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