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