Source code
Description: source: package: org.apache.commons.lang3.text, class: StrTokenizer

    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 *      https://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.ArrayList;
    020import java.util.Arrays;
    021import java.util.Collections;
    022import java.util.List;
    023import java.util.ListIterator;
    024import java.util.NoSuchElementException;
    025import java.util.StringTokenizer;
    026
    027import org.apache.commons.lang3.ArrayUtils;
    028import org.apache.commons.lang3.StringUtils;
    029
    030/**
    031 * Tokenizes a string based on delimiters (separators)
    032 * and supporting quoting and ignored character concepts.
    033 * <p>
    034 * This class can split a String into many smaller strings. It aims
    035 * to do a similar job to {@link java.util.StringTokenizer StringTokenizer},
    036 * however it offers much more control and flexibility including implementing
    037 * the {@link ListIterator} interface. By default, it is set up
    038 * like {@link StringTokenizer}.
    039 * </p>
    040 * <p>
    041 * The input String is split into a number of <em>tokens</em>.
    042 * Each token is separated from the next String by a <em>delimiter</em>.
    043 * One or more delimiter characters must be specified.
    044 * </p>
    045 * <p>
    046 * Each token may be surrounded by quotes.
    047 * The <em>quote</em> matcher specifies the quote character(s).
    048 * A quote may be escaped within a quoted section by duplicating itself.
    049 * </p>
    050 * <p>
    051 * Between each token and the delimiter are potentially characters that need trimming.
    052 * The <em>trimmer</em> matcher specifies these characters.
    053 * One usage might be to trim whitespace characters.
    054 * </p>
    055 * <p>
    056 * At any point outside the quotes there might potentially be invalid characters.
    057 * The <em>ignored</em> matcher specifies these characters to be removed.
    058 * One usage might be to remove new line characters.
    059 * </p>
    060 * <p>
    061 * Empty tokens may be removed or returned as null.
    062 * </p>
    063 * <pre>
    064 * "a,b,c"         - Three tokens "a","b","c"   (comma delimiter)
    065 * " a, b , c "    - Three tokens "a","b","c"   (default CSV processing trims whitespace)
    066 * "a, ", b ,", c" - Three tokens "a, " , " b ", ", c" (quoted text untouched)
    067 * </pre>
    068 *
    069 * <table>
    070 *  <caption>StrTokenizer properties and options</caption>
    071 *  <tr>
    072 *   <th>Property</th><th>Type</th><th>Default</th>
    073 *  </tr>
    074 *  <tr>
    075 *   <td>delim</td><td>CharSetMatcher</td><td>{ \t\n\r\f}</td>
    076 *  </tr>
    077 *  <tr>
    078 *   <td>quote</td><td>NoneMatcher</td><td>{}</td>
    079 *  </tr>
    080 *  <tr>
    081 *   <td>ignore</td><td>NoneMatcher</td><td>{}</td>
    082 *  </tr>
    083 *  <tr>
    084 *   <td>emptyTokenAsNull</td><td>boolean</td><td>false</td>
    085 *  </tr>
    086 *  <tr>
    087 *   <td>ignoreEmptyTokens</td><td>boolean</td><td>true</td>
    088 *  </tr>
    089 * </table>
    090 *
    091 * @since 2.2
    092 * @deprecated As of <a href="https://commons.apache.org/proper/commons-lang/changes-report.html#a3.6">3.6</a>, use Apache Commons Text
    093 * <a href="https://commons.apache.org/proper/commons-text/javadocs/api-release/org/apache/commons/text/StringTokenizer.html">
    094 * StringTokenizer</a>.
    095 */
    096@Deprecated
    097public class StrTokenizer implements ListIterator<String>, Cloneable {
    098
    099    // @formatter:off
    100    private static final StrTokenizer CSV_TOKENIZER_PROTOTYPE = new StrTokenizer()
    101            .setDelimiterMatcher(StrMatcher.commaMatcher())
    102            .setQuoteMatcher(StrMatcher.doubleQuoteMatcher())
    103            .setIgnoredMatcher(StrMatcher.noneMatcher())
    104            .setTrimmerMatcher(StrMatcher.trimMatcher())
    105            .setEmptyTokenAsNull(false)
    106            .setIgnoreEmptyTokens(false);
    107    // @formatter:on
    108
    109    // @formatter:off
    110    private static final StrTokenizer TSV_TOKENIZER_PROTOTYPE = new StrTokenizer()
    111            .setDelimiterMatcher(StrMatcher.tabMatcher())
    112            .setQuoteMatcher(StrMatcher.doubleQuoteMatcher())
    113            .setIgnoredMatcher(StrMatcher.noneMatcher())
    114            .setTrimmerMatcher(StrMatcher.trimMatcher())
    115            .setEmptyTokenAsNull(false)
    116            .setIgnoreEmptyTokens(false);
    117    // @formatter:on
    118
    119    /**
    120     * Gets a clone of {@code CSV_TOKENIZER_PROTOTYPE}.
    121     *
    122     * @return a clone of {@code CSV_TOKENIZER_PROTOTYPE}.
    123     */
    124    private static StrTokenizer getCSVClone() {
    125        return (StrTokenizer) CSV_TOKENIZER_PROTOTYPE.clone();
    126    }
    127    /**
    128     * Gets a new tokenizer instance which parses Comma Separated Value strings
    129     * initializing it with the given input.  The default for CSV processing
    130     * will be trim whitespace from both ends (which can be overridden with
    131     * the setTrimmer method).
    132     * <p>
    133     * You must call a "reset" method to set the string which you want to parse.
    134     * </p>
    135     * @return a new tokenizer instance which parses Comma Separated Value strings.
    136     */
    137    public static StrTokenizer getCSVInstance() {
    138        return getCSVClone();
    139    }
    140    /**
    141     * Gets a new tokenizer instance which parses Comma Separated Value strings
    142     * initializing it with the given input.  The default for CSV processing
    143     * will be trim whitespace from both ends (which can be overridden with
    144     * the setTrimmer method).
    145     *
    146     * @param input  the text to parse.
    147     * @return a new tokenizer instance which parses Comma Separated Value strings.
    148     */
    149    public static StrTokenizer getCSVInstance(final char[] input) {
    150        final StrTokenizer tok = getCSVClone();
    151        tok.reset(input);
    152        return tok;
    153    }
    154
    155    /**
    156     * Gets a new tokenizer instance which parses Comma Separated Value strings
    157     * initializing it with the given input.  The default for CSV processing
    158     * will be trim whitespace from both ends (which can be overridden with
    159     * the setTrimmer method).
    160     *
    161     * @param input  the text to parse.
    162     * @return a new tokenizer instance which parses Comma Separated Value strings.
    163     */
    164    public static StrTokenizer getCSVInstance(final String input) {
    165        final StrTokenizer tok = getCSVClone();
    166        tok.reset(input);
    167        return tok;
    168    }
    169    /**
    170     * Gets a clone of {@code TSV_TOKENIZER_PROTOTYPE}.
    171     *
    172     * @return a clone of {@code TSV_TOKENIZER_PROTOTYPE}.
    173     */
    174    private static StrTokenizer getTSVClone() {
    175        return (StrTokenizer) TSV_TOKENIZER_PROTOTYPE.clone();
    176    }
    177
    178    /**
    179     * Gets a new tokenizer instance which parses Tab Separated Value strings.
    180     * The default for CSV processing will be trim whitespace from both ends
    181     * (which can be overridden with the setTrimmer method).
    182     * <p>
    183     * You must call a "reset" method to set the string which you want to parse.
    184     * </p>
    185     * @return a new tokenizer instance which parses Tab Separated Value strings.
    186     */
    187    public static StrTokenizer getTSVInstance() {
    188        return getTSVClone();
    189    }
    190
    191    /**
    192     * Gets a new tokenizer instance which parses Tab Separated Value strings.
    193     * The default for CSV processing will be trim whitespace from both ends
    194     * (which can be overridden with the setTrimmer method).
    195     *
    196     * @param input  the string to parse.
    197     * @return a new tokenizer instance which parses Tab Separated Value strings.
    198     */
    199    public static StrTokenizer getTSVInstance(final char[] input) {
    200        final StrTokenizer tok = getTSVClone();
    201        tok.reset(input);
    202        return tok;
    203    }
    204
    205    /**
    206     * Gets a new tokenizer instance which parses Tab Separated Value strings.
    207     * The default for CSV processing will be trim whitespace from both ends
    208     * (which can be overridden with the setTrimmer method).
    209     *
    210     * @param input  the string to parse.
    211     * @return a new tokenizer instance which parses Tab Separated Value strings.
    212     */
    213    public static StrTokenizer getTSVInstance(final String input) {
    214        final StrTokenizer tok = getTSVClone();
    215        tok.reset(input);
    216        return tok;
    217    }
    218    /** The text to work on. */
    219    private char[] chars;
    220
    221    /** The parsed tokens */
    222    private String[] tokens;
    223
    224    /** The current iteration position */
    225    private int tokenPos;
    226
    227    /** The delimiter matcher */
    228    private StrMatcher delimMatcher = StrMatcher.splitMatcher();
    229
    230    /** The quote matcher */
    231    private StrMatcher quoteMatcher = StrMatcher.noneMatcher();
    232
    233    /** The ignored matcher */
    234    private StrMatcher ignoredMatcher = StrMatcher.noneMatcher();
    235
    236    /** The trimmer matcher */
    237    private StrMatcher trimmerMatcher = StrMatcher.noneMatcher();
    238
    239    /** Whether to return empty tokens as null */
    240    private boolean emptyAsNull;
    241
    242    /** Whether to ignore empty tokens */
    243    private boolean ignoreEmptyTokens = true;
    244
    245    /**
    246     * Constructs a tokenizer splitting on space, tab, newline and formfeed
    247     * as per StringTokenizer, but with no text to tokenize.
    248     * <p>
    249     * This constructor is normally used with {@link #reset(String)}.
    250     * </p>
    251     */
    252    public StrTokenizer() {
    253        this.chars = null;
    254    }
    255
    256    /**
    257     * Constructs a tokenizer splitting on space, tab, newline and formfeed
    258     * as per StringTokenizer.
    259     *
    260     * @param input  the string which is to be parsed, not cloned.
    261     */
    262    public StrTokenizer(final char[] input) {
    263        this.chars = ArrayUtils.clone(input);
    264    }
    265
    266    /**
    267     * Constructs a tokenizer splitting on the specified character.
    268     *
    269     * @param input  the string which is to be parsed, not cloned.
    270     * @param delim the field delimiter character.
    271     */
    272    public StrTokenizer(final char[] input, final char delim) {
    273        this(input);
    274        setDelimiterChar(delim);
    275    }
    276
    277    /**
    278     * Constructs a tokenizer splitting on the specified delimiter character
    279     * and handling quotes using the specified quote character.
    280     *
    281     * @param input  the string which is to be parsed, not cloned.
    282     * @param delim  the field delimiter character.
    283     * @param quote  the field quoted string character.
    284     */
    285    public StrTokenizer(final char[] input, final char delim, final char quote) {
    286        this(input, delim);
    287        setQuoteChar(quote);
    288    }
    289
    290    /**
    291     * Constructs a tokenizer splitting on the specified string.
    292     *
    293     * @param input  the string which is to be parsed, not cloned.
    294     * @param delim the field delimiter string.
    295     */
    296    public StrTokenizer(final char[] input, final String delim) {
    297        this(input);
    298        setDelimiterString(delim);
    299    }
    300
    301    /**
    302     * Constructs a tokenizer splitting using the specified delimiter matcher.
    303     *
    304     * @param input  the string which is to be parsed, not cloned.
    305     * @param delim  the field delimiter matcher.
    306     */
    307    public StrTokenizer(final char[] input, final StrMatcher delim) {
    308        this(input);
    309        setDelimiterMatcher(delim);
    310    }
    311
    312    /**
    313     * Constructs a tokenizer splitting using the specified delimiter matcher
    314     * and handling quotes using the specified quote matcher.
    315     *
    316     * @param input  the string which is to be parsed, not cloned.
    317     * @param delim  the field delimiter character.
    318     * @param quote  the field quoted string character.
    319     */
    320    public StrTokenizer(final char[] input, final StrMatcher delim, final StrMatcher quote) {
    321        this(input, delim);
    322        setQuoteMatcher(quote);
    323    }
    324
    325    /**
    326     * Constructs a tokenizer splitting on space, tab, newline and formfeed
    327     * as per StringTokenizer.
    328     *
    329     * @param input  the string which is to be parsed.
    330     */
    331    public StrTokenizer(final String input) {
    332        if (input != null) {
    333            chars = input.toCharArray();
    334        } else {
    335            chars = null;
    336        }
    337    }
    338
    339    /**
    340     * Constructs a tokenizer splitting on the specified delimiter character.
    341     *
    342     * @param input  the string which is to be parsed.
    343     * @param delim  the field delimiter character.
    344     */
    345    public StrTokenizer(final String input, final char delim) {
    346        this(input);
    347        setDelimiterChar(delim);
    348    }
    349
    350    /**
    351     * Constructs a tokenizer splitting on the specified delimiter character
    352     * and handling quotes using the specified quote character.
    353     *
    354     * @param input  the string which is to be parsed.
    355     * @param delim  the field delimiter character.
    356     * @param quote  the field quoted string character.
    357     */
    358    public StrTokenizer(final String input, final char delim, final char quote) {
    359        this(input, delim);
    360        setQuoteChar(quote);
    361    }
    362
    363    /**
    364     * Constructs a tokenizer splitting on the specified delimiter string.
    365     *
    366     * @param input  the string which is to be parsed.
    367     * @param delim  the field delimiter string.
    368     */
    369    public StrTokenizer(final String input, final String delim) {
    370        this(input);
    371        setDelimiterString(delim);
    372    }
    373
    374    /**
    375     * Constructs a tokenizer splitting using the specified delimiter matcher.
    376     *
    377     * @param input  the string which is to be parsed.
    378     * @param delim  the field delimiter matcher.
    379     */
    380    public StrTokenizer(final String input, final StrMatcher delim) {
    381        this(input);
    382        setDelimiterMatcher(delim);
    383    }
    384
    385    /**
    386     * Constructs a tokenizer splitting using the specified delimiter matcher
    387     * and handling quotes using the specified quote matcher.
    388     *
    389     * @param input  the string which is to be parsed.
    390     * @param delim  the field delimiter matcher.
    391     * @param quote  the field quoted string matcher.
    392     */
    393    public StrTokenizer(final String input, final StrMatcher delim, final StrMatcher quote) {
    394        this(input, delim);
    395        setQuoteMatcher(quote);
    396    }
    397
    398    /**
    399     * Unsupported ListIterator operation.
    400     *
    401     * @param obj this parameter ignored.
    402     * @throws UnsupportedOperationException always.
    403     */
    404    @Override
    405    public void add(final String obj) {
    406        throw new UnsupportedOperationException("add() is unsupported");
    407    }
    408
    409    /**
    410     * Adds a token to a list, paying attention to the parameters we've set.
    411     *
    412     * @param list  the list to add to.
    413     * @param tok  the token to add.
    414     */
    415    private void addToken(final List<String> list, String tok) {
    416        if (StringUtils.isEmpty(tok)) {
    417            if (isIgnoreEmptyTokens()) {
    418                return;
    419            }
    420            if (isEmptyTokenAsNull()) {
    421                tok = null;
    422            }
    423        }
    424        list.add(tok);
    425    }
    426
    427    /**
    428     * Checks if tokenization has been done, and if not then do it.
    429     */
    430    private void checkTokenized() {
    431        if (tokens == null) {
    432            if (chars == null) {
    433                // still call tokenize as subclass may do some work
    434                final List<String> split = tokenize(null, 0, 0);
    435                tokens = split.toArray(ArrayUtils.EMPTY_STRING_ARRAY);
    436            } else {
    437                final List<String> split = tokenize(chars, 0, chars.length);
    438                tokens = split.toArray(ArrayUtils.EMPTY_STRING_ARRAY);
    439            }
    440        }
    441    }
    442
    443    /**
    444     * Creates a new instance of this Tokenizer. The new instance is reset so
    445     * that it will be at the start of the token list.
    446     * If a {@link CloneNotSupportedException} is caught, return {@code null}.
    447     *
    448     * @return a new instance of this Tokenizer which has been reset.
    449     */
    450    @Override
    451    public Object clone() {
    452        try {
    453            return cloneReset();
    454        } catch (final CloneNotSupportedException ex) {
    455            return null;
    456        }
    457    }
    458
    459    /**
    460     * Creates a new instance of this Tokenizer. The new instance is reset so that
    461     * it will be at the start of the token list.
    462     *
    463     * @return a new instance of this Tokenizer which has been reset.
    464     * @throws CloneNotSupportedException if there is a problem cloning.
    465     */
    466    Object cloneReset() throws CloneNotSupportedException {
    467        // this method exists to enable 100% test coverage
    468        final StrTokenizer cloned = (StrTokenizer) super.clone();
    469        if (cloned.chars != null) {
    470            cloned.chars = cloned.chars.clone();
    471        }
    472        cloned.reset();
    473        return cloned;
    474    }
    475
    476    /**
    477     * Gets the String content that the tokenizer is parsing.
    478     *
    479     * @return the string content being parsed.
    480     */
    481    public String getContent() {
    482        if (chars == null) {
    483            return null;
    484        }
    485        return new String(chars);
    486    }
    487
    488    /**
    489     * Gets the field delimiter matcher.
    490     *
    491     * @return the delimiter matcher in use.
    492     */
    493    public StrMatcher getDelimiterMatcher() {
    494        return this.delimMatcher;
    495    }
    496
    497    // Ignored
    498    /**
    499     * Gets the ignored character matcher.
    500     * <p>
    501     * These characters are ignored when parsing the String, unless they are
    502     * within a quoted region.
    503     * The default value is not to ignore anything.
    504     * </p>
    505     *
    506     * @return the ignored matcher in use.
    507     */
    508    public StrMatcher getIgnoredMatcher() {
    509        return ignoredMatcher;
    510    }
    511
    512    /**
    513     * Gets the quote matcher currently in use.
    514     * <p>
    515     * The quote character is used to wrap data between the tokens.
    516     * This enables delimiters to be entered as data.
    517     * The default value is '"' (double quote).
    518     * </p>
    519     *
    520     * @return the quote matcher in use.
    521     */
    522    public StrMatcher getQuoteMatcher() {
    523        return quoteMatcher;
    524    }
    525
    526    /**
    527     * Gets a copy of the full token list as an independent modifiable array.
    528     *
    529     * @return the tokens as a String array.
    530     */
    531    public String[] getTokenArray() {
    532        checkTokenized();
    533        return tokens.clone();
    534    }
    535
    536    /**
    537     * Gets a copy of the full token list as an independent modifiable list.
    538     *
    539     * @return the tokens as a String array.
    540     */
    541    public List<String> getTokenList() {
    542        checkTokenized();
    543        final List<String> list = new ArrayList<>(tokens.length);
    544        list.addAll(Arrays.asList(tokens));
    545        return list;
    546    }
    547
    548    /**
    549     * Gets the trimmer character matcher.
    550     * <p>
    551     * These characters are trimmed off on each side of the delimiter
    552     * until the token or quote is found.
    553     * The default value is not to trim anything.
    554     * </p>
    555     *
    556     * @return the trimmer matcher in use.
    557     */
    558    public StrMatcher getTrimmerMatcher() {
    559        return trimmerMatcher;
    560    }
    561
    562    /**
    563     * Checks whether there are any more tokens.
    564     *
    565     * @return true if there are more tokens.
    566     */
    567    @Override
    568    public boolean hasNext() {
    569        checkTokenized();
    570        return tokenPos < tokens.length;
    571    }
    572
    573    /**
    574     * Checks whether there are any previous tokens that can be iterated to.
    575     *
    576     * @return true if there are previous tokens.
    577     */
    578    @Override
    579    public boolean hasPrevious() {
    580        checkTokenized();
    581        return tokenPos > 0;
    582    }
    583
    584    /**
    585     * Gets whether the tokenizer currently returns empty tokens as null.
    586     * The default for this property is false.
    587     *
    588     * @return true if empty tokens are returned as null.
    589     */
    590    public boolean isEmptyTokenAsNull() {
    591        return this.emptyAsNull;
    592    }
    593
    594    /**
    595     * Gets whether the tokenizer currently ignores empty tokens.
    596     * The default for this property is true.
    597     *
    598     * @return true if empty tokens are not returned.
    599     */
    600    public boolean isIgnoreEmptyTokens() {
    601        return ignoreEmptyTokens;
    602    }
    603
    604    /**
    605     * Checks if the characters at the index specified match the quote
    606     * already matched in readNextToken().
    607     *
    608     * @param srcChars  the character array being tokenized.
    609     * @param pos  the position to check for a quote.
    610     * @param len  the length of the character array being tokenized.
    611     * @param quoteStart  the start position of the matched quote, 0 if no quoting.
    612     * @param quoteLen  the length of the matched quote, 0 if no quoting.
    613     * @return true if a quote is matched.
    614     */
    615    private boolean isQuote(final char[] srcChars, final int pos, final int len, final int quoteStart, final int quoteLen) {
    616        for (int i = 0; i < quoteLen; i++) {
    617            if (pos + i >= len || srcChars[pos + i] != srcChars[quoteStart + i]) {
    618                return false;
    619            }
    620        }
    621        return true;
    622    }
    623
    624    /**
    625     * Gets the next token.
    626     *
    627     * @return the next String token.
    628     * @throws NoSuchElementException if there are no more elements.
    629     */
    630    @Override
    631    public String next() {
    632        if (hasNext()) {
    633            return tokens[tokenPos++];
    634        }
    635        throw new NoSuchElementException();
    636    }
    637
    638    /**
    639     * Gets the index of the next token to return.
    640     *
    641     * @return the next token index.
    642     */
    643    @Override
    644    public int nextIndex() {
    645        return tokenPos;
    646    }
    647
    648    /**
    649     * Gets the next token from the String.
    650     * Equivalent to {@link #next()} except it returns null rather than
    651     * throwing {@link NoSuchElementException} when no tokens remain.
    652     *
    653     * @return the next sequential token, or null when no more tokens are found.
    654     */
    655    public String nextToken() {
    656        if (hasNext()) {
    657            return tokens[tokenPos++];
    658        }
    659        return null;
    660    }
    661
    662    /**
    663     * Gets the token previous to the last returned token.
    664     *
    665     * @return the previous token.
    666     */
    667    @Override
    668    public String previous() {
    669        if (hasPrevious()) {
    670            return tokens[--tokenPos];
    671        }
    672        throw new NoSuchElementException();
    673    }
    674
    675    /**
    676     * Gets the index of the previous token.
    677     *
    678     * @return the previous token index.
    679     */
    680    @Override
    681    public int previousIndex() {
    682        return tokenPos - 1;
    683    }
    684
    685    /**
    686     * Gets the previous token from the String.
    687     *
    688     * @return the previous sequential token, or null when no more tokens are found.
    689     */
    690    public String previousToken() {
    691        if (hasPrevious()) {
    692            return tokens[--tokenPos];
    693        }
    694        return null;
    695    }
    696
    697    /**
    698     * Reads character by character through the String to get the next token.
    699     *
    700     * @param srcChars  the character array being tokenized.
    701     * @param start  the first character of field.
    702     * @param len  the length of the character array being tokenized.
    703     * @param workArea  a temporary work area.
    704     * @param tokenList  the list of parsed tokens.
    705     * @return the starting position of the next field (the character
    706     *  immediately after the delimiter), or -1 if end of string found.
    707     */
    708    private int readNextToken(final char[] srcChars, int start, final int len, final StrBuilder workArea, final List<String> tokenList) {
    709        // skip all leading whitespace, unless it is the
    710        // field delimiter or the quote character
    711        while (start < len) {
    712            final int removeLen = Math.max(
    713                    getIgnoredMatcher().isMatch(srcChars, start, start, len),
    714                    getTrimmerMatcher().isMatch(srcChars, start, start, len));
    715            if (removeLen == 0 ||
    716                getDelimiterMatcher().isMatch(srcChars, start, start, len) > 0 ||
    717                getQuoteMatcher().isMatch(srcChars, start, start, len) > 0) {
    718                break;
    719            }
    720            start += removeLen;
    721        }
    722
    723        // handle reaching end
    724        if (start >= len) {
    725            addToken(tokenList, StringUtils.EMPTY);
    726            return -1;
    727        }
    728
    729        // handle empty token
    730        final int delimLen = getDelimiterMatcher().isMatch(srcChars, start, start, len);
    731        if (delimLen > 0) {
    732            addToken(tokenList, StringUtils.EMPTY);
    733            return start + delimLen;
    734        }
    735
    736        // handle found token
    737        final int quoteLen = getQuoteMatcher().isMatch(srcChars, start, start, len);
    738        if (quoteLen > 0) {
    739            return readWithQuotes(srcChars, start + quoteLen, len, workArea, tokenList, start, quoteLen);
    740        }
    741        return readWithQuotes(srcChars, start, len, workArea, tokenList, 0, 0);
    742    }
    743
    744    /**
    745     * Reads a possibly quoted string token.
    746     *
    747     * @param srcChars  the character array being tokenized.
    748     * @param start  the first character of field.
    749     * @param len  the length of the character array being tokenized.
    750     * @param workArea  a temporary work area.
    751     * @param tokenList  the list of parsed tokens.
    752     * @param quoteStart  the start position of the matched quote, 0 if no quoting.
    753     * @param quoteLen  the length of the matched quote, 0 if no quoting.
    754     * @return the starting position of the next field (the character
    755     *  immediately after the delimiter, or if end of string found,
    756     *  then the length of string.
    757     */
    758    private int readWithQuotes(final char[] srcChars, final int start, final int len, final StrBuilder workArea,
    759                               final List<String> tokenList, final int quoteStart, final int quoteLen) {
    760        // Loop until we've found the end of the quoted
    761        // string or the end of the input
    762        workArea.clear();
    763        int pos = start;
    764        boolean quoting = quoteLen > 0;
    765        int trimStart = 0;
    766
    767        while (pos < len) {
    768            // quoting mode can occur several times throughout a string
    769            // we must switch between quoting and non-quoting until we
    770            // encounter a non-quoted delimiter, or end of string
    771            if (quoting) {
    772                // In quoting mode
    773
    774                // If we've found a quote character, see if it's
    775                // followed by a second quote.  If so, then we need
    776                // to actually put the quote character into the token
    777                // rather than end the token.
    778                if (isQuote(srcChars, pos, len, quoteStart, quoteLen)) {
    779                    if (isQuote(srcChars, pos + quoteLen, len, quoteStart, quoteLen)) {
    780                        // matched pair of quotes, thus an escaped quote
    781                        workArea.append(srcChars, pos, quoteLen);
    782                        pos += quoteLen * 2;
    783                        trimStart = workArea.size();
    784                        continue;
    785                    }
    786
    787                    // end of quoting
    788                    quoting = false;
    789                    pos += quoteLen;
    790                    continue;
    791                }
    792
    793            } else {
    794                // Not in quoting mode
    795
    796                // check for delimiter, and thus end of token
    797                final int delimLen = getDelimiterMatcher().isMatch(srcChars, pos, start, len);
    798                if (delimLen > 0) {
    799                    // return condition when end of token found
    800                    addToken(tokenList, workArea.substring(0, trimStart));
    801                    return pos + delimLen;
    802                }
    803
    804                // check for quote, and thus back into quoting mode
    805                if (quoteLen > 0 && isQuote(srcChars, pos, len, quoteStart, quoteLen)) {
    806                    quoting = true;
    807                    pos += quoteLen;
    808                    continue;
    809                }
    810
    811                // check for ignored (outside quotes), and ignore
    812                final int ignoredLen = getIgnoredMatcher().isMatch(srcChars, pos, start, len);
    813                if (ignoredLen > 0) {
    814                    pos += ignoredLen;
    815                    continue;
    816                }
    817
    818                // check for trimmed character
    819                // don't yet know if it's at the end, so copy to workArea
    820                // use trimStart to keep track of trim at the end
    821                final int trimmedLen = getTrimmerMatcher().isMatch(srcChars, pos, start, len);
    822                if (trimmedLen > 0) {
    823                    workArea.append(srcChars, pos, trimmedLen);
    824                    pos += trimmedLen;
    825                    continue;
    826                }
    827            }
    828            // copy regular character from inside quotes
    829            workArea.append(srcChars[pos++]);
    830            trimStart = workArea.size();
    831        }
    832
    833        // return condition when end of string found
    834        addToken(tokenList, workArea.substring(0, trimStart));
    835        return -1;
    836    }
    837
    838    /**
    839     * Unsupported ListIterator operation.
    840     *
    841     * @throws UnsupportedOperationException always.
    842     */
    843    @Override
    844    public void remove() {
    845        throw new UnsupportedOperationException("remove() is unsupported");
    846    }
    847
    848    /**
    849     * Resets this tokenizer, forgetting all parsing and iteration already completed.
    850     * <p>
    851     * This method allows the same tokenizer to be reused for the same String.
    852     * </p>
    853     *
    854     * @return {@code this} instance.
    855     */
    856    public StrTokenizer reset() {
    857        tokenPos = 0;
    858        tokens = null;
    859        return this;
    860    }
    861
    862    /**
    863     * Reset this tokenizer, giving it a new input string to parse.
    864     * In this manner you can re-use a tokenizer with the same settings
    865     * on multiple input lines.
    866     *
    867     * @param input  the new character array to tokenize, not cloned, null sets no text to parse.
    868     * @return {@code this} instance.
    869     */
    870    public StrTokenizer reset(final char[] input) {
    871        reset();
    872        this.chars = ArrayUtils.clone(input);
    873        return this;
    874    }
    875
    876    /**
    877     * Reset this tokenizer, giving it a new input string to parse.
    878     * In this manner you can re-use a tokenizer with the same settings
    879     * on multiple input lines.
    880     *
    881     * @param input  the new string to tokenize, null sets no text to parse.
    882     * @return {@code this} instance.
    883     */
    884    public StrTokenizer reset(final String input) {
    885        reset();
    886        if (input != null) {
    887            this.chars = input.toCharArray();
    888        } else {
    889            this.chars = null;
    890        }
    891        return this;
    892    }
    893
    894    /**
    895     * Unsupported ListIterator operation.
    896     *
    897     * @param obj this parameter ignored.
    898     * @throws UnsupportedOperationException always.
    899     */
    900    @Override
    901    public void set(final String obj) {
    902        throw new UnsupportedOperationException("set() is unsupported");
    903    }
    904
    905    /**
    906     * Sets the field delimiter character.
    907     *
    908     * @param delim  the delimiter character to use.
    909     * @return this, to enable chaining.
    910     */
    911    public StrTokenizer setDelimiterChar(final char delim) {
    912        return setDelimiterMatcher(StrMatcher.charMatcher(delim));
    913    }
    914
    915    /**
    916     * Sets the field delimiter matcher.
    917     * <p>
    918     * The delimiter is used to separate one token from another.
    919     * </p>
    920     *
    921     * @param delim  the delimiter matcher to use.
    922     * @return this, to enable chaining.
    923     */
    924    public StrTokenizer setDelimiterMatcher(final StrMatcher delim) {
    925        if (delim == null) {
    926            this.delimMatcher = StrMatcher.noneMatcher();
    927        } else {
    928            this.delimMatcher = delim;
    929        }
    930        return this;
    931    }
    932
    933    /**
    934     * Sets the field delimiter string.
    935     *
    936     * @param delim  the delimiter string to use.
    937     * @return this, to enable chaining.
    938     */
    939    public StrTokenizer setDelimiterString(final String delim) {
    940        return setDelimiterMatcher(StrMatcher.stringMatcher(delim));
    941    }
    942
    943    /**
    944     * Sets whether the tokenizer should return empty tokens as null.
    945     * The default for this property is false.
    946     *
    947     * @param emptyAsNull  whether empty tokens are returned as null.
    948     * @return this, to enable chaining.
    949     */
    950    public StrTokenizer setEmptyTokenAsNull(final boolean emptyAsNull) {
    951        this.emptyAsNull = emptyAsNull;
    952        return this;
    953    }
    954
    955    /**
    956     * Sets the character to ignore.
    957     * <p>
    958     * This character is ignored when parsing the String, unless it is
    959     * within a quoted region.
    960     *
    961     * @param ignored  the ignored character to use.
    962     * @return this, to enable chaining.
    963     */
    964    public StrTokenizer setIgnoredChar(final char ignored) {
    965        return setIgnoredMatcher(StrMatcher.charMatcher(ignored));
    966    }
    967
    968    /**
    969     * Sets the matcher for characters to ignore.
    970     * <p>
    971     * These characters are ignored when parsing the String, unless they are
    972     * within a quoted region.
    973     * </p>
    974     *
    975     * @param ignored  the ignored matcher to use, null ignored.
    976     * @return {@code this} instance.
    977     */
    978    public StrTokenizer setIgnoredMatcher(final StrMatcher ignored) {
    979        if (ignored != null) {
    980            this.ignoredMatcher = ignored;
    981        }
    982        return this;
    983    }
    984
    985    /**
    986     * Sets whether the tokenizer should ignore and not return empty tokens.
    987     * The default for this property is true.
    988     *
    989     * @param ignoreEmptyTokens  whether empty tokens are not returned.
    990     * @return {@code this} instance.
    991     */
    992    public StrTokenizer setIgnoreEmptyTokens(final boolean ignoreEmptyTokens) {
    993        this.ignoreEmptyTokens = ignoreEmptyTokens;
    994        return this;
    995    }
    996
    997    /**
    998     * Sets the quote character to use.
    999     * <p>
    1000     * The quote character is used to wrap data between the tokens.
    1001     * This enables delimiters to be entered as data.
    1002     * </p>
    1003     *
    1004     * @param quote  the quote character to use.
    1005     * @return {@code this} instance.
    1006     */
    1007    public StrTokenizer setQuoteChar(final char quote) {
    1008        return setQuoteMatcher(StrMatcher.charMatcher(quote));
    1009    }
    1010
    1011    /**
    1012     * Sets the quote matcher to use.
    1013     * <p>
    1014     * The quote character is used to wrap data between the tokens.
    1015     * This enables delimiters to be entered as data.
    1016     * </p>
    1017     *
    1018     * @param quote  the quote matcher to use, null ignored.
    1019     * @return {@code this} instance.
    1020     */
    1021    public StrTokenizer setQuoteMatcher(final StrMatcher quote) {
    1022        if (quote != null) {
    1023            this.quoteMatcher = quote;
    1024        }
    1025        return this;
    1026    }
    1027
    1028    /**
    1029     * Sets the matcher for characters to trim.
    1030     * <p>
    1031     * These characters are trimmed off on each side of the delimiter
    1032     * until the token or quote is found.
    1033     * </p>
    1034     *
    1035     * @param trimmer  the trimmer matcher to use, null ignored.
    1036     * @return {@code this} instance.
    1037     */
    1038    public StrTokenizer setTrimmerMatcher(final StrMatcher trimmer) {
    1039        if (trimmer != null) {
    1040            this.trimmerMatcher = trimmer;
    1041        }
    1042        return this;
    1043    }
    1044
    1045    // API
    1046    /**
    1047     * Gets the number of tokens found in the String.
    1048     *
    1049     * @return the number of matched tokens.
    1050     */
    1051    public int size() {
    1052        checkTokenized();
    1053        return tokens.length;
    1054    }
    1055
    1056    /**
    1057     * Internal method to performs the tokenization.
    1058     * <p>
    1059     * Most users of this class do not need to call this method. This method
    1060     * will be called automatically by other (public) methods when required.
    1061     * </p>
    1062     * <p>
    1063     * This method exists to allow subclasses to add code before or after the
    1064     * tokenization. For example, a subclass could alter the character array,
    1065     * offset or count to be parsed, or call the tokenizer multiple times on
    1066     * multiple strings. It is also be possible to filter the results.
    1067     * </p>
    1068     * <p>
    1069     * {@link StrTokenizer} will always pass a zero offset and a count
    1070     * equal to the length of the array to this method, however a subclass
    1071     * may pass other values, or even an entirely different array.
    1072     * </p>
    1073     *
    1074     * @param srcChars  the character array being tokenized, may be null.
    1075     * @param offset  the start position within the character array, must be valid.
    1076     * @param count  the number of characters to tokenize, must be valid.
    1077     * @return the modifiable list of String tokens, unmodifiable if null array or zero count.
    1078     */
    1079    protected List<String> tokenize(final char[] srcChars, final int offset, final int count) {
    1080        if (ArrayUtils.isEmpty(srcChars)) {
    1081            return Collections.emptyList();
    1082        }
    1083        final StrBuilder buf = new StrBuilder();
    1084        final List<String> tokenList = new ArrayList<>();
    1085        int pos = offset;
    1086
    1087        // loop around the entire buffer
    1088        while (pos >= 0 && pos < count) {
    1089            // find next token
    1090            pos = readNextToken(srcChars, pos, count, buf, tokenList);
    1091
    1092            // handle case where end of string is a delimiter
    1093            if (pos >= count) {
    1094                addToken(tokenList, StringUtils.EMPTY);
    1095            }
    1096        }
    1097        return tokenList;
    1098    }
    1099
    1100    /**
    1101     * Gets the String content that the tokenizer is parsing.
    1102     *
    1103     * @return the string content being parsed.
    1104     */
    1105    @Override
    1106    public String toString() {
    1107        if (tokens == null) {
    1108            return "StrTokenizer[not tokenized yet]";
    1109        }
    1110        return "StrTokenizer" + getTokenList();
    1111    }
    1112
    1113}