {
    2233            return insert(index, nullText);
    2234        }
    2235        final int len = chars.length;
    2236        if (len > 0) {
    2237            ensureCapacityInternal(size + len);
    2238            System.arraycopy(buffer, index, buffer, index + len, size - index);
    2239            System.arraycopy(chars, 0, buffer, index, len);
    2240            size += len;
    2241        }
    2242        return this;
    2243    }
    2244
    2245    /**
    2246     * Inserts part of the character array into this builder. Inserting null will use the stored null text value.
    2247     *
    2248     * @param index the index to add at, must be valid
    2249     * @param chars the char array to insert
    2250     * @param offset the offset into the character array to start at, must be valid
    2251     * @param length the length of the character array part to copy, must be positive
    2252     * @return this, to enable chaining
    2253     * @throws IndexOutOfBoundsException if any index is invalid
    2254     */
    2255    public TextStringBuilder insert(final int index, final char[] chars, final int offset, final int length) {
    2256        validateIndex(index);
    2257        if (chars == null) {
    2258            return insert(index, nullText);
    2259        }
    2260        if (offset < 0 || offset > chars.length) {
    2261            throw new StringIndexOutOfBoundsException("Invalid offset: " + offset);
    2262        }
    2263        if (length < 0 || offset + length > chars.length) {
    2264            throw new StringIndexOutOfBoundsException("Invalid length: " + length);
    2265        }
    2266        if (length > 0) {
    2267            ensureCapacityInternal(size + length);
    2268            System.arraycopy(buffer, index, buffer, index + length, size - index);
    2269            System.arraycopy(chars, offset, buffer, index, length);
    2270            size += length;
    2271        }
    2272        return this;
    2273    }
    2274
    2275    /**
    2276     * Inserts the value into this builder.
    2277     *
    2278     * @param index the index to add at, must be valid
    2279     * @param value the value to insert
    2280     * @return this, to enable chaining
    2281     * @throws IndexOutOfBoundsException if the index is invalid
    2282     */
    2283    public TextStringBuilder insert(final int index, final double value) {
    2284        return insert(index, String.valueOf(value));
    2285    }
    2286
    2287    /**
    2288     * Inserts the value into this builder.
    2289     *
    2290     * @param index the index to add at, must be valid
    2291     * @param value the value to insert
    2292     * @return this, to enable chaining
    2293     * @throws IndexOutOfBoundsException if the index is invalid
    2294     */
    2295    public TextStringBuilder insert(final int index, final float value) {
    2296        return insert(index, String.valueOf(value));
    2297    }
    2298
    2299    /**
    2300     * Inserts the value into this builder.
    2301     *
    2302     * @param index the index to add at, must be valid
    2303     * @param value the value to insert
    2304     * @return this, to enable chaining
    2305     * @throws IndexOutOfBoundsException if the index is invalid
    2306     */
    2307    public TextStringBuilder insert(final int index, final int value) {
    2308        return insert(index, String.valueOf(value));
    2309    }
    2310
    2311    /**
    2312     * Inserts the value into this builder.
    2313     *
    2314     * @param index the index to add at, must be valid
    2315     * @param value the value to insert
    2316     * @return this, to enable chaining
    2317     * @throws IndexOutOfBoundsException if the index is invalid
    2318     */
    2319    public TextStringBuilder insert(final int index, final long value) {
    2320        return insert(index, String.valueOf(value));
    2321    }
    2322
    2323    /**
    2324     * Inserts the string representation of an object into this builder. Inserting null will use the stored null text
    2325     * value.
    2326     *
    2327     * @param index the index to add at, must be valid
    2328     * @param obj the object to insert
    2329     * @return this, to enable chaining
    2330     * @throws IndexOutOfBoundsException if the index is invalid
    2331     */
    2332    public TextStringBuilder insert(final int index, final Object obj) {
    2333        if (obj == null) {
    2334            return insert(index, nullText);
    2335        }
    2336        return insert(index, obj.toString());
    2337    }
    2338
    2339    /**
    2340     * Inserts the string into this builder. Inserting null will use the stored null text value.
    2341     *
    2342     * @param index the index to add at, must be valid
    2343     * @param str the string to insert
    2344     * @return this, to enable chaining
    2345     * @throws IndexOutOfBoundsException if the index is invalid
    2346     */
    2347    public TextStringBuilder insert(final int index, String str) {
    2348        validateIndex(index);
    2349        if (str == null) {
    2350            str = nullText;
    2351        }
    2352        if (str != null) {
    2353            final int strLen = str.length();
    2354            if (strLen > 0) {
    2355                final int newSize = size + strLen;
    2356                ensureCapacityInternal(newSize);
    2357                System.arraycopy(buffer, index, buffer, index + strLen, size - index);
    2358                size = newSize;
    2359                str.getChars(0, strLen, buffer, index);
    2360            }
    2361        }
    2362        return this;
    2363    }
    2364
    2365    /**
    2366     * Checks is the string builder is empty (convenience Collections API style method).
    2367     * <p>
    2368     * This method is the same as checking {@link #length()} and is provided to match the API of Collections.
    2369     * </p>
    2370     *
    2371     * @return {@code true} if the size is {@code 0}.
    2372     */
    2373    public boolean isEmpty() {
    2374        return size == 0;
    2375    }
    2376
    2377    /**
    2378     * Checks is the string builder is not empty.
    2379     * <p>
    2380     * This method is the same as checking {@link #length()}.
    2381     * </p>
    2382     *
    2383     * @return {@code true} if the size is not {@code 0}.
    2384     * @since 1.9
    2385     */
    2386    public boolean isNotEmpty() {
    2387        return size != 0;
    2388    }
    2389
    2390    /**
    2391     * Gets whether the internal buffer has been reallocated.
    2392     *
    2393     * @return Whether the internal buffer has been reallocated.
    2394     * @since 1.9
    2395     */
    2396    public boolean isReallocated() {
    2397        return reallocations > 0;
    2398    }
    2399
    2400    /**
    2401     * Searches the string builder to find the last reference to the specified char.
    2402     *
    2403     * @param ch the character to find
    2404     * @return The last index of the character, or -1 if not found
    2405     */
    2406    public int lastIndexOf(final char ch) {
    2407        return lastIndexOf(ch, size - 1);
    2408    }
    2409
    2410    /**
    2411     * Searches the string builder to find the last reference to the specified char.
    2412     *
    2413     * @param ch the character to find
    2414     * @param startIndex the index to start at, invalid index rounded to edge
    2415     * @return The last index of the character, or -1 if not found
    2416     */
    2417    public int lastIndexOf(final char ch, int startIndex) {
    2418        startIndex = startIndex >= size ? size - 1 : startIndex;
    2419        if (startIndex < 0) {
    2420            return StringUtils.INDEX_NOT_FOUND;
    2421        }
    2422        for (int i = startIndex; i >= 0; i--) {
    2423            if (buffer[i] == ch) {
    2424                return i;
    2425            }
    2426        }
    2427        return StringUtils.INDEX_NOT_FOUND;
    2428    }
    2429
    2430    /**
    2431     * Searches the string builder to find the last reference to the specified string.
    2432     * <p>
    2433     * Note that a null input string will return -1, whereas the JDK throws an exception.
    2434     * </p>
    2435     *
    2436     * @param str the string to find, null returns -1
    2437     * @return The last index of the string, or -1 if not found
    2438     */
    2439    public int lastIndexOf(final String str) {
    2440        return lastIndexOf(str, size - 1);
    2441    }
    2442
    2443    /**
    2444     * Searches the string builder to find the last reference to the specified string starting searching from the given
    2445     * index.
    2446     * <p>
    2447     * Note that a null input string will return -1, whereas the JDK throws an exception.
    2448     * </p>
    2449     *
    2450     * @param str the string to find, null returns -1
    2451     * @param startIndex the index to start at, invalid index rounded to edge
    2452     * @return The last index of the string, or -1 if not found
    2453     */
    2454    public int lastIndexOf(final String str, int startIndex) {
    2455        startIndex = startIndex >= size ? size - 1 : startIndex;
    2456        if (str == null || startIndex < 0) {
    2457            return StringUtils.INDEX_NOT_FOUND;
    2458        }
    2459        final int strLen = str.length();
    2460        if (strLen > 0 && strLen <= size) {
    2461            if (strLen == 1) {
    2462                return lastIndexOf(str.charAt(0), startIndex);
    2463            }
    2464
    2465            outer: for (int i = startIndex - strLen + 1; i >= 0; i--) {
    2466                for (int j = 0; j < strLen; j++) {
    2467                    if (str.charAt(j) != buffer[i + j]) {
    2468                        continue outer;
    2469                    }
    2470                }
    2471                return i;
    2472            }
    2473
    2474        } else if (strLen == 0) {
    2475            return startIndex;
    2476        }
    2477        return StringUtils.INDEX_NOT_FOUND;
    2478    }
    2479
    2480    /**
    2481     * Searches the string builder using the matcher to find the last match.
    2482     * <p>
    2483     * Matchers can be used to perform advanced searching behavior. For example you could write a matcher to find the
    2484     * character 'a' followed by a number.
    2485     * </p>
    2486     *
    2487     * @param matcher the matcher to use, null returns -1
    2488     * @return The last index matched, or -1 if not found
    2489     */
    2490    public int lastIndexOf(final StringMatcher matcher) {
    2491        return lastIndexOf(matcher, size);
    2492    }
    2493
    2494    /**
    2495     * Searches the string builder using the matcher to find the last match searching from the given index.
    2496     * <p>
    2497     * Matchers can be used to perform advanced searching behavior. For example you could write a matcher to find the
    2498     * character 'a' followed by a number.
    2499     * </p>
    2500     *
    2501     * @param matcher the matcher to use, null returns -1
    2502     * @param startIndex the index to start at, invalid index rounded to edge
    2503     * @return The last index matched, or -1 if not found
    2504     */
    2505    public int lastIndexOf(final StringMatcher matcher, int startIndex) {
    2506        startIndex = startIndex >= size ? size - 1 : startIndex;
    2507        if (matcher == null || startIndex < 0) {
    2508            return StringUtils.INDEX_NOT_FOUND;
    2509        }
    2510        final char[] buf = buffer;
    2511        final int endIndex = startIndex + 1;
    2512        for (int i = startIndex; i >= 0; i--) {
    2513            if (matcher.isMatch(buf, i, 0, endIndex) > 0) {
    2514                return i;
    2515            }
    2516        }
    2517        return StringUtils.INDEX_NOT_FOUND;
    2518    }
    2519
    2520    /**
    2521     * Extracts the leftmost characters from the string builder without throwing an exception.
    2522     * <p>
    2523     * This method extracts the left {@code length} characters from the builder. If this many characters are not
    2524     * available, the whole builder is returned. Thus the returned string may be shorter than the length requested.
    2525     * </p>
    2526     *
    2527     * @param length the number of characters to extract, negative returns empty string
    2528     * @return The new string
    2529     */
    2530    public String leftString(final int length) {
    2531        if (length <= 0) {
    2532            return StringUtils.EMPTY;
    2533        }
    2534        if (length >= size) {
    2535            return new String(buffer, 0, size);
    2536        }
    2537        return new String(buffer, 0, length);
    2538    }
    2539
    2540    /**
    2541     * Gets the length of the string builder.
    2542     *
    2543     * @return The length
    2544     */
    2545    @Override
    2546    public int length() {
    2547        return size;
    2548    }
    2549
    2550    /**
    2551     * Extracts some characters from the middle of the string builder without throwing an exception.
    2552     * <p>
    2553     * This method extracts {@code length} characters from the builder at the specified index. If the index is negative
    2554     * it is treated as zero. If the index is greater than the builder size, it is treated as the builder size. If the
    2555     * length is negative, the empty string is returned. If insufficient characters are available in the builder, as
    2556     * much as possible is returned. Thus the returned string may be shorter than the length requested.
    2557     * </p>
    2558     *
    2559     * @param index the index to start at, negative means zero
    2560     * @param length the number of characters to extract, negative returns empty string
    2561     * @return The new string
    2562     */
    2563    public String midString(int index, final int length) {
    2564        if (index < 0) {
    2565            index = 0;
    2566        }
    2567        if (length <= 0 || index >= size) {
    2568            return StringUtils.EMPTY;
    2569        }
    2570        if (size <= index + length) {
    2571            return new String(buffer, index, size - index);
    2572        }
    2573        return new String(buffer, index, length);
    2574    }
    2575
    2576    /**
    2577     * Minimizes the capacity to the actual length of the string.
    2578     *
    2579     * @return this, to enable chaining
    2580     */
    2581    public TextStringBuilder minimizeCapacity() {
    2582        if (buffer.length > size) {
    2583            reallocate(size);
    2584        }
    2585        return this;
    2586    }
    2587
    2588    /**
    2589     * If possible, reads chars from the provided {@link CharBuffer} directly into underlying character buffer without
    2590     * making extra copies.
    2591     *
    2592     * @param charBuffer CharBuffer to read.
    2593     * @return The number of characters read.
    2594     * @see #appendTo(Appendable)
    2595     * @since 1.9
    2596     */
    2597    public int readFrom(final CharBuffer charBuffer) {
    2598        final int oldSize = size;
    2599        final int remaining = charBuffer.remaining();
    2600        ensureCapacityInternal(size + remaining);
    2601        charBuffer.get(buffer, size, remaining);
    2602        size += remaining;
    2603        return size - oldSize;
    2604    }
    2605
    2606    /**
    2607     * If possible, reads all chars from the provided {@link Readable} directly into underlying character buffer without
    2608     * making extra copies.
    2609     *
    2610     * @param readable object to read from
    2611     * @return The number of characters read
    2612     * @throws IOException if an I/O error occurs.
    2613     * @see #appendTo(Appendable)
    2614     */
    2615    public int readFrom(final Readable readable) throws IOException {
    2616        if (readable instanceof Reader) {
    2617            return readFrom((Reader) readable);
    2618        }
    2619        if (readable instanceof CharBuffer) {
    2620            return readFrom((CharBuffer) readable);
    2621        }
    2622        final int oldSize = size;
    2623        while (true) {
    2624            ensureCapacityInternal(size + 1);
    2625            final CharBuffer buf = CharBuffer.wrap(buffer, size, buffer.length - size);
    2626            final int read = readable.read(buf);
    2627            if (read == EOS) {
    2628                break;
    2629            }
    2630            size += read;
    2631        }
    2632        return size - oldSize;
    2633    }
    2634
    2635    /**
    2636     * If possible, reads all chars from the provided {@link Reader} directly into underlying character buffer without
    2637     * making extra copies.
    2638     *
    2639     * @param reader Reader to read.
    2640     * @return The number of characters read or -1 if we reached the end of stream.
    2641     * @throws IOException if an I/O error occurs.
    2642     * @see #appendTo(Appendable)
    2643     * @since 1.9
    2644     */
    2645    public int readFrom(final Reader reader) throws IOException {
    2646        final int oldSize = size;
    2647        ensureCapacityInternal(size + 1);
    2648        int readCount = reader.read(buffer, size, buffer.length - size);
    2649        if (readCount == EOS) {
    2650            return EOS;
    2651        }
    2652        do {
    2653            size += readCount;
    2654            ensureCapacityInternal(size + 1);
    2655            readCount = reader.read(buffer, size, buffer.length - size);
    2656        } while (readCount != EOS);
    2657        return size - oldSize;
    2658    }
    2659
    2660    /**
    2661     * If possible, reads {@code count} chars from the provided {@link Reader} directly into underlying character buffer
    2662     * without making extra copies.
    2663     *
    2664     * @param reader Reader to read.
    2665     * @param count The maximum characters to read, a value &lt;= 0 returns 0.
    2666     * @return The number of characters read. If less than {@code count}, then we've reached the end-of-stream, or -1 if
    2667     *         we reached the end of stream.
    2668     * @throws IOException if an I/O error occurs.
    2669     * @see #appendTo(Appendable)
    2670     * @since 1.9
    2671     */
    2672    public int readFrom(final Reader reader, final int count) throws IOException {
    2673        if (count <= 0) {
    2674            return 0;
    2675        }
    2676        final int oldSize = size;
    2677        ensureCapacityInternal(size + count);
    2678        int target = count;
    2679        int readCount = reader.read(buffer, size, target);
    2680        if (readCount == EOS) {
    2681            return EOS;
    2682        }
    2683        do {
    2684            target -= readCount;
    2685            size += readCount;
    2686            readCount = reader.read(buffer, size, target);
    2687        } while (target > 0 && readCount != EOS);
    2688        return size - oldSize;
    2689    }
    2690
    2691    /**
    2692     * Reallocates the buffer to the new length.
    2693     *
    2694     * @param newLength the length of the copy to be returned
    2695     */
    2696    private void reallocate(final int newLength) {
    2697        this.buffer = Arrays.copyOf(buffer, newLength);
    2698        this.reallocations++;
    2699    }
    2700
    2701    /**
    2702     * Replaces a portion of the string builder with another string. The length of the inserted string does not have to
    2703     * match the removed length.
    2704     *
    2705     * @param startIndex the start index, inclusive, must be valid
    2706     * @param endIndex the end index, exclusive, must be valid except that if too large it is treated as end of string
    2707     * @param replaceStr the string to replace with, null means delete range
    2708     * @return this, to enable chaining
    2709     * @throws IndexOutOfBoundsException if the index is invalid
    2710     */
    2711    public TextStringBuilder replace(final int startIndex, int endIndex, final String replaceStr) {
    2712        endIndex = validateRange(startIndex, endIndex);
    2713        final int insertLen = replaceStr == null ? 0 : replaceStr.length();
    2714        replaceImpl(startIndex, endIndex, endIndex - startIndex, replaceStr, insertLen);
    2715        return this;
    2716    }
    2717
    2718    /**
    2719     * Advanced search and replaces within the builder using a matcher.
    2720     * <p>
    2721     * Matchers can be used to perform advanced behavior. For example you could write a matcher to delete all
    2722     * occurrences where the character 'a' is followed by a number.
    2723     * </p>
    2724     *
    2725     * @param matcher the matcher to use to find the deletion, null causes no action
    2726     * @param replaceStr the string to replace the match with, null is a delete
    2727     * @param startIndex the start index, inclusive, must be valid
    2728     * @param endIndex the end index, exclusive, must be valid except that if too large it is treated as end of string
    2729     * @param replaceCount the number of times to replace, -1 for replace all
    2730     * @return this, to enable chaining
    2731     * @throws IndexOutOfBoundsException if start index is invalid
    2732     */
    2733    public TextStringBuilder replace(final StringMatcher matcher, final String replaceStr, final int startIndex,
    2734        int endIndex, final int replaceCount) {
    2735        endIndex = validateRange(startIndex, endIndex);
    2736        return replaceImpl(matcher, replaceStr, startIndex, endIndex, replaceCount);
    2737    }
    2738
    2739    /**
    2740     * Replaces the search character with the replace character throughout the builder.
    2741     *
    2742     * @param search the search character
    2743     * @param replace the replace character
    2744     * @return this, to enable chaining
    2745     */
    2746    public TextStringBuilder replaceAll(final char search, final char replace) {
    2747        if (search != replace) {
    2748            for (int i = 0; i < size; i++) {
    2749                if (buffer[i] == search) {
    2750                    buffer[i] = replace;
    2751                }
    2752            }
    2753        }
    2754        return this;
    2755    }
    2756
    2757    /**
    2758     * Replaces the search string with the replace string throughout the builder.
    2759     *
    2760     * @param searchStr the search string, null causes no action to occur
    2761     * @param replaceStr the replace string, null is equivalent to an empty string
    2762     * @return this, to enable chaining
    2763     */
    2764    public TextStringBuilder replaceAll(final String searchStr, final String replaceStr) {
    2765        final int searchLen = searchStr == null ? 0 : searchStr.length();
    2766        if (searchLen > 0) {
    2767            final int replaceLen = replaceStr == null ? 0 : replaceStr.length();
    2768            int index = indexOf(searchStr, 0);
    2769            while (index >= 0) {
    2770                replaceImpl(index, index + searchLen, searchLen, replaceStr, replaceLen);
    2771                index = indexOf(searchStr, index + replaceLen);
    2772            }
    2773        }
    2774        return this;
    2775    }
    2776
    2777    /**
    2778     * Replaces all matches within the builder with the replace string.
    2779     * <p>
    2780     * Matchers can be used to perform advanced replace behavior. For example you could write a matcher to replace all
    2781     * occurrences where the character 'a' is followed by a number.
    2782     * </p>
    2783     *
    2784     * @param matcher the matcher to use to find the deletion, null causes no action
    2785     * @param replaceStr the replace string, null is equivalent to an empty string
    2786     * @return this, to enable chaining
    2787     */
    2788    public TextStringBuilder replaceAll(final StringMatcher matcher, final String replaceStr) {
    2789        return replace(matcher, replaceStr, 0, size, -1);
    2790    }
    2791
    2792    /**
    2793     * Replaces the first instance of the search character with the replace character in the builder.
    2794     *
    2795     * @param search the search character
    2796     * @param replace the replace character
    2797     * @return this, to enable chaining
    2798     */
    2799    public TextStringBuilder replaceFirst(final char search, final char replace) {
    2800        if (search != replace) {
    2801            for (int i = 0; i < size; i++) {
    2802                if (buffer[i] == search) {
    2803                    buffer[i] = replace;
    2804                    break;
    2805                }
    2806            }
    2807        }
    2808        return this;
    2809    }
    2810
    2811    /**
    2812     * Replaces the first instance of the search string with the replace string.
    2813     *
    2814     * @param searchStr the search string, null causes no action to occur
    2815     * @param replaceStr the replace string, null is equivalent to an empty string
    2816     * @return this, to enable chaining
    2817     */
    2818    public TextStringBuilder replaceFirst(final String searchStr, final String replaceStr) {
    2819        final int searchLen = searchStr == null ? 0 : searchStr.length();
    2820        if (searchLen > 0) {
    2821            final int index = indexOf(searchStr, 0);
    2822            if (index >= 0) {
    2823                final int replaceLen = replaceStr == null ? 0 : replaceStr.length();
    2824                replaceImpl(index, index + searchLen, searchLen, replaceStr, replaceLen);
    2825            }
    2826        }
    2827        return this;
    2828    }
    2829
    2830    /**
    2831     * Replaces the first match within the builder with the replace string.
    2832     * <p>
    2833     * Matchers can be used to perform advanced replace behavior. For example you could write a matcher to replace where
    2834     * the character 'a' is followed by a number.
    2835     * </p>
    2836     *
    2837     * @param matcher the matcher to use to find the deletion, null causes no action
    2838     * @param replaceStr the replace string, null is equivalent to an empty string
    2839     * @return this, to enable chaining
    2840     */
    2841    public TextStringBuilder replaceFirst(final StringMatcher matcher, final String replaceStr) {
    2842        return replace(matcher, replaceStr, 0, size, 1);
    2843    }
    2844
    2845    /**
    2846     * Internal method to delete a range without validation.
    2847     *
    2848     * @param startIndex the start index, must be valid
    2849     * @param endIndex the end index (exclusive), must be valid
    2850     * @param removeLen the length to remove (endIndex - startIndex), must be valid
    2851     * @param insertStr the string to replace with, null means delete range
    2852     * @param insertLen the length of the insert string, must be valid
    2853     * @throws IndexOutOfBoundsException if any index is invalid
    2854     */
    2855    private void replaceImpl(final int startIndex, final int endIndex, final int removeLen, final String insertStr,
    2856        final int insertLen) {
    2857        final int newSize = size - removeLen + insertLen;
    2858        if (insertLen != removeLen) {
    2859            ensureCapacityInternal(newSize);
    2860            System.arraycopy(buffer, endIndex, buffer, startIndex + insertLen, size - endIndex);
    2861            size = newSize;
    2862        }
    2863        if (insertLen > 0) {
    2864            insertStr.getChars(0, insertLen, buffer, startIndex);
    2865        }
    2866    }
    2867
    2868    /**
    2869     * Replaces within the builder using a matcher.
    2870     * <p>
    2871     * Matchers can be used to perform advanced behavior. For example you could write a matcher to delete all
    2872     * occurrences where the character 'a' is followed by a number.
    2873     * </p>
    2874     *
    2875     * @param matcher the matcher to use to find the deletion, null causes no action
    2876     * @param replaceStr the string to replace the match with, null is a delete
    2877     * @param from the start index, must be valid
    2878     * @param to the end index (exclusive), must be valid
    2879     * @param replaceCount the number of times to replace, -1 for replace all
    2880     * @return this, to enable chaining
    2881     * @throws IndexOutOfBoundsException if any index is invalid
    2882     */
    2883    private TextStringBuilder replaceImpl(final StringMatcher matcher, final String replaceStr, final int from, int to,
    2884        int replaceCount) {
    2885        if (matcher == null || size == 0) {
    2886            return this;
    2887        }
    2888        final int replaceLen = replaceStr == null ? 0 : replaceStr.length();
    2889        for (int i = from; i < to && replaceCount != 0; i++) {
    2890            final char[] buf = buffer;
    2891            final int removeLen = matcher.isMatch(buf, i, from, to);
    2892            if (removeLen > 0) {
    2893                replaceImpl(i, i + removeLen, removeLen, replaceStr, replaceLen);
    2894                to = to - removeLen + replaceLen;
    2895                i = i + replaceLen - 1;
    2896                if (replaceCount > 0) {
    2897                    replaceCount--;
    2898                }
    2899            }
    2900        }
    2901        return this;
    2902    }
    2903
    2904    /**
    2905     * Resizes the buffer to at least the size specified.
    2906     *
    2907     * @param minCapacity the minimum required capacity
    2908     * @throws OutOfMemoryError if the {@code minCapacity} is negative
    2909     */
    2910    private void resizeBuffer(final int minCapacity) {
    2911        // Overflow-conscious code treats the min and new capacity as unsigned.
    2912        final int oldCapacity = buffer.length;
    2913        int newCapacity = oldCapacity * 2;
    2914        if (Integer.compareUnsigned(newCapacity, minCapacity) < 0) {
    2915            newCapacity = minCapacity;
    2916        }
    2917        if (Integer.compareUnsigned(newCapacity, MAX_BUFFER_SIZE) > 0) {
    2918            newCapacity = createPositiveCapacity(minCapacity);
    2919        }
    2920        reallocate(newCapacity);
    2921    }
    2922
    2923    /**
    2924     * Reverses the string builder placing each character in the opposite index.
    2925     *
    2926     * @return this, to enable chaining
    2927     */
    2928    public TextStringBuilder reverse() {
    2929        if (size == 0) {
    2930            return this;
    2931        }
    2932
    2933        final int half = size / 2;
    2934        final char[] buf = buffer;
    2935        for (int leftIdx = 0, rightIdx = size - 1; leftIdx < half; leftIdx++, rightIdx--) {
    2936            final char swap = buf[leftIdx];
    2937            buf[leftIdx] = buf[rightIdx];
    2938            buf[rightIdx] = swap;
    2939        }
    2940        return this;
    2941    }
    2942
    2943    /**
    2944     * Extracts the rightmost characters from the string builder without throwing an exception.
    2945     * <p>
    2946     * This method extracts the right {@code length} characters from the builder. If this many characters are not
    2947     * available, the whole builder is returned. Thus the returned string may be shorter than the length requested.
    2948     * </p>
    2949     *
    2950     * @param length the number of characters to extract, negative returns empty string
    2951     * @return The new string
    2952     */
    2953    public String rightString(final int length) {
    2954        if (length <= 0) {
    2955            return StringUtils.EMPTY;
    2956        }
    2957        if (length >= size) {
    2958            return new String(buffer, 0, size);
    2959        }
    2960        return new String(buffer, size - length, length);
    2961    }
    2962
    2963    /**
    2964     * Clears and sets this builder to the given value.
    2965     *
    2966     * @see #charAt(int)
    2967     * @see #deleteCharAt(int)
    2968     * @param str the new value.
    2969     * @return this, to enable chaining
    2970     * @since 1.9
    2971     */
    2972    public TextStringBuilder set(final CharSequence str) {
    2973        clear();
    2974        append(str);
    2975        return this;
    2976    }
    2977
    2978    /**
    2979     * Sets the character at the specified index.
    2980     *
    2981     * @see #charAt(int)
    2982     * @see #deleteCharAt(int)
    2983     * @param index the index to set
    2984     * @param ch the new character
    2985     * @return this, to enable chaining
    2986     * @throws IndexOutOfBoundsException if the index is invalid
    2987     */
    2988    public TextStringBuilder setCharAt(final int index, final char ch) {
    2989        validateIndex(index);
    2990        buffer[index] = ch;
    2991        return this;
    2992    }
    2993
    2994    /**
    2995     * Updates the length of the builder by either dropping the last characters or adding filler of Unicode zero.
    2996     *
    2997     * @param length the length to set to, must be zero or positive
    2998     * @return this, to enable chaining
    2999     * @throws IndexOutOfBoundsException if the length is negative
    3000     */
    3001    public TextStringBuilder setLength(final int length) {
    3002        if (length < 0) {
    3003            throw new StringIndexOutOfBoundsException(length);
    3004        }
    3005        if (length < size) {
    3006            size = length;
    3007        } else if (length > size) {
    3008            ensureCapacityInternal(length);
    3009            final int oldEnd = size;
    3010            size = length;
    3011            Arrays.fill(buffer, oldEnd, length, '\0');
    3012        }
    3013        return this;
    3014    }
    3015
    3016    /**
    3017     * Sets the text to be appended when {@link #appendNewLine() new line} is called.
    3018     *
    3019     * @param newLine the new line text, {@code null} means use the system default from {@link System#lineSeparator()}.
    3020     * @return this instance.
    3021     */
    3022    public TextStringBuilder setNewLineText(final String newLine) {
    3023        this.newLine = newLine;
    3024        return this;
    3025    }
    3026
    3027    /**
    3028     * Sets the text to be appended when null is added.
    3029     *
    3030     * @param nullText the null text, null means no append
    3031     * @return this, to enable chaining
    3032     */
    3033    public TextStringBuilder setNullText(String nullText) {
    3034        if (nullText != null && nullText.isEmpty()) {
    3035            nullText = null;
    3036        }
    3037        this.nullText = nullText;
    3038        return this;
    3039    }
    3040
    3041    /**
    3042     * Gets the length of the string builder.
    3043     * <p>
    3044     * This method is the same as {@link #length()} and is provided to match the API of Collections.
    3045     * </p>
    3046     *
    3047     * @return The length
    3048     */
    3049    public int size() {
    3050        return size;
    3051    }
    3052
    3053    /**
    3054     * Checks whether this builder starts with the specified string.
    3055     * <p>
    3056     * Note that this method handles null input quietly, unlike String.
    3057     * </p>
    3058     *
    3059     * @param str the string to search for, null returns false
    3060     * @return true if the builder starts with the string
    3061     */
    3062    public boolean startsWith(final String str) {
    3063        if (str == null) {
    3064            return false;
    3065        }
    3066        final int len = str.length();
    3067        if (len == 0) {
    3068            return true;
    3069        }
    3070        if (len > size) {
    3071            return false;
    3072        }
    3073        for (int i = 0; i < len; i++) {
    3074            if (buffer[i] != str.charAt(i)) {
    3075                return false;
    3076            }
    3077        }
    3078        return true;
    3079    }
    3080
    3081    /**
    3082     * {@inheritDoc}
    3083     */
    3084    @Override
    3085    public CharSequence subSequence(final int startIndex, final int endIndex) {
    3086        if (startIndex < 0) {
    3087            throw new StringIndexOutOfBoundsException(startIndex);
    3088        }
    3089        if (endIndex > size) {
    3090            throw new StringIndexOutOfBoundsException(endIndex);
    3091        }
    3092        if (startIndex > endIndex) {
    3093            throw new StringIndexOutOfBoundsException(endIndex - startIndex);
    3094        }
    3095        return substring(startIndex, endIndex);
    3096    }
    3097
    3098    /**
    3099     * Extracts a portion of this string builder as a string.
    3100     *
    3101     * @param start the start index, inclusive, must be valid
    3102     * @return The new string
    3103     * @throws IndexOutOfBoundsException if the index is invalid
    3104     */
    3105    public String substring(final int start) {
    3106        return substring(start, size);
    3107    }
    3108
    3109    /**
    3110     * Extracts a portion of this string builder as a string.
    3111     * <p>
    3112     * Note: This method treats an endIndex greater than the length of the builder as equal to the length of the
    3113     * builder, and continues without error, unlike StringBuffer or String.
    3114     * </p>
    3115     *
    3116     * @param startIndex the start index, inclusive, must be valid
    3117     * @param endIndex the end index, exclusive, must be valid except that if too large it is treated as end of string
    3118     * @return The new string
    3119     * @throws IndexOutOfBoundsException if the index is invalid
    3120     */
    3121    public String substring(final int startIndex, int endIndex) {
    3122        endIndex = validateRange(startIndex, endIndex);
    3123        return new String(buffer, startIndex, endIndex - startIndex);
    3124    }
    3125
    3126    /**
    3127     * Copies the builder's character array into a new character array.
    3128     *
    3129     * @return a new array that represents the contents of the builder
    3130     */
    3131    public char[] toCharArray() {
    3132        return size == 0 ? ArrayUtils.EMPTY_CHAR_ARRAY : Arrays.copyOf(buffer, size);
    3133    }
    3134
    3135    /**
    3136     * Copies part of the builder's character array into a new character array.
    3137     *
    3138     * @param startIndex the start index, inclusive, must be valid
    3139     * @param endIndex the end index, exclusive, must be valid except that if too large it is treated as end of string
    3140     * @return a new array that holds part of the contents of the builder
    3141     * @throws IndexOutOfBoundsException if startIndex is invalid, or if endIndex is invalid (but endIndex greater than
    3142     *         size is valid)
    3143     */
    3144    public char[] toCharArray(final int startIndex, int endIndex) {
    3145        endIndex = validateRange(startIndex, endIndex);
    3146        final int len = endIndex - startIndex;
    3147        return len == 0 ? ArrayUtils.EMPTY_CHAR_ARRAY : Arrays.copyOfRange(buffer, startIndex, endIndex);
    3148    }
    3149
    3150    /**
    3151     * Gets a String version of the string builder, creating a new instance each time the method is called.
    3152     * <p>
    3153     * Note that unlike StringBuffer, the string version returned is independent of the string builder.
    3154     * </p>
    3155     *
    3156     * @return The builder as a String
    3157     */
    3158    @Override
    3159    public String toString() {
    3160        return new String(buffer, 0, size);
    3161    }
    3162
    3163    /**
    3164     * Gets a StringBuffer version of the string builder, creating a new instance each time the method is called.
    3165     *
    3166     * @return The builder as a StringBuffer
    3167     */
    3168    public StringBuffer toStringBuffer() {
    3169        return new StringBuffer(size).append(buffer, 0, size);
    3170    }
    3171
    3172    /**
    3173     * Gets a StringBuilder version of the string builder, creating a new instance each time the method is called.
    3174     *
    3175     * @return The builder as a StringBuilder
    3176     */
    3177    public StringBuilder toStringBuilder() {
    3178        return new StringBuilder(size).append(buffer, 0, size);
    3179    }
    3180
    3181    /**
    3182     * Trims the builder by removing characters less than or equal to a space from the beginning and end.
    3183     *
    3184     * @return this, to enable chaining
    3185     */
    3186    public TextStringBuilder trim() {
    3187        if (size == 0) {
    3188            return this;
    3189        }
    3190        int len = size;
    3191        final char[] buf = buffer;
    3192        int pos = 0;
    3193        while (pos < len && buf[pos] <= SPACE) {
    3194            pos++;
    3195        }
    3196        while (pos < len && buf[len - 1] <= SPACE) {
    3197            len--;
    3198        }
    3199        if (len < size) {
    3200            delete(len, size);
    3201        }
    3202        if (pos > 0) {
    3203            delete(0, pos);
    3204        }
    3205        return this;
    3206    }
    3207
    3208    /**
    3209     * Validates that an index is in the range {@code 0 <= index <= size}.
    3210     *
    3211     * @param index the index to test.
    3212     * @throws IndexOutOfBoundsException Thrown when the index is not the range {@code 0 <= index <= size}.
    3213     */
    3214    protected void validateIndex(final int index) {
    3215        if (index < 0 || index >= size) {
    3216            throw new StringIndexOutOfBoundsException(index);
    3217        }
    3218    }
    3219
    3220    /**
    3221     * Validates parameters defining a range of the builder.
    3222     *
    3223     * @param startIndex the start index, inclusive, must be valid
    3224     * @param endIndex the end index, exclusive, must be valid except that if too large it is treated as end of string
    3225     * @return A valid end index.
    3226     * @throws StringIndexOutOfBoundsException if the index is invalid
    3227     */
    3228    protected int validateRange(final int startIndex, int endIndex) {
    3229        if (startIndex < 0) {
    3230            throw new StringIndexOutOfBoundsException(startIndex);
    3231        }
    3232        if (endIndex > size) {
    3233            endIndex = size;
    3234        }
    3235        if (startIndex > endIndex) {
    3236            throw new StringIndexOutOfBoundsException("end < start");
    3237        }
    3238        return endIndex;
    3239    }
    3240
    3241}