    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 TextStringBuilder.this.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 >= TextStringBuilder.this.size()) {
    133                return -1;
    134            }
    135            if (pos + len > size()) {
    136                len = TextStringBuilder.this.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 < TextStringBuilder.this.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 > TextStringBuilder.this.size()) {
    159                n = TextStringBuilder.this.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(TextStringBuilder.this.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    /** The new line. */
    354    private String newLine;
    355
    356    /** The null text. */
    357    private String nullText;
    358
    359    /** Incremented when the buffer is reallocated. */
    360    private int reallocations;
    361
    362    /** Current size of the buffer. */
    363    private int size;
    364
    365    /**
    366     * Constructs an empty builder with an initial capacity of 32 characters.
    367     */
    368    public TextStringBuilder() {
    369        this(CAPACITY);
    370    }
    371
    372    /**
    373     * Constructs an instance from a reference to a character array.
    374     *
    375     * @param initialBuffer a reference to a character array, must not be null.
    376     * @param length The length of the subarray to be used; must be non-negative and no larger than
    377     *        {@code initialBuffer.length}. The new builder's size will be set to {@code length}.
    378     * @throws NullPointerException If {@code initialBuffer} is null.
    379     * @throws IllegalArgumentException if {@code length} is bad.
    380     */
    381    private TextStringBuilder(final char[] initialBuffer, final int length) {
    382        this.buffer = Objects.requireNonNull(initialBuffer, "initialBuffer");
    383        if (length < 0 || length > initialBuffer.length) {
    384            throw new IllegalArgumentException("initialBuffer.length=" + initialBuffer.length + ", length=" + length);
    385        }
    386        this.size = length;
    387    }
    388
    389    /**
    390     * Constructs an instance from a character sequence, allocating 32 extra characters for growth.
    391     *
    392     * @param seq the string to copy, null treated as blank string
    393     * @since 1.9
    394     */
    395    public TextStringBuilder(final CharSequence seq) {
    396        this(StringUtils.length(seq) + CAPACITY);
    397        if (seq != null) {
    398            append(seq);
    399        }
    400    }
    401
    402    /**
    403     * Constructs an instance with the specified initial capacity.
    404     *
    405     * @param initialCapacity the initial capacity, zero or less will be converted to 32
    406     */
    407    public TextStringBuilder(final int initialCapacity) {
    408        buffer = new char[initialCapacity <= 0 ? CAPACITY : initialCapacity];
    409    }
    410
    411    /**
    412     * Constructs an instance from a string, allocating 32 extra characters for growth.
    413     *
    414     * @param str the string to copy, null treated as blank string
    415     */
    416    public TextStringBuilder(final String str) {
    417        this(StringUtils.length(str) + CAPACITY);
    418        if (str != null) {
    419            append(str);
    420        }
    421    }
    422
    423    /**
    424     * Appends a boolean value to the string builder.
    425     *
    426     * @param value the value to append
    427     * @return this, to enable chaining
    428     */
    429    public TextStringBuilder append(final boolean value) {
    430        if (value) {
    431            ensureCapacityInternal(size + TRUE_STRING_SIZE);
    432            appendTrue(size);
    433        } else {
    434            ensureCapacityInternal(size + FALSE_STRING_SIZE);
    435            appendFalse(size);
    436        }
    437        return this;
    438    }
    439
    440    /**
    441     * Appends a char value to the string builder.
    442     *
    443     * @param ch the value to append
    444     * @return this, to enable chaining
    445     */
    446    @Override
    447    public TextStringBuilder append(final char ch) {
    448        final int len = length();
    449        ensureCapacityInternal(len + 1);
    450        buffer[size++] = ch;
    451        return this;
    452    }
    453
    454    /**
    455     * Appends a char array to the string builder. Appending null will call {@link #appendNull()}.
    456     *
    457     * @param chars the char array to append
    458     * @return this, to enable chaining
    459     */
    460    public TextStringBuilder append(final char[] chars) {
    461        if (chars == null) {
    462            return appendNull();
    463        }
    464        final int strLen = chars.length;
    465        if (strLen > 0) {
    466            final int len = length();
    467            ensureCapacityInternal(len + strLen);
    468            System.arraycopy(chars, 0, buffer, len, strLen);
    469            size += strLen;
    470        }
    471        return this;
    472    }
    473
    474    /**
    475     * Appends a char array to the string builder. Appending null will call {@link #appendNull()}.
    476     *
    477     * @param chars the char array to append
    478     * @param startIndex the start index, inclusive, must be valid
    479     * @param length the length to append, must be valid
    480     * @return this, to enable chaining
    481     * @throws StringIndexOutOfBoundsException if {@code startIndex} is not in the
    482     *  range {@code 0 <= startIndex <= chars.length}
    483     * @throws StringIndexOutOfBoundsException if {@code length < 0}
    484     * @throws StringIndexOutOfBoundsException if {@code startIndex + length > chars.length}
    485     */
    486    public TextStringBuilder append(final char[] chars, final int startIndex, final int length) {
    487        if (chars == null) {
    488            return appendNull();
    489        }
    490        if (startIndex < 0 || startIndex > chars.length) {
    491            throw new StringIndexOutOfBoundsException("Invalid startIndex: " + length);
    492        }
    493        if (length < 0 || startIndex + length > chars.length) {
    494            throw new StringIndexOutOfBoundsException("Invalid length: " + length);
    495        }
    496        if (length > 0) {
    497            final int len = length();
    498            ensureCapacityInternal(len + length);
    499            System.arraycopy(chars, startIndex, buffer, len, length);
    500            size += length;
    501        }
    502        return this;
    503    }
    504
    505    /**
    506     * Appends the contents of a char buffer to this string builder. Appending null will call {@link #appendNull()}.
    507     *
    508     * @param str the char buffer to append
    509     * @return this, to enable chaining
    510     */
    511    public TextStringBuilder append(final CharBuffer str) {
    512        return append(str, 0, StringUtils.length(str));
    513    }
    514
    515    /**
    516     * Appends the contents of a char buffer to this string builder. Appending null will call {@link #appendNull()}.
    517     *
    518     * @param buf the char buffer to append
    519     * @param startIndex the start index, inclusive, must be valid
    520     * @param length the length to append, must be valid
    521     * @return this, to enable chaining
    522     */
    523    public TextStringBuilder append(final CharBuffer buf, final int startIndex, final int length) {
    524        if (buf == null) {
    525            return appendNull();
    526        }
    527        if (buf.hasArray()) {
    528            final int totalLength = buf.remaining();
    529            if (startIndex < 0 || startIndex > totalLength) {
    530                throw new StringIndexOutOfBoundsException("startIndex must be valid");
    531            }
    532            if (length < 0 || startIndex + length > totalLength) {
    533                throw new StringIndexOutOfBoundsException("length must be valid");
    534            }
    535            final int len = length();
    536            ensureCapacityInternal(len + length);
    537            System.arraycopy(buf.array(), buf.arrayOffset() + buf.position() + startIndex, buffer, len, length);
    538            size += length;
    539        } else {
    540            append(buf.toString(), startIndex, length);
    541        }
    542        return this;
    543    }
    544
    545    /**
    546     * Appends a CharSequence to this string builder. Appending null will call {@link #appendNull()}.
    547     *
    548     * @param seq the CharSequence to append
    549     * @return this, to enable chaining
    550     */
    551    @Override
    552    public TextStringBuilder append(final CharSequence seq) {
    553        if (seq == null) {
    554            return appendNull();
    555        }
    556        if (seq instanceof TextStringBuilder) {
    557            return append((TextStringBuilder) seq);
    558        }
    559        if (seq instanceof StringBuilder) {
    560            return append((StringBuilder) seq);
    561        }
    562        if (seq instanceof StringBuffer) {
    563            return append((StringBuffer) seq);
    564        }
    565        if (seq instanceof CharBuffer) {
    566            return append((CharBuffer) seq);
    567        }
    568        return append(seq.toString());
    569    }
    570
    571    /**
    572     * Appends part of a CharSequence to this string builder. Appending null will call {@link #appendNull()}.
    573     *
    574     * @param seq the CharSequence to append
    575     * @param startIndex the start index, inclusive, must be valid
    576     * @param endIndex the end index, exclusive, must be valid
    577     * @return this, to enable chaining
    578     */
    579    @Override
    580    public TextStringBuilder append(final CharSequence seq, final int startIndex, final int endIndex) {
    581        if (seq == null) {
    582            return appendNull();
    583        }
    584        if (endIndex <= 0) {
    585            throw new StringIndexOutOfBoundsException("endIndex must be valid");
    586        }
    587        if (startIndex >= endIndex) {
    588            throw new StringIndexOutOfBoundsException("endIndex must be greater than startIndex");
    589        }
    590        return append(seq.toString(), startIndex, endIndex - startIndex);
    591    }
    592
    593    /**
    594     * Appends a double value to the string builder using {@code String.valueOf}.
    595     *
    596     * @param value the value to append
    597     * @return this, to enable chaining
    598     */
    599    public TextStringBuilder append(final double value) {
    600        return append(String.valueOf(value));
    601    }
    602
    603    /**
    604     * Appends a float value to the string builder using {@code String.valueOf}.
    605     *
    606     * @param value the value to append
    607     * @return this, to enable chaining
    608     */
    609    public TextStringBuilder append(final float value) {
    610        return append(String.valueOf(value));
    611    }
    612
    613    /**
    614     * Appends an int value to the string builder using {@code String.valueOf}.
    615     *
    616     * @param value the value to append
    617     * @return this, to enable chaining
    618     */
    619    public TextStringBuilder append(final int value) {
    620        return append(String.valueOf(value));
    621    }
    622
    623    /**
    624     * Appends a long value to the string builder using {@code String.valueOf}.
    625     *
    626     * @param value the value to append
    627     * @return this, to enable chaining
    628     */
    629    public TextStringBuilder append(final long value) {
    630        return append(String.valueOf(value));
    631    }
    632
    633    /**
    634     * Appends an object to this string builder. Appending null will call {@link #appendNull()}.
    635     *
    636     * @param obj the object to append
    637     * @return this, to enable chaining
    638     */
    639    public TextStringBuilder append(final Object obj) {
    640        if (obj == null) {
    641            return appendNull();
    642        }
    643        if (obj instanceof CharSequence) {
    644            return append((CharSequence) obj);
    645        }
    646        return append(obj.toString());
    647    }
    648
    649    /**
    650     * Appends a string to this string builder. Appending null will call {@link #appendNull()}.
    651     *
    652     * @param str the string to append
    653     * @return this, to enable chaining
    654     */
    655    public TextStringBuilder append(final String str) {
    656        return append(str, 0, StringUtils.length(str));
    657    }
    658
    659    /**
    660     * Appends part of a string to this string builder. Appending null will call {@link #appendNull()}.
    661     *
    662     * @param str the string to append
    663     * @param startIndex the start index, inclusive, must be valid
    664     * @param length the length to append, must be valid
    665     * @return this, to enable chaining
    666     * @throws StringIndexOutOfBoundsException if {@code startIndex} is not in the
    667     *  range {@code 0 <= startIndex <= str.length()}
    668     * @throws StringIndexOutOfBoundsException if {@code length < 0}
    669     * @throws StringIndexOutOfBoundsException if {@code startIndex + length > str.length()}
    670     */
    671    public TextStringBuilder append(final String str, final int startIndex, final int length) {
    672        if (str == null) {
    673            return appendNull();
    674        }
    675        if (startIndex < 0 || startIndex > str.length()) {
    676            throw new StringIndexOutOfBoundsException("startIndex must be valid");
    677        }
    678        if (length < 0 || startIndex + length > str.length()) {
    679            throw new StringIndexOutOfBoundsException("length must be valid");
    680        }
    681        if (length > 0) {
    682            final int len = length();
    683            ensureCapacityInternal(len + length);
    684            str.getChars(startIndex, startIndex + length, buffer, len);
    685            size += length;
    686        }
    687        return this;
    688    }
    689
    690    /**
    691     * Calls {@link String#format(String, Object...)} and appends the result.
    692     *
    693     * @param format the format string
    694     * @param objs the objects to use in the format string
    695     * @return {@code this} to enable chaining
    696     * @see String#format(String, Object...)
    697     */
    698    public TextStringBuilder append(final String format, final Object... objs) {
    699        return append(String.format(format, objs));
    700    }
    701
    702    /**
    703     * Appends a string buffer to this string builder. Appending null will call {@link #appendNull()}.
    704     *
    705     * @param str the string buffer to append
    706     * @return this, to enable chaining
    707     */
    708    public TextStringBuilder append(final StringBuffer str) {
    709        return append(str, 0, StringUtils.length(str));
    710    }
    711
    712    /**
    713     * Appends part of a string buffer to this string builder. Appending null will call {@link #appendNull()}.
    714     *
    715     * @param str the string to append
    716     * @param startIndex the start index, inclusive, must be valid
    717     * @param length the length to append, must be valid
    718     * @return this, to enable chaining
    719     */
    720    public TextStringBuilder append(final StringBuffer str, final int startIndex, final int length) {
    721        if (str == null) {
    722            return appendNull();
    723        }
    724        if (startIndex < 0 || startIndex > str.length()) {
    725            throw new StringIndexOutOfBoundsException("startIndex must be valid");
    726        }
    727        if (length < 0 || startIndex + length > str.length()) {
    728            throw new StringIndexOutOfBoundsException("length must be valid");
    729        }
    730        if (length > 0) {
    731            final int len = length();
    732            ensureCapacityInternal(len + length);
    733            str.getChars(startIndex, startIndex + length, buffer, len);
    734            size += length;
    735        }
    736        return this;
    737    }
    738
    739    /**
    740     * Appends a StringBuilder to this string builder. Appending null will call {@link #appendNull()}.
    741     *
    742     * @param str the StringBuilder to append
    743     * @return this, to enable chaining
    744     */
    745    public TextStringBuilder append(final StringBuilder str) {
    746        return append(str, 0, StringUtils.length(str));
    747    }
    748
    749    /**
    750     * Appends part of a StringBuilder to this string builder. Appending null will call {@link #appendNull()}.
    751     *
    752     * @param str the StringBuilder to append
    753     * @param startIndex the start index, inclusive, must be valid
    754     * @param length the length to append, must be valid
    755     * @return this, to enable chaining
    756     */
    757    public TextStringBuilder append(final StringBuilder str, final int startIndex, final int length) {
    758        if (str == null) {
    759            return appendNull();
    760        }
    761        if (startIndex < 0 || startIndex > str.length()) {
    762            throw new StringIndexOutOfBoundsException("startIndex must be valid");
    763        }
    764        if (length < 0 || startIndex + length > str.length()) {
    765            throw new StringIndexOutOfBoundsException("length must be valid");
    766        }
    767        if (length > 0) {
    768            final int len = length();
    769            ensureCapacityInternal(len + length);
    770            str.getChars(startIndex, startIndex + length, buffer, len);
    771            size += length;
    772        }
    773        return this;
    774    }
    775
    776    /**
    777     * Appends another string builder to this string builder. Appending null will call {@link #appendNull()}.
    778     *
    779     * @param str the string builder to append
    780     * @return this, to enable chaining
    781     */
    782    public TextStringBuilder append(final TextStringBuilder str) {
    783        return append(str, 0, StringUtils.length(str));
    784    }
    785
    786    /**
    787     * Appends part of a string builder to this string builder. Appending null will call {@link #appendNull()}.
    788     *
    789     * @param str the string to append
    790     * @param startIndex the start index, inclusive, must be valid
    791     * @param length the length to append, must be valid
    792     * @return this, to enable chaining
    793     */
    794    public TextStringBuilder append(final TextStringBuilder str, final int startIndex, final int length) {
    795        if (str == null) {
    796            return appendNull();
    797        }
    798        if (startIndex < 0 || startIndex > str.length()) {
    799            throw new StringIndexOutOfBoundsException("startIndex must be valid");
    800        }
    801        if (length < 0 || startIndex + length > str.length()) {
    802            throw new StringIndexOutOfBoundsException("length must be valid");
    803        }
    804        if (length > 0) {
    805            final int len = length();
    806            ensureCapacityInternal(len + length);
    807            str.getChars(startIndex, startIndex + length, buffer, len);
    808            size += length;
    809        }
    810        return this;
    811    }
    812
    813    /**
    814     * Appends each item in an iterable to the builder without any separators. Appending a null iterable will have no
    815     * effect. Each object is appended using {@link #append(Object)}.
    816     *
    817     * @param iterable the iterable to append
    818     * @return this, to enable chaining
    819     */
    820    public TextStringBuilder appendAll(final Iterable<?> iterable) {
    821        if (iterable != null) {
    822            iterable.forEach(this::append);
    823        }
    824        return this;
    825    }
    826
    827    /**
    828     * Appends each item in an iterator to the builder without any separators. Appending a null iterator will have no
    829     * effect. Each object is appended using {@link #append(Object)}.
    830     *
    831     * @param it the iterator to append
    832     * @return this, to enable chaining
    833     */
    834    public TextStringBuilder appendAll(final Iterator<?> it) {
    835        if (it != null) {
    836            it.forEachRemaining(this::append);
    837        }
    838        return this;
    839    }
    840
    841    /**
    842     * Appends each item in an array to the builder without any separators. Appending a null array will have no effect.
    843     * Each object is appended using {@link #append(Object)}.
    844     *
    845     * @param <T> the element type
    846     * @param array the array to append
    847     * @return this, to enable chaining
    848     */
    849    public <T> TextStringBuilder appendAll(@SuppressWarnings("unchecked") final T... array) {
    850        /*
    851         * @SuppressWarnings used to hide warning about vararg usage. We cannot use @SafeVarargs, since this method is
    852         * not final. Using @SuppressWarnings is fine, because it isn't inherited by subclasses, so each subclass must
    853         * vouch for itself whether its use of 'array' is safe.
    854         */
    855        if (array != null && array.length > 0) {
    856            for (final Object element : array) {
    857                append(element);
    858            }
    859        }
    860        return this;
    861    }
    862
    863    /** Appends {@code "false"}. */
    864    private void appendFalse(int index) {
    865        buffer[index++] = 'f';
    866        buffer[index++] = 'a';
    867        buffer[index++] = 'l';
    868        buffer[index++] = 's';
    869        buffer[index] = 'e';
    870        size += FALSE_STRING_SIZE;
    871    }
    872
    873    /**
    874     * Appends an object to the builder padding on the left to a fixed width. The {@code String.valueOf} of the
    875     * {@code int} value is used. If the formatted value is larger than the length, the left hand side is lost.
    876     *
    877     * @param value the value to append
    878     * @param width the fixed field width, zero or negative has no effect
    879     * @param padChar the pad character to use
    880     * @return this, to enable chaining
    881     */
    882    public TextStringBuilder appendFixedWidthPadLeft(final int value, final int width, final char padChar) {
    883        return appendFixedWidthPadLeft(String.valueOf(value), width, padChar);
    884    }
    885
    886    /**
    887     * Appends an object to the builder padding on the left to a fixed width. The {@code toString} of the object is
    888     * used. If the object is larger than the length, the left hand side is lost. If the object is null, the null text
    889     * value is used.
    890     *
    891     * @param obj the object to append, null uses null text
    892     * @param width the fixed field width, zero or negative has no effect
    893     * @param padChar the pad character to use
    894     * @return this, to enable chaining
    895     */
    896    public TextStringBuilder appendFixedWidthPadLeft(final Object obj, final int width, final char padChar) {
    897        if (width > 0) {
    898            ensureCapacityInternal(size + width);
    899            String str = obj == null ? getNullText() : obj.toString();
    900            if (str == null) {
    901                str = StringUtils.EMPTY;
    902            }
    903            final int strLen = str.length();
    904            if (strLen >= width) {
    905                str.getChars(strLen - width, strLen, buffer, size);
    906            } else {
    907                final int padLen = width - strLen;
    908                for (int i = 0; i < padLen; i++) {
    909                    buffer[size + i] = padChar;
    910                }
    911                str.getChars(0, strLen, buffer, size + padLen);
    912            }
    913            size += width;
    914        }
    915        return this;
    916    }
    917
    918    /**
    919     * Appends an object to the builder padding on the right to a fixed length. The {@code String.valueOf} of the
    920     * {@code int} value is used. If the object is larger than the length, the right hand side is lost.
    921     *
    922     * @param value the value to append
    923     * @param width the fixed field width, zero or negative has no effect
    924     * @param padChar the pad character to use
    925     * @return this, to enable chaining
    926     */
    927    public TextStringBuilder appendFixedWidthPadRight(final int value, final int width, final char padChar) {
    928        return appendFixedWidthPadRight(String.valueOf(value), width, padChar);
    929    }
    930
    931    /**
    932     * Appends an object to the builder padding on the right to a fixed length. The {@code toString} of the object is
    933     * used. If the object is larger than the length, the right hand side is lost. If the object is null, null text
    934     * value is used.
    935     *
    936     * @param obj the object to append, null uses null text
    937     * @param width the fixed field width, zero or negative has no effect
    938     * @param padChar the pad character to use
    939     * @return this, to enable chaining
    940     */
    941    public TextStringBuilder appendFixedWidthPadRight(final Object obj, final int width, final char padChar) {
    942        if (width > 0) {
    943            ensureCapacityInternal(size + width);
    944            String str = obj == null ? getNullText() : obj.toString();
    945            if (str == null) {
    946                str = StringUtils.EMPTY;
    947            }
    948            final int strLen = str.length();
    949            if (strLen >= width) {
    950                str.getChars(0, width, buffer, size);
    951            } else {
    952                final int padLen = width - strLen;
    953                str.getChars(0, strLen, buffer, size);
    954                for (int i = 0; i < padLen; i++) {
    955                    buffer[size + strLen + i] = padChar;
    956                }
    957            }
    958            size += width;
    959        }
    960        return this;
    961    }
    962
    963    /**
    964     * Appends a boolean value followed by a new line to the string builder.
    965     *
    966     * @param value the value to append
    967     * @return this, to enable chaining
    968     */
    969    public TextStringBuilder appendln(final boolean value) {
    970        return append(value).appendNewLine();
    971    }
    972
    973    /**
    974     * Appends a char value followed by a new line to the string builder.
    975     *
    976     * @param ch the value to append
    977     * @return this, to enable chaining
    978     */
    979    public TextStringBuilder appendln(final char ch) {
    980        return append(ch).appendNewLine();
    981    }
    982
    983    /**
    984     * Appends a char array followed by a new line to the string builder. Appending null will call
    985     * {@link #appendNull()}.
    986     *
    987     * @param chars the char array to append
    988     * @return this, to enable chaining
    989     */
    990    public TextStringBuilder appendln(final char[] chars) {
    991        return append(chars).appendNewLine();
    992    }
    993
    994    /**
    995     * Appends a char array followed by a new line to the string builder. Appending null will call
    996     * {@link #appendNull()}.
    997     *
    998     * @param chars the char array to append
    999     * @param startIndex the start index, inclusive, must be valid
    1000     * @param length the length to append, must be valid
    1001     * @return this, to enable chaining
    1002     */
    1003    public TextStringBuilder appendln(final char[] chars, final int startIndex, final int length) {
    1004        return append(chars, startIndex, length).appendNewLine();
    1005    }
    1006
    1007    /**
    1008     * Appends a double value followed by a new line to the string builder using {@code String.valueOf}.
    1009     *
    1010     * @param value the value to append
    1011     * @return this, to enable chaining
    1012     */
    1013    public TextStringBuilder appendln(final double value) {
    1014        return append(value).appendNewLine();
    1015    }
    1016
    1017    /**
    1018     * Appends a float value followed by a new line to the string builder using {@code String.valueOf}.
    1019     *
    1020     * @param value the value to append
    1021     * @return this, to enable chaining
    1022     */
    1023    public TextStringBuilder appendln(final float value) {
    1024        return append(value).appendNewLine();
    1025    }
    1026
    1027    /**
    1028     * Appends an int value followed by a new line to the string builder using {@code String.valueOf}.
    1029     *
    1030     * @param value the value to append
    1031     * @return this, to enable chaining
    1032     */
    1033    public TextStringBuilder appendln(final int value) {
    1034        return append(value).appendNewLine();
    1035    }
    1036
    1037    /**
    1038     * Appends a long value followed by a new line to the string builder using {@code String.valueOf}.
    1039     *
    1040     * @param value the value to append
    1041     * @return this, to enable chaining
    1042     */
    1043    public TextStringBuilder appendln(final long value) {
    1044        return append(value).appendNewLine();
    1045    }
    1046
    1047    /**
    1048     * Appends an object followed by a new line to this string builder. Appending null will call {@link #appendNull()}.
    1049     *
    1050     * @param obj the object to append
    1051     * @return this, to enable chaining
    1052     */
    1053    public TextStringBuilder appendln(final Object obj) {
    1054        return append(obj).appendNewLine();
    1055    }
    1056
    1057    /**
    1058     * Appends a string followed by a new line to this string builder. Appending null will call {@link #appendNull()}.
    1059     *
    1060     * @param str the string to append
    1061     * @return this, to enable chaining
    1062     */
    1063    public TextStringBuilder appendln(final String str) {
    1064        return append(str).appendNewLine();
    1065    }
    1066
    1067    /**
    1068     * Appends part of a string followed by a new line to this string builder. Appending null will call
    1069     * {@link #appendNull()}.
    1070     *
    1071     * @param str the string to append
    1072     * @param startIndex the start index, inclusive, must be valid
    1073     * @param length the length to append, must be valid
    1074     * @return this, to enable chaining
    1075     */
    1076    public TextStringBuilder appendln(final String str, final int startIndex, final int length) {
    1077        return append(str, startIndex, length).appendNewLine();
    1078    }
    1079
    1080    /**
    1081     * Calls {@link String#format(String, Object...)} and appends the result.
    1082     *
    1083     * @param format the format string
    1084     * @param objs the objects to use in the format string
    1085     * @return {@code this} to enable chaining
    1086     * @see String#format(String, Object...)
    1087     */
    1088    public TextStringBuilder appendln(final String format, final Object... objs) {
    1089        return append(format, objs).appendNewLine();
    1090    }
    1091
    1092    /**
    1093     * Appends a string buffer followed by a new line to this string builder. Appending null will call
    1094     * {@link #appendNull()}.
    1095     *
    1096     * @param str the string buffer to append
    1097     * @return this, to enable chaining
    1098     */
    1099    public TextStringBuilder appendln(final StringBuffer str) {
    1100        return append(str).appendNewLine();
    1101    }
    1102
    1103    /**
    1104     * Appends part of a string buffer followed by a new line to this string builder. Appending null will call
    1105     * {@link #appendNull()}.
    1106     *
    1107     * @param str the string to append
    1108     * @param startIndex the start index, inclusive, must be valid
    1109     * @param length the length to append, must be valid
    1110     * @return this, to enable chaining
    1111     */
    1112    public TextStringBuilder appendln(final StringBuffer str, final int startIndex, final int length) {
    1113        return append(str, startIndex, length).appendNewLine();
    1114    }
    1115
    1116    /**
    1117     * Appends a string builder followed by a new line to this string builder. Appending null will call
    1118     * {@link #appendNull()}.
    1119     *
    1120     * @param str the string builder to append
    1121     * @return this, to enable chaining
    1122     */
    1123    public TextStringBuilder appendln(final StringBuilder str) {
    1124        return append(str).appendNewLine();
    1125    }
    1126
    1127    /**
    1128     * Appends part of a string builder followed by a new line to this string builder. Appending null will call
    1129     * {@link #appendNull()}.
    1130     *
    1131     * @param str the string builder to append
    1132     * @param startIndex the start index, inclusive, must be valid
    1133     * @param length the length to append, must be valid
    1134     * @return this, to enable chaining
    1135     */
    1136    public TextStringBuilder appendln(final StringBuilder str, final int startIndex, final int length) {
    1137        return append(str, startIndex, length).appendNewLine();
    1138    }
    1139
    1140    /**
    1141     * Appends another string builder followed by a new line to this string builder. Appending null will call
    1142     * {@link #appendNull()}.
    1143     *
    1144     * @param str the string builder to append
    1145     * @return this, to enable chaining
    1146     */
    1147    public TextStringBuilder appendln(final TextStringBuilder str) {
    1148        return append(str).appendNewLine();
    1149    }
    1150
    1151    /**
    1152     * Appends part of a string builder followed by a new line to this string builder. Appending null will call
    1153     * {@link #appendNull()}.
    1154     *
    1155     * @param str the string to append
    1156     * @param startIndex the start index, inclusive, must be valid
    1157     * @param length the length to append, must be valid
    1158     * @return this, to enable chaining
    1159     */
    1160    public TextStringBuilder appendln(final TextStringBuilder str, final int startIndex, final int length) {
    1161        return append(str, startIndex, length).appendNewLine();
    1162    }
    1163
    1164    /**
    1165     * Appends the new line string to this string builder.
    1166     * <p>
    1167     * The new line string can be altered using {@link #setNewLineText(String)}. This might be used to force the output
    1168     * to always use UNIX line endings even when on Windows.
    1169     * </p>
    1170     *
    1171     * @return this, to enable chaining
    1172     */
    1173    public TextStringBuilder appendNewLine() {
    1174        if (newLine == null) {
    1175            append(System.lineSeparator());
    1176            return this;
    1177        }
    1178        return append(newLine);
    1179    }
    1180
    1181    /**
    1182     * Appends the text representing {@code null} to this string builder.
    1183     *
    1184     * @return this, to enable chaining
    1185     */
    1186    public TextStringBuilder appendNull() {
    1187        if (nullText == null) {
    1188            return this;
    1189        }
    1190        return append(nullText);
    1191    }
    1192
    1193    /**
    1194     * Appends the pad character to the builder the specified number of times.
    1195     *
    1196     * @param length the length to append, negative means no append
    1197     * @param padChar the character to append
    1198     * @return this, to enable chaining
    1199     */
    1200    public TextStringBuilder appendPadding(final int length, final char padChar) {
    1201        if (length >= 0) {
    1202            ensureCapacityInternal(size + length);
    1203            for (int i = 0; i < length; i++) {
    1204                buffer[size++] = padChar;
    1205            }
    1206        }
    1207        return this;
    1208    }
    1209
    1210    /**
    1211     * Appends a separator if the builder is currently non-empty. The separator is appended using {@link #append(char)}.
    1212     * <p>
    1213     * This method is useful for adding a separator each time around the loop except the first.
    1214     * </p>
    1215     *
    1216     * <pre>
    1217     * for (Iterator it = list.iterator(); it.hasNext();) {
    1218     *     appendSeparator(',');
    1219     *     append(it.next());
    1220     * }
    1221     * </pre>
    1222     *
    1223     * <p>
    1224     * Note that for this simple example, you should use {@link #appendWithSeparators(Iterable, String)}.
    1225     * </p>
    1226     *
    1227     * @param separator the separator to use
    1228     * @return this, to enable chaining
    1229     */
    1230    public TextStringBuilder appendSeparator(final char separator) {
    1231        if (isNotEmpty()) {
    1232            append(separator);
    1233        }
    1234        return this;
    1235    }
    1236
    1237    /**
    1238     * Appends one of both separators to the builder If the builder is currently empty it will append the
    1239     * defaultIfEmpty-separator Otherwise it will append the standard-separator
    1240     *
    1241     * The separator is appended using {@link #append(char)}.
    1242     *
    1243     * @param standard the separator if builder is not empty
    1244     * @param defaultIfEmpty the separator if builder is empty
    1245     * @return this, to enable chaining
    1246     */
    1247    public TextStringBuilder appendSeparator(final char standard, final char defaultIfEmpty) {
    1248        if (isEmpty()) {
    1249            append(defaultIfEmpty);
    1250        } else {
    1251            append(standard);
    1252        }
    1253        return this;
    1254    }
    1255
    1256    /**
    1257     * Appends a separator to the builder if the loop index is greater than zero. The separator is appended using
    1258     * {@link #append(char)}.
    1259     * <p>
    1260     * This method is useful for adding a separator each time around the loop except the first.
    1261     * </p>
    1262     *
    1263     * <pre>
    1264     * for (int i = 0; i &lt; list.size(); i++) {
    1265     *     appendSeparator(",", i);
    1266     *     append(list.get(i));
    1267     * }
    1268     * </pre>
    1269     *
    1270     * <p>
    1271     * Note that for this simple example, you should use {@link #appendWithSeparators(Iterable, String)}.
    1272     * </p>
    1273     *
    1274     * @param separator the separator to use
    1275     * @param loopIndex the loop index
    1276     * @return this, to enable chaining
    1277     */
    1278    public TextStringBuilder appendSeparator(final char separator, final int loopIndex) {
    1279        if (loopIndex > 0) {
    1280            append(separator);
    1281        }
    1282        return this;
    1283    }
    1284
    1285    /**
    1286     * Appends a separator if the builder is currently non-empty. Appending a null separator will have no effect. The
    1287     * separator is appended using {@link #append(String)}.
    1288     * <p>
    1289     * This method is useful for adding a separator each time around the loop except the first.
    1290     * </p>
    1291     *
    1292     * <pre>
    1293     * for (Iterator it = list.iterator(); it.hasNext();) {
    1294     *     appendSeparator(",");
    1295     *     append(it.next());
    1296     * }
    1297     * </pre>
    1298     *
    1299     * <p>
    1300     * Note that for this simple example, you should use {@link #appendWithSeparators(Iterable, String)}.
    1301     * </p>
    1302     *
    1303     * @param separator the separator to use, null means no separator
    1304     * @return this, to enable chaining
    1305     */
    1306    public TextStringBuilder appendSeparator(final String separator) {
    1307        return appendSeparator(separator, null);
    1308    }
    1309
    1310    /**
    1311     * Appends a separator to the builder if the loop index is greater than zero. Appending a null separator will have
    1312     * no effect. The separator is appended using {@link #append(String)}.
    1313     * <p>
    1314     * This method is useful for adding a separator each time around the loop except the first.
    1315     * </p>
    1316     *
    1317     * <pre>
    1318     * for (int i = 0; i &lt; list.size(); i++) {
    1319     *     appendSeparator(",", i);
    1320     *     append(list.get(i));
    1321     * }
    1322     * </pre>
    1323     *
    1324     * <p>
    1325     * Note that for this simple example, you should use {@link #appendWithSeparators(Iterable, String)}.
    1326     * </p>
    1327     *
    1328     * @param separator the separator to use, null means no separator
    1329     * @param loopIndex the loop index
    1330     * @return this, to enable chaining
    1331     */
    1332    public TextStringBuilder appendSeparator(final String separator, final int loopIndex) {
    1333        if (separator != null && loopIndex > 0) {
    1334            append(separator);
    1335        }
    1336        return this;
    1337    }
    1338
    1339    /**
    1340     * Appends one of both separators to the StrBuilder. If the builder is currently empty, it will append the
    1341     * defaultIfEmpty-separator, otherwise it will append the standard-separator.
    1342     * <p>
    1343     * Appending a null separator will have no effect. The separator is appended using {@link #append(String)}.
    1344     * </p>
    1345     * <p>
    1346     * This method is for example useful for constructing queries
    1347     * </p>
    1348     *
    1349     * <pre>
    1350     * StrBuilder whereClause = new StrBuilder();
    1351     * if (searchCommand.getPriority() != null) {
    1352     *  whereClause.appendSeparator(" and", " where");
    1353     *  whereClause.append(" priority = ?")
    1354     * }
    1355     * if (searchCommand.getComponent() != null) {
    1356     *  whereClause.appendSeparator(" and", " where");
    1357     *  whereClause.append(" component = ?")
    1358     * }
    1359     * selectClause.append(whereClause)
    1360     * </pre>
    1361     *
    1362     * @param standard the separator if builder is not empty, null means no separator
    1363     * @param defaultIfEmpty the separator if builder is empty, null means no separator
    1364     * @return this, to enable chaining
    1365     */
    1366    public TextStringBuilder appendSeparator(final String standard, final String defaultIfEmpty) {
    1367        final String str = isEmpty() ? defaultIfEmpty : standard;
    1368        if (str != null) {
    1369            append(str);
    1370        }
    1371        return this;
    1372    }
    1373
    1374    /**
    1375     * Appends current contents of this {@code StrBuilder} to the provided {@link Appendable}.
    1376     * <p>
    1377     * This method tries to avoid doing any extra copies of contents.
    1378     * </p>
    1379     *
    1380     * @param appendable the appendable to append data to
    1381     * @throws IOException if an I/O error occurs.
    1382     *
    1383     * @see #readFrom(Readable)
    1384     */
    1385    public void appendTo(final Appendable appendable) throws IOException {
    1386        if (appendable instanceof Writer) {
    1387            ((Writer) appendable).write(buffer, 0, size);
    1388        } else if (appendable instanceof StringBuilder) {
    1389            ((StringBuilder) appendable).append(buffer, 0, size);
    1390        } else if (appendable instanceof StringBuffer) {
    1391            ((StringBuffer) appendable).append(buffer, 0, size);
    1392        } else if (appendable instanceof CharBuffer) {
    1393            ((CharBuffer) appendable).put(buffer, 0, size);
    1394        } else {
    1395            appendable.append(this);
    1396        }
    1397    }
    1398
    1399    /** Appends {@code "true"}. */
    1400    private void appendTrue(int index) {
    1401        buffer[index++] = 't';
    1402        buffer[index++] = 'r';
    1403        buffer[index++] = 'u';
    1404        buffer[index] = 'e';
    1405        size += TRUE_STRING_SIZE;
    1406    }
    1407
    1408    /**
    1409     * Appends an iterable placing separators between each value, but not before the first or after the last. Appending
    1410     * a null iterable will have no effect. Each object is appended using {@link #append(Object)}.
    1411     *
    1412     * @param iterable the iterable to append
    1413     * @param separator the separator to use, null means no separator
    1414     * @return this, to enable chaining
    1415     */
    1416    public TextStringBuilder appendWithSeparators(final Iterable<?> iterable, final String separator) {
    1417        if (iterable != null) {
    1418            appendWithSeparators(iterable.iterator(), separator);
    1419        }
    1420        return this;
    1421    }
    1422
    1423    /**
    1424     * Appends an iterator placing separators between each value, but not before the first or after the last. Appending
    1425     * a null iterator will have no effect. Each object is appended using {@link #append(Object)}.
    1426     *
    1427     * @param it the iterator to append
    1428     * @param separator the separator to use, null means no separator
    1429     * @return this, to enable chaining
    1430     */
    1431    public TextStringBuilder appendWithSeparators(final Iterator<?> it, final String separator) {
    1432        if (it != null) {
    1433            final String sep = Objects.toString(separator, StringUtils.EMPTY);
    1434            while (it.hasNext()) {
    1435                append(it.next());
    1436                if (it.hasNext()) {
    1437                    append(sep);
    1438                }
    1439            }
    1440        }
    1441        return this;
    1442    }
    1443
    1444    /**
    1445     * Appends an array placing separators between each value, but not before the first or after the last. Appending a
    1446     * null array will have no effect. Each object is appended using {@link #append(Object)}.
    1447     *
    1448     * @param array the array to append
    1449     * @param separator the separator to use, null means no separator
    1450     * @return this, to enable chaining
    1451     */
    1452    public TextStringBuilder appendWithSeparators(final Object[] array, final String separator) {
    1453        if (array != null && array.length > 0) {
    1454            final String sep = Objects.toString(separator, StringUtils.EMPTY);
    1455            append(array[0]);
    1456            for (int i = 1; i < array.length; i++) {
    1457                append(sep);
    1458                append(array[i]);
    1459            }
    1460        }
    1461        return this;
    1462    }
    1463
    1464    /**
    1465     * Gets the contents of this builder as a Reader.
    1466     * <p>
    1467     * This method allows the contents of the builder to be read using any standard method that expects a Reader.
    1468     * </p>
    1469     * <p>
    1470     * To use, simply create a {@code StrBuilder}, populate it with data, call {@code asReader}, and then read away.
    1471     * </p>
    1472     * <p>
    1473     * The internal character array is shared between the builder and the reader. This allows you to append to the
    1474     * builder after creating the reader, and the changes will be picked up. Note however, that no synchronization
    1475     * occurs, so you must perform all operations with the builder and the reader in one thread.
    1476     * </p>
    1477     * <p>
    1478     * The returned reader supports marking, and ignores the flush method.
    1479     * </p>
    1480     *
    1481     * @return a reader that reads from this builder
    1482     */
    1483    public Reader asReader() {
    1484        return new TextStringBuilderReader();
    1485    }
    1486
    1487    /**
    1488     * Creates a tokenizer that can tokenize the contents of this builder.
    1489     * <p>
    1490     * This method allows the contents of this builder to be tokenized. The tokenizer will be setup by default to
    1491     * tokenize on space, tab, newline and form feed (as per StringTokenizer). These values can be changed on the
    1492     * tokenizer class, before retrieving the tokens.
    1493     * </p>
    1494     * <p>
    1495     * The returned tokenizer is linked to this builder. You may intermix calls to the builder and tokenizer within
    1496     * certain limits, however there is no synchronization. Once the tokenizer has been used once, it must be
    1497     * {@link StringTokenizer#reset() reset} to pickup the latest changes in the builder. For example:
    1498     * </p>
    1499     *
    1500     * <pre>
    1501     * StrBuilder b = new StrBuilder();
    1502     * b.append("a b ");
    1503     * StrTokenizer t = b.asTokenizer();
    1504     * String[] tokens1 = t.getTokenArray(); // returns a,b
    1505     * b.append("c d ");
    1506     * String[] tokens2 = t.getTokenArray(); // returns a,b (c and d ignored)
    1507     * t.reset(); // reset causes builder changes to be picked up
    1508     * String[] tokens3 = t.getTokenArray(); // returns a,b,c,d
    1509     * </pre>
    1510     *
    1511     * <p>
    1512     * In addition to simply intermixing appends and tokenization, you can also call the set methods on the tokenizer to
    1513     * alter how it tokenizes. Just remember to call reset when you want to pickup builder changes.
    1514     * </p>
    1515     * <p>
    1516     * Calling {@link StringTokenizer#reset(String)} or {@link StringTokenizer#reset(char[])} with a non-null value will
    1517     * break the link with the builder.
    1518     * </p>
    1519     *
    1520     * @return a tokenizer that is linked to this builder
    1521     */
    1522    public StringTokenizer asTokenizer() {
    1523        return new TextStringBuilderTokenizer();
    1524    }
    1525
    1526    /**
    1527     * Gets this builder as a Writer that can be written to.
    1528     * <p>
    1529     * This method allows you to populate the contents of the builder using any standard method that takes a Writer.
    1530     * </p>
    1531     * <p>
    1532     * To use, simply create a {@code StrBuilder}, call {@code asWriter}, and populate away. The data is available at
    1533     * any time using the methods of the {@code StrBuilder}.
    1534     * </p>
    1535     * <p>
    1536     * The internal character array is shared between the builder and the writer. This allows you to intermix calls that
    1537     * append to the builder and write using the writer and the changes will be occur correctly. Note however, that no
    1538     * synchronization occurs, so you must perform all operations with the builder and the writer in one thread.
    1539     * </p>
    1540     * <p>
    1541     * The returned writer ignores the close and flush methods.
    1542     * </p>
    1543     *
    1544     * @return a writer that populates this builder
    1545     */
    1546    public Writer asWriter() {
    1547        return new TextStringBuilderWriter();
    1548    }
    1549
    1550    /**
    1551     * Converts this instance to a String.
    1552     *
    1553     * @return This instance as a String
    1554     * @see #toString()
    1555     * @deprecated Use {@link #get()}.
    1556     */
    1557    @Deprecated
    1558    @Override
    1559    public String build() {
    1560        return toString();
    1561    }
    1562
    1563    /**
    1564     * Gets the current size of the internal character array buffer.
    1565     *
    1566     * @return The capacity
    1567     */
    1568    public int capacity() {
    1569        return buffer.length;
    1570    }
    1571
    1572    /**
    1573     * Gets the character at the specified index.
    1574     *
    1575     * @see #setCharAt(int, char)
    1576     * @see #deleteCharAt(int)
    1577     * @param index the index to retrieve, must be valid
    1578     * @return The character at the index
    1579     * @throws IndexOutOfBoundsException if the index is invalid
    1580     */
    1581    @Override
    1582    public char charAt(final int index) {
    1583        validateIndex(index);
    1584        return buffer[index];
    1585    }
    1586
    1587    /**
    1588     * Clears the string builder (convenience Collections API style method).
    1589     * <p>
    1590     * This method does not reduce the size of the internal character buffer. To do that, call {@code clear()} followed
    1591     * by {@link #minimizeCapacity()}.
    1592     * </p>
    1593     * <p>
    1594     * This method is the same as {@link #setLength(int)} called with zero and is provided to match the API of
    1595     * Collections.
    1596     * </p>
    1597     *
    1598     * @return this, to enable chaining
    1599     */
    1600    public TextStringBuilder clear() {
    1601        size = 0;
    1602        return this;
    1603    }
    1604
    1605    /**
    1606     * Tests if the string builder contains the specified char.
    1607     *
    1608     * @param ch the character to find
    1609     * @return true if the builder contains the character
    1610     */
    1611    public boolean contains(final char ch) {
    1612        final char[] thisBuf = buffer;
    1613        for (int i = 0; i < this.size; i++) {
    1614            if (thisBuf[i] == ch) {
    1615                return true;
    1616            }
    1617        }
    1618        return false;
    1619    }
    1620
    1621    /**
    1622     * Tests if the string builder contains the specified string.
    1623     *
    1624     * @param str the string to find
    1625     * @return true if the builder contains the string
    1626     */
    1627    public boolean contains(final String str) {
    1628        return indexOf(str, 0) >= 0;
    1629    }
    1630
    1631    /**
    1632     * Tests if the string builder contains a string matched using the specified matcher.
    1633     * <p>
    1634     * Matchers can be used to perform advanced searching behavior. For example you could write a matcher to search for
    1635     * the character 'a' followed by a number.
    1636     * </p>
    1637     *
    1638     * @param matcher the matcher to use, null returns -1
    1639     * @return true if the matcher finds a match in the builder
    1640     */
    1641    public boolean contains(final StringMatcher matcher) {
    1642        return indexOf(matcher, 0) >= 0;
    1643    }
    1644
    1645    /**
    1646     * Deletes the characters between the two specified indices.
    1647     *
    1648     * @param startIndex the start index, inclusive, must be valid
    1649     * @param endIndex the end index, exclusive, must be valid except that if too large it is treated as end of string
    1650     * @return this, to enable chaining
    1651     * @throws IndexOutOfBoundsException if the index is invalid
    1652     */
    1653    public TextStringBuilder delete(final int startIndex, final int endIndex) {
    1654        final int actualEndIndex = validateRange(startIndex, endIndex);
    1655        final int len = actualEndIndex - startIndex;
    1656        if (len > 0) {
    1657            deleteImpl(startIndex, actualEndIndex, len);
    1658        }
    1659        return this;
    1660    }
    1661
    1662    /**
    1663     * Deletes the character wherever it occurs in the builder.
    1664     *
    1665     * @param ch the character to delete
    1666     * @return this, to enable chaining
    1667     */
    1668    public TextStringBuilder deleteAll(final char ch) {
    1669        for (int i = 0; i < size; i++) {
    1670            if (buffer[i] == ch) {
    1671                final int start = i;
    1672                while (++i < size) {
    1673                    if (buffer[i] != ch) {
    1674                        break;
    1675                    }
    1676                }
    1677                final int len = i - start;
    1678                deleteImpl(start, i, len);
    1679                i -= len;
    1680            }
    1681        }
    1682        return this;
    1683    }
    1684
    1685    /**
    1686     * Deletes the string wherever it occurs in the builder.
    1687     *
    1688     * @param str the string to delete, null causes no action
    1689     * @return this, to enable chaining
    1690     */
    1691    public TextStringBuilder deleteAll(final String str) {
    1692        final int len = str == null ? 0 : str.length();
    1693        if (len > 0) {
    1694            int index = indexOf(str, 0);
    1695            while (index >= 0) {
    1696                deleteImpl(index, index + len, len);
    1697                index = indexOf(str, index);
    1698            }
    1699        }
    1700        return this;
    1701    }
    1702
    1703    /**
    1704     * Deletes all parts of the builder that the matcher matches.
    1705     * <p>
    1706     * Matchers can be used to perform advanced deletion behavior. For example you could write a matcher to delete all
    1707     * occurrences where the character 'a' is followed by a number.
    1708     * </p>
    1709     *
    1710     * @param matcher the matcher to use to find the deletion, null causes no action
    1711     * @return this, to enable chaining
    1712     */
    1713    public TextStringBuilder deleteAll(final StringMatcher matcher) {
    1714        return replace(matcher, null, 0, size, -1);
    1715    }
    1716
    1717    /**
    1718     * Deletes the character at the specified index.
    1719     *
    1720     * @see #charAt(int)
    1721     * @see #setCharAt(int, char)
    1722     * @param index the index to delete
    1723     * @return this, to enable chaining
    1724     * @throws IndexOutOfBoundsException if the index is invalid
    1725     */
    1726    public TextStringBuilder deleteCharAt(final int index) {
    1727        validateIndex(index);
    1728        deleteImpl(index, index + 1, 1);
    1729        return this;
    1730    }
    1731
    1732    /**
    1733     * Deletes the character wherever it occurs in the builder.
    1734     *
    1735     * @param ch the character to delete
    1736     * @return this, to enable chaining
    1737     */
    1738    public TextStringBuilder deleteFirst(final char ch) {
    1739        for (int i = 0; i < size; i++) {
    1740            if (buffer[i] == ch) {
    1741                deleteImpl(i, i + 1, 1);
    1742                break;
    1743            }
    1744        }
    1745        return this;
    1746    }
    1747
    1748    /**
    1749     * Deletes the string wherever it occurs in the builder.
    1750     *
    1751     * @param str the string to delete, null causes no action
    1752     * @return this, to enable chaining
    1753     */
    1754    public TextStringBuilder deleteFirst(final String str) {
    1755        final int len = str == null ? 0 : str.length();
    1756        if (len > 0) {
    1757            final int index = indexOf(str, 0);
    1758            if (index >= 0) {
    1759                deleteImpl(index, index + len, len);
    1760            }
    1761        }
    1762        return this;
    1763    }
    1764
    1765    /**
    1766     * Deletes the first match within the builder using the specified matcher.
    1767     * <p>
    1768     * Matchers can be used to perform advanced deletion behavior. For example you could write a matcher to delete where
    1769     * the character 'a' is followed by a number.
    1770     * </p>
    1771     *
    1772     * @param matcher the matcher to use to find the deletion, null causes no action
    1773     * @return this, to enable chaining
    1774     */
    1775    public TextStringBuilder deleteFirst(final StringMatcher matcher) {
    1776        return replace(matcher, null, 0, size, 1);
    1777    }
    1778
    1779    /**
    1780     * Internal method to delete a range without validation.
    1781     *
    1782     * @param startIndex the start index, must be valid
    1783     * @param endIndex the end index (exclusive), must be valid
    1784     * @param len the length, must be valid
    1785     * @throws IndexOutOfBoundsException if any index is invalid
    1786     */
    1787    private void deleteImpl(final int startIndex, final int endIndex, final int len) {
    1788        System.arraycopy(buffer, endIndex, buffer, startIndex, size - endIndex);
    1789        size -= len;
    1790    }
    1791
    1792    /**
    1793     * Gets the character at the specified index before deleting it.
    1794     *
    1795     * @see #charAt(int)
    1796     * @see #deleteCharAt(int)
    1797     * @param index the index to retrieve, must be valid
    1798     * @return The character at the index
    1799     * @throws IndexOutOfBoundsException if the index is invalid
    1800     * @since 1.9
    1801     */
    1802    public char drainChar(final int index) {
    1803        validateIndex(index);
    1804        final char c = buffer[index];
    1805        deleteCharAt(index);
    1806        return c;
    1807    }
    1808
    1809    /**
    1810     * Drains (copies, then deletes) this character sequence into the specified array. This is equivalent to copying the
    1811     * characters from this sequence into the target and then deleting those character from this sequence.
    1812     *
    1813     * @param startIndex first index to copy, inclusive.
    1814     * @param endIndex last index to copy, exclusive.
    1815     * @param target the target array, must not be {@code null}.
    1816     * @param targetIndex the index to start copying in the target.
    1817     * @return How many characters where copied (then deleted). If this builder is empty, return {@code 0}.
    1818     * @since 1.9
    1819     */
    1820    public int drainChars(final int startIndex, final int endIndex, final char[] target, final int targetIndex) {
    1821        final int length = endIndex - startIndex;
    1822        if (isEmpty() || length == 0 || target.length == 0) {
    1823            return 0;
    1824        }
    1825        final int actualLen = Math.min(Math.min(size, length), target.length - targetIndex);
    1826        getChars(startIndex, actualLen, target, targetIndex);
    1827        delete(startIndex, actualLen);
    1828        return actualLen;
    1829    }
    1830
    1831    /**
    1832     * Checks whether this builder ends with the specified string.
    1833     * <p>
    1834     * Note that this method handles null input quietly, unlike String.
    1835     * </p>
    1836     *
    1837     * @param str the string to search for, null returns false
    1838     * @return true if the builder ends with the string
    1839     */
    1840    public boolean endsWith(final String str) {
    1841        if (str == null) {
    1842            return false;
    1843        }
    1844        final int len = str.length();
    1845        if (len == 0) {
    1846            return true;
    1847        }
    1848        if (len > size) {
    1849            return false;
    1850        }
    1851        int pos = size - len;
    1852        for (int i = 0; i < len; i++, pos++) {
    1853            if (buffer[pos] != str.charAt(i)) {
    1854                return false;
    1855            }
    1856        }
    1857        return true;
    1858    }
    1859
    1860    /**
    1861     * Tests the capacity and ensures that it is at least the size specified.
    1862     *
    1863     * <p>
    1864     * Note: This method can be used to minimise memory reallocations during
    1865     * repeated addition of values by pre-allocating the character buffer.
    1866     * The method ignores a negative {@code capacity} argument.
    1867     * </p>
    1868     *
    1869     * @param capacity the capacity to ensure
    1870     * @return this, to enable chaining
    1871     * @throws OutOfMemoryError if the capacity cannot be allocated
    1872     */
    1873    public TextStringBuilder ensureCapacity(final int capacity) {
    1874        if (capacity > 0) {
    1875            ensureCapacityInternal(capacity);
    1876        }
    1877        return this;
    1878    }
    1879
    1880    /**
    1881     * Ensures that the buffer is at least the size specified. The {@code capacity} argument
    1882     * is treated as an unsigned integer.
    1883     *
    1884     * <p>
    1885     * This method will raise an {@link OutOfMemoryError} if the capacity is too large
    1886     * for an array, or cannot be allocated.
    1887     * </p>
    1888     *
    1889     * @param capacity the capacity to ensure
    1890     * @throws OutOfMemoryError if the capacity cannot be allocated
    1891     */
    1892    private void ensureCapacityInternal(final int capacity) {
    1893        // Check for overflow of the current buffer.
    1894        // Assumes capacity is an unsigned integer up to Integer.MAX_VALUE * 2
    1895        // (the largest possible addition of two maximum length arrays).
    1896        if (capacity - buffer.length > 0) {
    1897            resizeBuffer(capacity);
    1898        }
    1899    }
    1900
    1901    /**
    1902     * Tests the contents of this builder against another to see if they contain the same character content.
    1903     *
    1904     * @param obj the object to check, null returns false
    1905     * @return true if the builders contain the same characters in the same order
    1906     */
    1907    @Override
    1908    public boolean equals(final Object obj) {
    1909        return obj instanceof TextStringBuilder && equals((TextStringBuilder) obj);
    1910    }
    1911
    1912    /**
    1913     * Tests the contents of this builder against another to see if they contain the same character content.
    1914     *
    1915     * @param other the object to check, null returns false
    1916     * @return true if the builders contain the same characters in the same order
    1917     */
    1918    public boolean equals(final TextStringBuilder other) {
    1919        if (this == other) {
    1920            return true;
    1921        }
    1922        if (other == null) {
    1923            return false;
    1924        }
    1925        if (this.size != other.size) {
    1926            return false;
    1927        }
    1928        // Be aware not to use Arrays.equals(buffer, other.buffer) for equals() method
    1929        // as length of the buffers may be different (TEXT-211)
    1930        final char[] thisBuf = this.buffer;
    1931        final char[] otherBuf = other.buffer;
    1932        for (int i = size - 1; i >= 0; i--) {
    1933            if (thisBuf[i] != otherBuf[i]) {
    1934                return false;
    1935            }
    1936        }
    1937        return true;
    1938    }
    1939
    1940    /**
    1941     * Tests the contents of this builder against another to see if they contain the same character content ignoring
    1942     * case.
    1943     *
    1944     * @param other the object to check, null returns false
    1945     * @return true if the builders contain the same characters in the same order
    1946     */
    1947    public boolean equalsIgnoreCase(final TextStringBuilder other) {
    1948        if (this == other) {
    1949            return true;
    1950        }
    1951        if (this.size != other.size) {
    1952            return false;
    1953        }
    1954        final char[] thisBuf = this.buffer;
    1955        final char[] otherBuf = other.buffer;
    1956        for (int i = size - 1; i >= 0; i--) {
    1957            final char c1 = thisBuf[i];
    1958            final char c2 = otherBuf[i];
    1959            if (c1 != c2 && Character.toUpperCase(c1) != Character.toUpperCase(c2)) {
    1960                return false;
    1961            }
    1962        }
    1963        return true;
    1964    }
    1965
    1966    /**
    1967     * Converts this instance to a String.
    1968     *
    1969     * @return This instance as a String
    1970     * @see #toString()
    1971     * @since 1.12.0
    1972     */
    1973    @Override
    1974    public String get() {
    1975        return toString();
    1976    }
    1977
    1978    /**
    1979     * Gets a direct reference to internal storage, not for public consumption.
    1980     */
    1981    char[] getBuffer() {
    1982        return buffer;
    1983    }
    1984
    1985    /**
    1986     * Copies this character array into the specified array.
    1987     *
    1988     * @param target the target array, null will cause an array to be created
    1989     * @return The input array, unless that was null or too small
    1990     */
    1991    public char[] getChars(char[] target) {
    1992        final int len = length();
    1993        if (target == null || target.length < len) {
    1994            target = new char[len];
    1995        }
    1996        System.arraycopy(buffer, 0, target, 0, len);
    1997        return target;
    1998    }
    1999
    2000    /**
    2001     * Copies this character array into the specified array.
    2002     *
    2003     * @param startIndex first index to copy, inclusive, must be valid.
    2004     * @param endIndex last index to copy, exclusive, must be valid.
    2005     * @param target the target array, must not be null or too small.
    2006     * @param targetIndex the index to start copying in target.
    2007     * @throws NullPointerException if the array is null.
    2008     * @throws IndexOutOfBoundsException if any index is invalid.
    2009     */
    2010    public void getChars(final int startIndex, final int endIndex, final char[] target, final int targetIndex) {
    2011        if (startIndex < 0) {
    2012            throw new StringIndexOutOfBoundsException(startIndex);
    2013        }
    2014        if (endIndex < 0 || endIndex > length()) {
    2015            throw new StringIndexOutOfBoundsException(endIndex);
    2016        }
    2017        if (startIndex > endIndex) {
    2018            throw new StringIndexOutOfBoundsException("end < start");
    2019        }
    2020        System.arraycopy(buffer, startIndex, target, targetIndex, endIndex - startIndex);
    2021    }
    2022
    2023    /**
    2024     * Gets the text to be appended when a new line is added.
    2025     *
    2026     * @return The new line text, null means use system default
    2027     */
    2028    public String getNewLineText() {
    2029        return newLine;
    2030    }
    2031
    2032    /**
    2033     * Gets the text to be appended when null is added.
    2034     *
    2035     * @return The null text, null means no append
    2036     */
    2037    public String getNullText() {
    2038        return nullText;
    2039    }
    2040
    2041    /**
    2042     * Gets a suitable hash code for this builder.
    2043     *
    2044     * @return a hash code
    2045     */
    2046    @Override
    2047    public int hashCode() {
    2048        // no allocation
    2049        final char[] buf = buffer;
    2050        int result = 0;
    2051        for (int i = 0; i < size; i++) {
    2052            result = 31 * result + buf[i];
    2053        }
    2054        return result;
    2055    }
    2056
    2057    /**
    2058     * Searches the string builder to find the first reference to the specified char.
    2059     *
    2060     * @param ch the character to find
    2061     * @return The first index of the character, or -1 if not found
    2062     */
    2063    public int indexOf(final char ch) {
    2064        return indexOf(ch, 0);
    2065    }
    2066
    2067    /**
    2068     * Searches the string builder to find the first reference to the specified char.
    2069     *
    2070     * @param ch the character to find
    2071     * @param startIndex the index to start at, invalid index rounded to edge
    2072     * @return The first index of the character, or -1 if not found
    2073     */
    2074    public int indexOf(final char ch, int startIndex) {
    2075        startIndex = Math.max(0, startIndex);
    2076        if (startIndex >= size) {
    2077            return StringUtils.INDEX_NOT_FOUND;
    2078        }
    2079        final char[] thisBuf = buffer;
    2080        for (int i = startIndex; i < size; i++) {
    2081            if (thisBuf[i] == ch) {
    2082                return i;
    2083            }
    2084        }
    2085        return StringUtils.INDEX_NOT_FOUND;
    2086    }
    2087
    2088    /**
    2089     * Searches the string builder to find the first reference to the specified string.
    2090     * <p>
    2091     * Note that a null input string will return -1, whereas the JDK throws an exception.
    2092     * </p>
    2093     *
    2094     * @param str the string to find, null returns -1
    2095     * @return The first index of the string, or -1 if not found
    2096     */
    2097    public int indexOf(final String str) {
    2098        return indexOf(str, 0);
    2099    }
    2100
    2101    /**
    2102     * Searches the string builder to find the first reference to the specified string starting searching from the given
    2103     * index.
    2104     * <p>
    2105     * Note that a null input string will return -1, whereas the JDK throws an exception.
    2106     * </p>
    2107     *
    2108     * @param str the string to find, null returns -1
    2109     * @param startIndex the index to start at, invalid index rounded to edge
    2110     * @return The first index of the string, or -1 if not found
    2111     */
    2112    public int indexOf(final String str, int startIndex) {
    2113        startIndex = Math.max(0, startIndex);
    2114        if (str == null || startIndex >= size) {
    2115            return StringUtils.INDEX_NOT_FOUND;
    2116        }
    2117        final int strLen = str.length();
    2118        if (strLen == 1) {
    2119            return indexOf(str.charAt(0), startIndex);
    2120        }
    2121        if (strLen == 0) {
    2122            return startIndex;
    2123        }
    2124        if (strLen > size) {
    2125            return StringUtils.INDEX_NOT_FOUND;
    2126        }
    2127        final char[] thisBuf = buffer;
    2128        final int len = size - strLen + 1;
    2129        outer: for (int i = startIndex; i < len; i++) {
    2130            for (int j = 0; j < strLen; j++) {
    2131                if (str.charAt(j) != thisBuf[i + j]) {
    2132                    continue outer;
    2133                }
    2134            }
    2135            return i;
    2136        }
    2137        return StringUtils.INDEX_NOT_FOUND;
    2138    }
    2139
    2140    /**
    2141     * Searches the string builder using the matcher to find the first match.
    2142     * <p>
    2143     * Matchers can be used to perform advanced searching behavior. For example you could write a matcher to find the
    2144     * character 'a' followed by a number.
    2145     * </p>
    2146     *
    2147     * @param matcher the matcher to use, null returns -1
    2148     * @return The first index matched, or -1 if not found
    2149     */
    2150    public int indexOf(final StringMatcher matcher) {
    2151        return indexOf(matcher, 0);
    2152    }
    2153
    2154    /**
    2155     * Searches the string builder using the matcher to find the first match searching from the given index.
    2156     * <p>
    2157     * Matchers can be used to perform advanced searching behavior. For example you could write a matcher to find the
    2158     * character 'a' followed by a number.
    2159     * </p>
    2160     *
    2161     * @param matcher the matcher to use, null returns -1
    2162     * @param startIndex the index to start at, invalid index rounded to edge
    2163     * @return The first index matched, or -1 if not found
    2164     */
    2165    public int indexOf(final StringMatcher matcher, int startIndex) {
    2166        startIndex = Math.max(0, startIndex);
    2167        if (matcher == null || startIndex >= size) {
    2168            return StringUtils.INDEX_NOT_FOUND;
    2169        }
    2170        final int len = size;
    2171        final char[] buf = buffer;
    2172        for (int i = startIndex; i < len; i++) {
    2173            if (matcher.isMatch(buf, i, startIndex, len) > 0) {
    2174                return i;
    2175            }
    2176        }
    2177        return StringUtils.INDEX_NOT_FOUND;
    2178    }
    2179
    2180    /**
    2181     * Inserts the value into this builder.
    2182     *
    2183     * @param index the index to add at, must be valid
    2184     * @param value the value to insert
    2185     * @return this, to enable chaining
    2186     * @throws IndexOutOfBoundsException if the index is invalid
    2187     */
    2188    public TextStringBuilder insert(final int index, final boolean value) {
    2189        validateIndex(index);
    2190        if (value) {
    2191            ensureCapacityInternal(size + TRUE_STRING_SIZE);
    2192            System.arraycopy(buffer, index, buffer, index + TRUE_STRING_SIZE, size - index);
    2193            appendTrue(index);
    2194        } else {
    2195            ensureCapacityInternal(size + FALSE_STRING_SIZE);
    2196            System.arraycopy(buffer, index, buffer, index + FALSE_STRING_SIZE, size - index);
    2197            appendFalse(index);
    2198        }
    2199        return this;
    2200    }
    2201
    2202    /**
    2203     * Inserts the value into this builder.
    2204     *
    2205     * @param index the index to add at, must be valid
    2206     * @param value the value to insert
    2207     * @return this, to enable chaining
    2208     * @throws IndexOutOfBoundsException if the index is invalid
    2209     */
    2210    public TextStringBuilder insert(final int index, final char value) {
    2211        validateIndex(index);
    2212        ensureCapacityInternal(size + 1);
    2213        System.arraycopy(buffer, index, buffer, index + 1, size - index);
    2214        buffer[index] = value;
    2215        size++;
    2216        return this;
    2217    }
    2218
    2219    /**
    2220     * Inserts the character array into this builder. Inserting null will use the stored null text value.
    2221     *
    2222     * @param index the index to add at, must be valid
    2223     * @param chars the char array to insert
    2224     * @return this, to enable chaining
    2225     * @throws IndexOutOfBoundsException if the index is invalid
    2226     */
    2227    public TextStringBuilder insert(final int index, final char[] chars) {
    2228        validateIndex(index);
    2229        if (chars == null) {
    2230            return insert(index, nullText);
    2231        }
    2232        final int len = chars.length;
    2233        if (len > 0) {
    2234            ensureCapacityInternal(size + len);
    2235            System.arraycopy(buffer, index, buffer, index + len, size - index);
    2236            System.arraycopy(chars, 0, buffer, index, len);
    2237            size += len;
    2238        }
    2239        return this;
    2240    }
    2241
    2242    /**
    2243     * Inserts part of the character array into this builder. Inserting null will use the stored null text value.
    2244     *
    2245     * @param index the index to add at, must be valid
    2246     * @param chars the char array to insert
    2247     * @param offset the offset into the character array to start at, must be valid
    2248     * @param length the length of the character array part to copy, must be positive
    2249     * @return this, to enable chaining
    2250     * @throws IndexOutOfBoundsException if any index is invalid
    2251     */
    2252    public TextStringBuilder insert(final int index, final char[] chars, final int offset, final int length) {
    2253        validateIndex(index);
    2254        if (chars == null) {
    2255            return insert(index, nullText);
    2256        }
    2257        if (offset < 0 || offset > chars.length) {
    2258            throw new StringIndexOutOfBoundsException("Invalid offset: " + offset);
    2259        }
    2260        if (length < 0 || offset + length > chars.length) {
    2261            throw new StringIndexOutOfBoundsException("Invalid length: " + length);
    2262        }
    2263        if (length > 0) {
    2264            ensureCapacityInternal(size + length);
    2265            System.arraycopy(buffer, index, buffer, index + length, size - index);
    2266            System.arraycopy(chars, offset, buffer, index, length);
    2267            size += length;
    2268        }
    2269        return this;
    2270    }
    2271
    2272    /**
    2273     * Inserts the value into this builder.
    2274     *
    2275     * @param index the index to add at, must be valid
    2276     * @param value the value to insert
    2277     * @return this, to enable chaining
    2278     * @throws IndexOutOfBoundsException if the index is invalid
    2279     */
    2280    public TextStringBuilder insert(final int index, final double value) {
    2281        return insert(index, String.valueOf(value));
    2282    }
    2283
    2284    /**
    2285     * Inserts the value into this builder.
    2286     *
    2287     * @param index the index to add at, must be valid
    2288     * @param value the value to insert
    2289     * @return this, to enable chaining
    2290     * @throws IndexOutOfBoundsException if the index is invalid
    2291     */
    2292    public TextStringBuilder insert(final int index, final float value) {
    2293        return insert(index, String.valueOf(value));
    2294    }
    2295
    2296    /**
    2297     * Inserts the value into this builder.
    2298     *
    2299     * @param index the index to add at, must be valid
    2300     * @param value the value to insert
    2301     * @return this, to enable chaining
    2302     * @throws IndexOutOfBoundsException if the index is invalid
    2303     */
    2304    public TextStringBuilder insert(final int index, final int value) {
    2305        return insert(index, String.valueOf(value));
    2306    }
    2307
    2308    /**
    2309     * Inserts the value into this builder.
    2310     *
    2311     * @param index the index to add at, must be valid
    2312     * @param value the value to insert
    2313     * @return this, to enable chaining
    2314     * @throws IndexOutOfBoundsException if the index is invalid
    2315     */
    2316    public TextStringBuilder insert(final int index, final long value) {
    2317        return insert(index, String.valueOf(value));
    2318    }
    2319
    2320    /**
    2321     * Inserts the string representation of an object into this builder. Inserting null will use the stored null text
    2322     * value.
    2323     *
    2324     * @param index the index to add at, must be valid
    2325     * @param obj the object to insert
    2326     * @return this, to enable chaining
    2327     * @throws IndexOutOfBoundsException if the index is invalid
    2328     */
    2329    public TextStringBuilder insert(final int index, final Object obj) {
    2330        if (obj == null) {
    2331            return insert(index, nullText);
    2332        }
    2333        return insert(index, obj.toString());
    2334    }
    2335
    2336    /**
    2337     * Inserts the string into this builder. Inserting null will use the stored null text value.
    2338     *
    2339     * @param index the index to add at, must be valid
    2340     * @param str the string to insert
    2341     * @return this, to enable chaining
    2342     * @throws IndexOutOfBoundsException if the index is invalid
    2343     */
    2344    public TextStringBuilder insert(final int index, String str) {
    2345        validateIndex(index);
    2346        if (str == null) {
    2347            str = nullText;
    2348        }
    2349        if (str != null) {
    2350            final int strLen = str.length();
    2351            if (strLen > 0) {
    2352                final int newSize = size + strLen;
    2353                ensureCapacityInternal(newSize);
    2354                System.arraycopy(buffer, index, buffer, index + strLen, size - index);
    2355                size = newSize;
    2356                str.getChars(0, strLen, buffer, index);
    2357            }
    2358        }
    2359        return this;
    2360    }
    2361
    2362    /**
    2363     * Checks is the string builder is empty (convenience Collections API style method).
    2364     * <p>
    2365     * This method is the same as checking {@link #length()} and is provided to match the API of Collections.
    2366     * </p>
    2367     *
    2368     * @return {@code true} if the size is {@code 0}.
    2369     */
    2370    public boolean isEmpty() {
    2371        return size == 0;
    2372    }
    2373
    2374    /**
    2375     * Checks is the string builder is not empty.
    2376     * <p>
    2377     * This method is the same as checking {@link #length()}.
    2378     * </p>
    2379     *
    2380     * @return {@code true} if the size is not {@code 0}.
    2381     * @since 1.9
    2382     */
    2383    public boolean isNotEmpty() {
    2384        return size != 0;
    2385    }
    2386
    2387    /**
    2388     * Gets whether the internal buffer has been reallocated.
    2389     *
    2390     * @return Whether the internal buffer has been reallocated.
    2391     * @since 1.9
    2392     */
    2393    public boolean isReallocated() {
    2394        return reallocations > 0;
    2395    }
    2396
    2397    /**
    2398     * Searches the string builder to find the last reference to the specified char.
    2399     *
    2400     * @param ch the character to find
    2401     * @return The last index of the character, or -1 if not found
    2402     */
    2403    public int lastIndexOf(final char ch) {
    2404        return lastIndexOf(ch, size - 1);
    2405    }
    2406
    2407    /**
    2408     * Searches the string builder to find the last reference to the specified char.
    2409     *
    2410     * @param ch the character to find
    2411     * @param startIndex the index to start at, invalid index rounded to edge
    2412     * @return The last index of the character, or -1 if not found
    2413     */
    2414    public int lastIndexOf(final char ch, int startIndex) {
    2415        startIndex = startIndex >= size ? size - 1 : startIndex;
    2416        if (startIndex < 0) {
    2417            return StringUtils.INDEX_NOT_FOUND;
    2418        }
    2419        for (int i = startIndex; i >= 0; i--) {
    2420            if (buffer[i] == ch) {
    2421                return i;
    2422            }
    2423        }
    2424        return StringUtils.INDEX_NOT_FOUND;
    2425    }
    2426
    2427    /**
    2428     * Searches the string builder to find the last reference to the specified string.
    2429     * <p>
    2430     * Note that a null input string will return -1, whereas the JDK throws an exception.
    2431     * </p>
    2432     *
    2433     * @param str the string to find, null returns -1
    2434     * @return The last index of the string, or -1 if not found
    2435     */
    2436    public int lastIndexOf(final String str) {
    2437        return lastIndexOf(str, size - 1);
    2438    }
    2439
    2440    /**
    2441     * Searches the string builder to find the last reference to the specified string starting searching from the given
    2442     * index.
    2443     * <p>
    2444     * Note that a null input string will return -1, whereas the JDK throws an exception.
    2445     * </p>
    2446     *
    2447     * @param str the string to find, null returns -1
    2448     * @param startIndex the index to start at, invalid index rounded to edge
    2449     * @return The last index of the string, or -1 if not found
    2450     */
    2451    public int lastIndexOf(final String str, int startIndex) {
    2452        startIndex = startIndex >= size ? size - 1 : startIndex;
    2453        if (str == null || startIndex < 0) {
    2454            return StringUtils.INDEX_NOT_FOUND;
    2455        }
    2456        final int strLen = str.length();
    2457        if (strLen > 0 && strLen <= size) {
    2458            if (strLen == 1) {
    2459                return lastIndexOf(str.charAt(0), startIndex);
    2460            }
    2461
    2462            outer: for (int i = startIndex - strLen + 1; i >= 0; i--) {
    2463                for (int j = 0; j < strLen; j++) {
    2464                    if (str.charAt(j) != buffer[i + j]) {
    2465                        continue outer;
    2466                    }
    2467                }
    2468                return i;
    2469            }
    2470
    2471        } else if (strLen == 0) {
    2472            return startIndex;
    2473        }
    2474        return StringUtils.INDEX_NOT_FOUND;
    2475    }
    2476
    2477    /**
    2478     * Searches the string builder using the matcher to find the last match.
    2479     * <p>
    2480     * Matchers can be used to perform advanced searching behavior. For example you could write a matcher to find the
    2481     * character 'a' followed by a number.
    2482     * </p>
    2483     *
    2484     * @param matcher the matcher to use, null returns -1
    2485     * @return The last index matched, or -1 if not found
    2486     */
    2487    public int lastIndexOf(final StringMatcher matcher) {
    2488        return lastIndexOf(matcher, size);
    2489    }
    2490
    2491    /**
    2492     * Searches the string builder using the matcher to find the last match searching from the given index.
    2493     * <p>
    2494     * Matchers can be used to perform advanced searching behavior. For example you could write a matcher to find the
    2495     * character 'a' followed by a number.
    2496     * </p>
    2497     *
    2498     * @param matcher the matcher to use, null returns -1
    2499     * @param startIndex the index to start at, invalid index rounded to edge
    2500     * @return The last index matched, or -1 if not found
    2501     */
    2502    public int lastIndexOf(final StringMatcher matcher, int startIndex) {
    2503        startIndex = startIndex >= size ? size - 1 : startIndex;
    2504        if (matcher == null || startIndex < 0) {
    2505            return StringUtils.INDEX_NOT_FOUND;
    2506        }
    2507        final char[] buf = buffer;
    2508        final int endIndex = startIndex + 1;
    2509        for (int i = startIndex; i >= 0; i--) {
    2510            if (matcher.isMatch(buf, i, 0, endIndex) > 0) {
    2511                return i;
    2512            }
    2513        }
    2514        return StringUtils.INDEX_NOT_FOUND;
    2515    }
    2516
    2517    /**
    2518     * Extracts the leftmost characters from the string builder without throwing an exception.
    2519     * <p>
    2520     * This method extracts the left {@code length} characters from the builder. If this many characters are not
    2521     * available, the whole builder is returned. Thus the returned string may be shorter than the length requested.
    2522     * </p>
    2523     *
    2524     * @param length the number of characters to extract, negative returns empty string
    2525     * @return The new string
    2526     */
    2527    public String leftString(final int length) {
    2528        if (length <= 0) {
    2529            return StringUtils.EMPTY;
    2530        }
    2531        if (length >= size) {
    2532            return new String(buffer, 0, size);
    2533        }
    2534        return new String(buffer, 0, length);
    2535    }
    2536
    2537    /**
    2538     * Gets the length of the string builder.
    2539     *
    2540     * @return The length
    2541     */
    2542    @Override
    2543    public int length() {
    2544        return size;
    2545    }
    2546
    2547    /**
    2548     * Extracts some characters from the middle of the string builder without throwing an exception.
    2549     * <p>
    2550     * This method extracts {@code length} characters from the builder at the specified index. If the index is negative
    2551     * it is treated as zero. If the index is greater than the builder size, it is treated as the builder size. If the
    2552     * length is negative, the empty string is returned. If insufficient characters are available in the builder, as
    2553     * much as possible is returned. Thus the returned string may be shorter than the length requested.
    2554     * </p>
    2555     *
    2556     * @param index the index to start at, negative means zero
    2557     * @param length the number of characters to extract, negative returns empty string
    2558     * @return The new string
    2559     */
    2560    public String midString(int index, final int length) {
    2561        if (index < 0) {
    2562            index = 0;
    2563        }
    2564        if (length <= 0 || index >= size) {
    2565            return StringUtils.EMPTY;
    2566        }
    2567        if (size <= index + length) {
    2568            return new String(buffer, index, size - index);
    2569        }
    2570        return new String(buffer, index, length);
    2571    }
    2572
    2573    /**
    2574     * Minimizes the capacity to the actual length of the string.
    2575     *
    2576     * @return this, to enable chaining
    2577     */
    2578    public TextStringBuilder minimizeCapacity() {
    2579        if (buffer.length > size) {
    2580            reallocate(size);
    2581        }
    2582        return this;
    2583    }
    2584
    2585    /**
    2586     * If possible, reads chars from the provided {@link CharBuffer} directly into underlying character buffer without
    2587     * making extra copies.
    2588     *
    2589     * @param charBuffer CharBuffer to read.
    2590     * @return The number of characters read.
    2591     *
    2592     * @see #appendTo(Appendable)
    2593     * @since 1.9
    2594     */
    2595    public int readFrom(final CharBuffer charBuffer) {
    2596        final int oldSize = size;
    2597        final int remaining = charBuffer.remaining();
    2598        ensureCapacityInternal(size + remaining);
    2599        charBuffer.get(buffer, size, remaining);
    2600        size += remaining;
    2601        return size - oldSize;
    2602    }
    2603
    2604    /**
    2605     * If possible, reads all chars from the provided {@link Readable} directly into underlying character buffer without
    2606     * making extra copies.
    2607     *
    2608     * @param readable object to read from
    2609     * @return The number of characters read
    2610     * @throws IOException if an I/O error occurs.
    2611     *
    2612     * @see #appendTo(Appendable)
    2613     */
    2614    public int readFrom(final Readable readable) throws IOException {
    2615        if (readable instanceof Reader) {
    2616            return readFrom((Reader) readable);
    2617        }
    2618        if (readable instanceof CharBuffer) {
    2619            return readFrom((CharBuffer) readable);
    2620        }
    2621        final int oldSize = size;
    2622        while (true) {
    2623            ensureCapacityInternal(size + 1);
    2624            final CharBuffer buf = CharBuffer.wrap(buffer, size, buffer.length - size);
    2625            final int read = readable.read(buf);
    2626            if (read == EOS) {
    2627                break;
    2628            }
    2629            size += read;
    2630        }
    2631        return size - oldSize;
    2632    }
    2633
    2634    /**
    2635     * If possible, reads all chars from the provided {@link Reader} directly into underlying character buffer without
    2636     * making extra copies.
    2637     *
    2638     * @param reader Reader to read.
    2639     * @return The number of characters read or -1 if we reached the end of stream.
    2640     * @throws IOException if an I/O error occurs.
    2641     *
    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 a new line is added.
    3018     *
    3019     * @param newLine the new line text, null means use system default
    3020     * @return this, to enable chaining
    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}