    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.lang3.text;
    018
    019import java.util.Arrays;
    020
    021import org.apache.commons.lang3.StringUtils;
    022
    023/**
    024 * A matcher class that can be queried to determine if a character array
    025 * portion matches.
    026 * <p>
    027 * This class comes complete with various factory methods.
    028 * If these do not suffice, you can subclass and implement your own matcher.
    029 *
    030 * @since 2.2
    031 * @deprecated as of 3.6, use commons-text
    032 * <a href="https://commons.apache.org/proper/commons-text/javadocs/api-release/org/apache/commons/text/StringMatcherFactory.html">
    033 * StringMatcherFactory</a> instead
    034 */
    035@Deprecated
    036public abstract class StrMatcher {
    037
    038    /**
    039     * Matches the comma character.
    040     */
    041    private static final StrMatcher COMMA_MATCHER = new CharMatcher(',');
    042    /**
    043     * Matches the tab character.
    044     */
    045    private static final StrMatcher TAB_MATCHER = new CharMatcher('\t');
    046    /**
    047     * Matches the space character.
    048     */
    049    private static final StrMatcher SPACE_MATCHER = new CharMatcher(' ');
    050    /**
    051     * Matches the same characters as StringTokenizer,
    052     * namely space, tab, newline, formfeed.
    053     */
    054    private static final StrMatcher SPLIT_MATCHER = new CharSetMatcher(" \t\n\r\f".toCharArray());
    055    /**
    056     * Matches the String trim() whitespace characters.
    057     */
    058    private static final StrMatcher TRIM_MATCHER = new TrimMatcher();
    059    /**
    060     * Matches the double quote character.
    061     */
    062    private static final StrMatcher SINGLE_QUOTE_MATCHER = new CharMatcher('\'');
    063    /**
    064     * Matches the double quote character.
    065     */
    066    private static final StrMatcher DOUBLE_QUOTE_MATCHER = new CharMatcher('"');
    067    /**
    068     * Matches the single or double quote character.
    069     */
    070    private static final StrMatcher QUOTE_MATCHER = new CharSetMatcher("'\"".toCharArray());
    071    /**
    072     * Matches no characters.
    073     */
    074    private static final StrMatcher NONE_MATCHER = new NoMatcher();
    075
    076    // -----------------------------------------------------------------------
    077
    078    /**
    079     * Returns a matcher which matches the comma character.
    080     *
    081     * @return a matcher for a comma
    082     */
    083    public static StrMatcher commaMatcher() {
    084        return COMMA_MATCHER;
    085    }
    086
    087    /**
    088     * Returns a matcher which matches the tab character.
    089     *
    090     * @return a matcher for a tab
    091     */
    092    public static StrMatcher tabMatcher() {
    093        return TAB_MATCHER;
    094    }
    095
    096    /**
    097     * Returns a matcher which matches the space character.
    098     *
    099     * @return a matcher for a space
    100     */
    101    public static StrMatcher spaceMatcher() {
    102        return SPACE_MATCHER;
    103    }
    104
    105    /**
    106     * Matches the same characters as StringTokenizer,
    107     * namely space, tab, newline and formfeed.
    108     *
    109     * @return the split matcher
    110     */
    111    public static StrMatcher splitMatcher() {
    112        return SPLIT_MATCHER;
    113    }
    114
    115    /**
    116     * Matches the String trim() whitespace characters.
    117     *
    118     * @return the trim matcher
    119     */
    120    public static StrMatcher trimMatcher() {
    121        return TRIM_MATCHER;
    122    }
    123
    124    /**
    125     * Returns a matcher which matches the single quote character.
    126     *
    127     * @return a matcher for a single quote
    128     */
    129    public static StrMatcher singleQuoteMatcher() {
    130        return SINGLE_QUOTE_MATCHER;
    131    }
    132
    133    /**
    134     * Returns a matcher which matches the double quote character.
    135     *
    136     * @return a matcher for a double quote
    137     */
    138    public static StrMatcher doubleQuoteMatcher() {
    139        return DOUBLE_QUOTE_MATCHER;
    140    }
    141
    142    /**
    143     * Returns a matcher which matches the single or double quote character.
    144     *
    145     * @return a matcher for a single or double quote
    146     */
    147    public static StrMatcher quoteMatcher() {
    148        return QUOTE_MATCHER;
    149    }
    150
    151    /**
    152     * Matches no characters.
    153     *
    154     * @return a matcher that matches nothing
    155     */
    156    public static StrMatcher noneMatcher() {
    157        return NONE_MATCHER;
    158    }
    159
    160    /**
    161     * Constructor that creates a matcher from a character.
    162     *
    163     * @param ch  the character to match, must not be null
    164     * @return a new Matcher for the given char
    165     */
    166    public static StrMatcher charMatcher(final char ch) {
    167        return new CharMatcher(ch);
    168    }
    169
    170    /**
    171     * Constructor that creates a matcher from a set of characters.
    172     *
    173     * @param chars  the characters to match, null or empty matches nothing
    174     * @return a new matcher for the given char[]
    175     */
    176    public static StrMatcher charSetMatcher(final char... chars) {
    177        if (chars == null || chars.length == 0) {
    178            return NONE_MATCHER;
    179        }
    180        if (chars.length == 1) {
    181            return new CharMatcher(chars[0]);
    182        }
    183        return new CharSetMatcher(chars);
    184    }
    185
    186    /**
    187     * Constructor that creates a matcher from a string representing a set of characters.
    188     *
    189     * @param chars  the characters to match, null or empty matches nothing
    190     * @return a new Matcher for the given characters
    191     */
    192    public static StrMatcher charSetMatcher(final String chars) {
    193        if (StringUtils.isEmpty(chars)) {
    194            return NONE_MATCHER;
    195        }
    196        if (chars.length() == 1) {
    197            return new CharMatcher(chars.charAt(0));
    198        }
    199        return new CharSetMatcher(chars.toCharArray());
    200    }
    201
    202    /**
    203     * Constructor that creates a matcher from a string.
    204     *
    205     * @param str  the string to match, null or empty matches nothing
    206     * @return a new Matcher for the given String
    207     */
    208    public static StrMatcher stringMatcher(final String str) {
    209        if (StringUtils.isEmpty(str)) {
    210            return NONE_MATCHER;
    211        }
    212        return new StringMatcher(str);
    213    }
    214
    215    //-----------------------------------------------------------------------
    216    /**
    217     * Constructor.
    218     */
    219    protected StrMatcher() {
    220        super();
    221    }
    222
    223    /**
    224     * Returns the number of matching characters, zero for no match.
    225     * <p>
    226     * This method is called to check for a match.
    227     * The parameter <code>pos</code> represents the current position to be
    228     * checked in the string <code>buffer</code> (a character array which must
    229     * not be changed).
    230     * The API guarantees that <code>pos</code> is a valid index for <code>buffer</code>.
    231     * <p>
    232     * The character array may be larger than the active area to be matched.
    233     * Only values in the buffer between the specified indices may be accessed.
    234     * <p>
    235     * The matching code may check one character or many.
    236     * It may check characters preceding <code>pos</code> as well as those
    237     * after, so long as no checks exceed the bounds specified.
    238     * <p>
    239     * It must return zero for no match, or a positive number if a match was found.
    240     * The number indicates the number of characters that matched.
    241     *
    242     * @param buffer  the text content to match against, do not change
    243     * @param pos  the starting position for the match, valid for buffer
    244     * @param bufferStart  the first active index in the buffer, valid for buffer
    245     * @param bufferEnd  the end index (exclusive) of the active buffer, valid for buffer
    246     * @return the number of matching characters, zero for no match
    247     */
    248    public abstract int isMatch(char[] buffer, int pos, int bufferStart, int bufferEnd);
    249
    250    /**
    251     * Returns the number of matching characters, zero for no match.
    252     * <p>
    253     * This method is called to check for a match.
    254     * The parameter <code>pos</code> represents the current position to be
    255     * checked in the string <code>buffer</code> (a character array which must
    256     * not be changed).
    257     * The API guarantees that <code>pos</code> is a valid index for <code>buffer</code>.
    258     * <p>
    259     * The matching code may check one character or many.
    260     * It may check characters preceding <code>pos</code> as well as those after.
    261     * <p>
    262     * It must return zero for no match, or a positive number if a match was found.
    263     * The number indicates the number of characters that matched.
    264     *
    265     * @param buffer  the text content to match against, do not change
    266     * @param pos  the starting position for the match, valid for buffer
    267     * @return the number of matching characters, zero for no match
    268     * @since 2.4
    269     */
    270    public int isMatch(final char[] buffer, final int pos) {
    271        return isMatch(buffer, pos, 0, buffer.length);
    272    }
    273
    274    //-----------------------------------------------------------------------
    275    /**
    276     * Class used to define a set of characters for matching purposes.
    277     */
    278    static final class CharSetMatcher extends StrMatcher {
    279        /** The set of characters to match. */
    280        private final char[] chars;
    281
    282        /**
    283         * Constructor that creates a matcher from a character array.
    284         *
    285         * @param chars  the characters to match, must not be null
    286         */
    287        CharSetMatcher(final char chars[]) {
    288            super();
    289            this.chars = chars.clone();
    290            Arrays.sort(this.chars);
    291        }
    292
    293        /**
    294         * Returns whether or not the given character matches.
    295         *
    296         * @param buffer  the text content to match against, do not change
    297         * @param pos  the starting position for the match, valid for buffer
    298         * @param bufferStart  the first active index in the buffer, valid for buffer
    299         * @param bufferEnd  the end index of the active buffer, valid for buffer
    300         * @return the number of matching characters, zero for no match
    301         */
    302        @Override
    303        public int isMatch(final char[] buffer, final int pos, final int bufferStart, final int bufferEnd) {
    304            return Arrays.binarySearch(chars, buffer[pos]) >= 0 ? 1 : 0;
    305        }
    306    }
    307
    308    //-----------------------------------------------------------------------
    309    /**
    310     * Class used to define a character for matching purposes.
    311     */
    312    static final class CharMatcher extends StrMatcher {
    313        /** The character to match. */
    314        private final char ch;
    315
    316        /**
    317         * Constructor that creates a matcher that matches a single character.
    318         *
    319         * @param ch  the character to match
    320         */
    321        CharMatcher(final char ch) {
    322            super();
    323            this.ch = ch;
    324        }
    325
    326        /**
    327         * Returns whether or not the given character matches.
    328         *
    329         * @param buffer  the text content to match against, do not change
    330         * @param pos  the starting position for the match, valid for buffer
    331         * @param bufferStart  the first active index in the buffer, valid for buffer
    332         * @param bufferEnd  the end index of the active buffer, valid for buffer
    333         * @return the number of matching characters, zero for no match
    334         */
    335        @Override
    336        public int isMatch(final char[] buffer, final int pos, final int bufferStart, final int bufferEnd) {
    337            return ch == buffer[pos] ? 1 : 0;
    338        }
    339    }
    340
    341    //-----------------------------------------------------------------------
    342    /**
    343     * Class used to define a set of characters for matching purposes.
    344     */
    345    static final class StringMatcher extends StrMatcher {
    346        /** The string to match, as a character array. */
    347        private final char[] chars;
    348
    349        /**
    350         * Constructor that creates a matcher from a String.
    351         *
    352         * @param str  the string to match, must not be null
    353         */
    354        StringMatcher(final String str) {
    355            super();
    356            chars = str.toCharArray();
    357        }
    358
    359        /**
    360         * Returns whether or not the given text matches the stored string.
    361         *
    362         * @param buffer  the text content to match against, do not change
    363         * @param pos  the starting position for the match, valid for buffer
    364         * @param bufferStart  the first active index in the buffer, valid for buffer
    365         * @param bufferEnd  the end index of the active buffer, valid for buffer
    366         * @return the number of matching characters, zero for no match
    367         */
    368        @Override
    369        public int isMatch(final char[] buffer, int pos, final int bufferStart, final int bufferEnd) {
    370            final int len = chars.length;
    371            if (pos + len > bufferEnd) {
    372                return 0;
    373            }
    374            for (int i = 0; i < chars.length; i++, pos++) {
    375                if (chars[i] != buffer[pos]) {
    376                    return 0;
    377                }
    378            }
    379            return len;
    380        }
    381
    382        @Override
    383        public String toString() {
    384            return super.toString() + ' ' + Arrays.toString(chars);
    385        }
    386
    387    }
    388
    389    //-----------------------------------------------------------------------
    390    /**
    391     * Class used to match no characters.
    392     */
    393    static final class NoMatcher extends StrMatcher {
    394
    395        /**
    396         * Constructs a new instance of <code>NoMatcher</code>.
    397         */
    398        NoMatcher() {
    399            super();
    400        }
    401
    402        /**
    403         * Always returns <code>false</code>.
    404         *
    405         * @param buffer  the text content to match against, do not change
    406         * @param pos  the starting position for the match, valid for buffer
    407         * @param bufferStart  the first active index in the buffer, valid for buffer
    408         * @param bufferEnd  the end index of the active buffer, valid for buffer
    409         * @return the number of matching characters, zero for no match
    410         */
    411        @Override
    412        public int isMatch(final char[] buffer, final int pos, final int bufferStart, final int bufferEnd) {
    413            return 0;
    414        }
    415    }
    416
    417    //-----------------------------------------------------------------------
    418    /**
    419     * Class used to match whitespace as per trim().
    420     */
    421    static final class TrimMatcher extends StrMatcher {
    422
    423        /**
    424         * Constructs a new instance of <code>TrimMatcher</code>.
    425         */
    426        TrimMatcher() {
    427            super();
    428        }
    429
    430        /**
    431         * Returns whether or not the given character matches.
    432         *
    433         * @param buffer  the text content to match against, do not change
    434         * @param pos  the starting position for the match, valid for buffer
    435         * @param bufferStart  the first active index in the buffer, valid for buffer
    436         * @param bufferEnd  the end index of the active buffer, valid for buffer
    437         * @return the number of matching characters, zero for no match
    438         */
    439        @Override
    440        public int isMatch(final char[] buffer, final int pos, final int bufferStart, final int bufferEnd) {
    441            return buffer[pos] <= 32 ? 1 : 0;
    442        }
    443    }
    444
    445}