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;
018
019import java.io.IOException;
020import java.io.Writer;
021
022import org.apache.commons.lang3.text.translate.AggregateTranslator;
023import org.apache.commons.lang3.text.translate.CharSequenceTranslator;
024import org.apache.commons.lang3.text.translate.EntityArrays;
025import org.apache.commons.lang3.text.translate.JavaUnicodeEscaper;
026import org.apache.commons.lang3.text.translate.LookupTranslator;
027import org.apache.commons.lang3.text.translate.NumericEntityEscaper;
028import org.apache.commons.lang3.text.translate.NumericEntityUnescaper;
029import org.apache.commons.lang3.text.translate.OctalUnescaper;
030import org.apache.commons.lang3.text.translate.UnicodeUnescaper;
031import org.apache.commons.lang3.text.translate.UnicodeUnpairedSurrogateRemover;
032
033/**
034 * Escapes and unescapes {@link String}s for
035 * Java, Java Script, HTML and XML.
036 *
037 * <p>#ThreadSafe#</p>
038 * @since 2.0
039 * @deprecated As of 3.6, use Apache Commons Text
040 * <a href="https://commons.apache.org/proper/commons-text/javadocs/api-release/org/apache/commons/text/StringEscapeUtils.html">
041 * StringEscapeUtils</a> instead
042 */
043@Deprecated
044public class StringEscapeUtils {
045
046    /* ESCAPE TRANSLATORS */
047
048    /**
049     * Translator object for escaping Java.
050     *
051     * While {@link #escapeJava(String)} is the expected method of use, this
052     * object allows the Java escaping functionality to be used
053     * as the foundation for a custom translator.
054     *
055     * @since 3.0
056     */
057    public static final CharSequenceTranslator ESCAPE_JAVA =
058          new LookupTranslator(
059            new String[][] {
060              {"\"", "\\\""},
061              {"\\", "\\\\"},
062          }).with(
063            new LookupTranslator(EntityArrays.JAVA_CTRL_CHARS_ESCAPE())
064          ).with(
065            JavaUnicodeEscaper.outsideOf(32, 0x7f)
066        );
067
068    /**
069     * Translator object for escaping EcmaScript/JavaScript.
070     *
071     * While {@link #escapeEcmaScript(String)} is the expected method of use, this
072     * object allows the EcmaScript escaping functionality to be used
073     * as the foundation for a custom translator.
074     *
075     * @since 3.0
076     */
077    public static final CharSequenceTranslator ESCAPE_ECMASCRIPT =
078        new AggregateTranslator(
079            new LookupTranslator(
080                      new String[][] {
081                            {"'", "\\'"},
082                            {"\"", "\\\""},
083                            {"\\", "\\\\"},
084                            {"/", "\\/"}
085                      }),
086            new LookupTranslator(EntityArrays.JAVA_CTRL_CHARS_ESCAPE()),
087            JavaUnicodeEscaper.outsideOf(32, 0x7f)
088        );
089
090    /**
091     * Translator object for escaping Json.
092     *
093     * While {@link #escapeJson(String)} is the expected method of use, this
094     * object allows the Json escaping functionality to be used
095     * as the foundation for a custom translator.
096     *
097     * @since 3.2
098     */
099    public static final CharSequenceTranslator ESCAPE_JSON =
100        new AggregateTranslator(
101            new LookupTranslator(
102                      new String[][] {
103                            {"\"", "\\\""},
104                            {"\\", "\\\\"},
105                            {"/", "\\/"}
106                      }),
107            new LookupTranslator(EntityArrays.JAVA_CTRL_CHARS_ESCAPE()),
108            JavaUnicodeEscaper.outsideOf(32, 0x7f)
109        );
110
111    /**
112     * Translator object for escaping XML.
113     *
114     * While {@link #escapeXml(String)} is the expected method of use, this
115     * object allows the XML escaping functionality to be used
116     * as the foundation for a custom translator.
117     *
118     * @since 3.0
119     * @deprecated use {@link #ESCAPE_XML10} or {@link #ESCAPE_XML11} instead.
120     */
121    @Deprecated
122    public static final CharSequenceTranslator ESCAPE_XML =
123        new AggregateTranslator(
124            new LookupTranslator(EntityArrays.BASIC_ESCAPE()),
125            new LookupTranslator(EntityArrays.APOS_ESCAPE())
126        );
127
128    /**
129     * Translator object for escaping XML 1.0.
130     *
131     * While {@link #escapeXml10(String)} is the expected method of use, this
132     * object allows the XML escaping functionality to be used
133     * as the foundation for a custom translator.
134     *
135     * @since 3.3
136     */
137    public static final CharSequenceTranslator ESCAPE_XML10 =
138        new AggregateTranslator(
139            new LookupTranslator(EntityArrays.BASIC_ESCAPE()),
140            new LookupTranslator(EntityArrays.APOS_ESCAPE()),
141            new LookupTranslator(
142                    new String[][] {
143                            { "\u0000", StringUtils.EMPTY },
144                            { "\u0001", StringUtils.EMPTY },
145                            { "\u0002", StringUtils.EMPTY },
146                            { "\u0003", StringUtils.EMPTY },
147                            { "\u0004", StringUtils.EMPTY },
148                            { "\u0005", StringUtils.EMPTY },
149                            { "\u0006", StringUtils.EMPTY },
150                            { "\u0007", StringUtils.EMPTY },
151                            { "\u0008", StringUtils.EMPTY },
152                            { "\u000b", StringUtils.EMPTY },
153                            { "\u000c", StringUtils.EMPTY },
154                            { "\u000e", StringUtils.EMPTY },
155                            { "\u000f", StringUtils.EMPTY },
156                            { "\u0010", StringUtils.EMPTY },
157                            { "\u0011", StringUtils.EMPTY },
158                            { "\u0012", StringUtils.EMPTY },
159                            { "\u0013", StringUtils.EMPTY },
160                            { "\u0014", StringUtils.EMPTY },
161                            { "\u0015", StringUtils.EMPTY },
162                            { "\u0016", StringUtils.EMPTY },
163                            { "\u0017", StringUtils.EMPTY },
164                            { "\u0018", StringUtils.EMPTY },
165                            { "\u0019", StringUtils.EMPTY },
166                            { "\u001a", StringUtils.EMPTY },
167                            { "\u001b", StringUtils.EMPTY },
168                            { "\u001c", StringUtils.EMPTY },
169                            { "\u001d", StringUtils.EMPTY },
170                            { "\u001e", StringUtils.EMPTY },
171                            { "\u001f", StringUtils.EMPTY },
172                            { "\ufffe", StringUtils.EMPTY },
173                            { "\uffff", StringUtils.EMPTY }
174                    }),
175            NumericEntityEscaper.between(0x7f, 0x84),
176            NumericEntityEscaper.between(0x86, 0x9f),
177            new UnicodeUnpairedSurrogateRemover()
178        );
179
180    /**
181     * Translator object for escaping XML 1.1.
182     *
183     * While {@link #escapeXml11(String)} is the expected method of use, this
184     * object allows the XML escaping functionality to be used
185     * as the foundation for a custom translator.
186     *
187     * @since 3.3
188     */
189    public static final CharSequenceTranslator ESCAPE_XML11 =
190        new AggregateTranslator(
191            new LookupTranslator(EntityArrays.BASIC_ESCAPE()),
192            new LookupTranslator(EntityArrays.APOS_ESCAPE()),
193            new LookupTranslator(
194                    new String[][] {
195                            { "\u0000", StringUtils.EMPTY },
196                            { "\u000b", "&#11;" },
197                            { "\u000c", "&#12;" },
198                            { "\ufffe", StringUtils.EMPTY },
199                            { "\uffff", StringUtils.EMPTY }
200                    }),
201            NumericEntityEscaper.between(0x1, 0x8),
202            NumericEntityEscaper.between(0xe, 0x1f),
203            NumericEntityEscaper.between(0x7f, 0x84),
204            NumericEntityEscaper.between(0x86, 0x9f),
205            new UnicodeUnpairedSurrogateRemover()
206        );
207
208    /**
209     * Translator object for escaping HTML version 3.0.
210     *
211     * While {@link #escapeHtml3(String)} is the expected method of use, this
212     * object allows the HTML escaping functionality to be used
213     * as the foundation for a custom translator.
214     *
215     * @since 3.0
216     */
217    public static final CharSequenceTranslator ESCAPE_HTML3 =
218        new AggregateTranslator(
219            new LookupTranslator(EntityArrays.BASIC_ESCAPE()),
220            new LookupTranslator(EntityArrays.ISO8859_1_ESCAPE())
221        );
222
223    /**
224     * Translator object for escaping HTML version 4.0.
225     *
226     * While {@link #escapeHtml4(String)} is the expected method of use, this
227     * object allows the HTML escaping functionality to be used
228     * as the foundation for a custom translator.
229     *
230     * @since 3.0
231     */
232    public static final CharSequenceTranslator ESCAPE_HTML4 =
233        new AggregateTranslator(
234            new LookupTranslator(EntityArrays.BASIC_ESCAPE()),
235            new LookupTranslator(EntityArrays.ISO8859_1_ESCAPE()),
236            new LookupTranslator(EntityArrays.HTML40_EXTENDED_ESCAPE())
237        );
238
239    /**
240     * Translator object for escaping individual Comma Separated Values.
241     *
242     * While {@link #escapeCsv(String)} is the expected method of use, this
243     * object allows the CSV escaping functionality to be used
244     * as the foundation for a custom translator.
245     *
246     * @since 3.0
247     */
248    public static final CharSequenceTranslator ESCAPE_CSV = new CsvEscaper();
249
250    // TODO: Create a parent class - 'SinglePassTranslator' ?
251    //       It would handle the index checking + length returning,
252    //       and could also have an optimization check method.
253    static class CsvEscaper extends CharSequenceTranslator {
254
255        private static final char CSV_DELIMITER = ',';
256        private static final char CSV_QUOTE = '"';
257        private static final String CSV_QUOTE_STR = String.valueOf(CSV_QUOTE);
258        private static final char[] CSV_SEARCH_CHARS = { CSV_DELIMITER, CSV_QUOTE, CharUtils.CR, CharUtils.LF };
259
260        @Override
261        public int translate(final CharSequence input, final int index, final Writer out) throws IOException {
262
263            if (index != 0) {
264                throw new IllegalStateException("CsvEscaper should never reach the [1] index");
265            }
266
267            if (StringUtils.containsNone(input.toString(), CSV_SEARCH_CHARS)) {
268                out.write(input.toString());
269            } else {
270                out.write(CSV_QUOTE);
271                out.write(StringUtils.replace(input.toString(), CSV_QUOTE_STR, CSV_QUOTE_STR + CSV_QUOTE_STR));
272                out.write(CSV_QUOTE);
273            }
274            return Character.codePointCount(input, 0, input.length());
275        }
276    }
277
278    /* UNESCAPE TRANSLATORS */
279
280    /**
281     * Translator object for unescaping escaped Java.
282     *
283     * While {@link #unescapeJava(String)} is the expected method of use, this
284     * object allows the Java unescaping functionality to be used
285     * as the foundation for a custom translator.
286     *
287     * @since 3.0
288     */
289    // TODO: throw "illegal character: \92" as an Exception if a \ on the end of the Java (as per the compiler)?
290    public static final CharSequenceTranslator UNESCAPE_JAVA =
291        new AggregateTranslator(
292            new OctalUnescaper(),     // .between('\1', '\377'),
293            new UnicodeUnescaper(),
294            new LookupTranslator(EntityArrays.JAVA_CTRL_CHARS_UNESCAPE()),
295            new LookupTranslator(
296                      new String[][] {
297                            {"\\\\", "\\"},
298                            {"\\\"", "\""},
299                            {"\\'", "'"},
300                            {"\\", ""}
301                      })
302        );
303
304    /**
305     * Translator object for unescaping escaped EcmaScript.
306     *
307     * While {@link #unescapeEcmaScript(String)} is the expected method of use, this
308     * object allows the EcmaScript unescaping functionality to be used
309     * as the foundation for a custom translator.
310     *
311     * @since 3.0
312     */
313    public static final CharSequenceTranslator UNESCAPE_ECMASCRIPT = UNESCAPE_JAVA;
314
315    /**
316     * Translator object for unescaping escaped Json.
317     *
318     * While {@link #unescapeJson(String)} is the expected method of use, this
319     * object allows the Json unescaping functionality to be used
320     * as the foundation for a custom translator.
321     *
322     * @since 3.2
323     */
324    public static final CharSequenceTranslator UNESCAPE_JSON = UNESCAPE_JAVA;
325
326    /**
327     * Translator object for unescaping escaped HTML 3.0.
328     *
329     * While {@link #unescapeHtml3(String)} is the expected method of use, this
330     * object allows the HTML unescaping functionality to be used
331     * as the foundation for a custom translator.
332     *
333     * @since 3.0
334     */
335    public static final CharSequenceTranslator UNESCAPE_HTML3 =
336        new AggregateTranslator(
337            new LookupTranslator(EntityArrays.BASIC_UNESCAPE()),
338            new LookupTranslator(EntityArrays.ISO8859_1_UNESCAPE()),
339            new NumericEntityUnescaper()
340        );
341
342    /**
343     * Translator object for unescaping escaped HTML 4.0.
344     *
345     * While {@link #unescapeHtml4(String)} is the expected method of use, this
346     * object allows the HTML unescaping functionality to be used
347     * as the foundation for a custom translator.
348     *
349     * @since 3.0
350     */
351    public static final CharSequenceTranslator UNESCAPE_HTML4 =
352        new AggregateTranslator(
353            new LookupTranslator(EntityArrays.BASIC_UNESCAPE()),
354            new LookupTranslator(EntityArrays.ISO8859_1_UNESCAPE()),
355            new LookupTranslator(EntityArrays.HTML40_EXTENDED_UNESCAPE()),
356            new NumericEntityUnescaper()
357        );
358
359    /**
360     * Translator object for unescaping escaped XML.
361     *
362     * While {@link #unescapeXml(String)} is the expected method of use, this
363     * object allows the XML unescaping functionality to be used
364     * as the foundation for a custom translator.
365     *
366     * @since 3.0
367     */
368    public static final CharSequenceTranslator UNESCAPE_XML =
369        new AggregateTranslator(
370            new LookupTranslator(EntityArrays.BASIC_UNESCAPE()),
371            new LookupTranslator(EntityArrays.APOS_UNESCAPE()),
372            new NumericEntityUnescaper()
373        );
374
375    /**
376     * Translator object for unescaping escaped Comma Separated Value entries.
377     *
378     * While {@link #unescapeCsv(String)} is the expected method of use, this
379     * object allows the CSV unescaping functionality to be used
380     * as the foundation for a custom translator.
381     *
382     * @since 3.0
383     */
384    public static final CharSequenceTranslator UNESCAPE_CSV = new CsvUnescaper();
385
386    static class CsvUnescaper extends CharSequenceTranslator {
387
388        private static final char CSV_DELIMITER = ',';
389        private static final char CSV_QUOTE = '"';
390        private static final String CSV_QUOTE_STR = String.valueOf(CSV_QUOTE);
391        private static final char[] CSV_SEARCH_CHARS = {CSV_DELIMITER, CSV_QUOTE, CharUtils.CR, CharUtils.LF};
392
393        @Override
394        public int translate(final CharSequence input, final int index, final Writer out) throws IOException {
395
396            if (index != 0) {
397                throw new IllegalStateException("CsvUnescaper should never reach the [1] index");
398            }
399
400            if ( input.charAt(0) != CSV_QUOTE || input.charAt(input.length() - 1) != CSV_QUOTE ) {
401                out.write(input.toString());
402                return Character.codePointCount(input, 0, input.length());
403            }
404
405            // strip quotes
406            final String quoteless = input.subSequence(1, input.length() - 1).toString();
407
408            if ( StringUtils.containsAny(quoteless, CSV_SEARCH_CHARS) ) {
409                // deal with escaped quotes; ie) ""
410                out.write(StringUtils.replace(quoteless, CSV_QUOTE_STR + CSV_QUOTE_STR, CSV_QUOTE_STR));
411            } else {
412                out.write(input.toString());
413            }
414            return Character.codePointCount(input, 0, input.length());
415        }
416    }
417
418    /* Helper functions */
419
420    /**
421     * {@link StringEscapeUtils} instances should NOT be constructed in
422     * standard programming.
423     *
424     * <p>Instead, the class should be used as:</p>
425     * <pre>StringEscapeUtils.escapeJava("foo");</pre>
426     *
427     * <p>This constructor is public to permit tools that require a JavaBean
428     * instance to operate.</p>
429     */
430    public StringEscapeUtils() {
431    }
432
433    /**
434     * Escapes the characters in a {@link String} using Java String rules.
435     *
436     * <p>Deals correctly with quotes and control-chars (tab, backslash, cr, ff, etc.) </p>
437     *
438     * <p>So a tab becomes the characters {@code '\\'} and
439     * {@code 't'}.</p>
440     *
441     * <p>The only difference between Java strings and JavaScript strings
442     * is that in JavaScript, a single quote and forward-slash (/) are escaped.</p>
443     *
444     * <p>Example:</p>
445     * <pre>
446     * input string: He didn't say, "Stop!"
447     * output string: He didn't say, \"Stop!\"
448     * </pre>
449     *
450     * @param input  String to escape values in, may be null
451     * @return String with escaped values, {@code null} if null string input
452     */
453    public static final String escapeJava(final String input) {
454        return ESCAPE_JAVA.translate(input);
455    }
456
457    /**
458     * Escapes the characters in a {@link String} using EcmaScript String rules.
459     * <p>Escapes any values it finds into their EcmaScript String form.
460     * Deals correctly with quotes and control-chars (tab, backslash, cr, ff, etc.) </p>
461     *
462     * <p>So a tab becomes the characters {@code '\\'} and
463     * {@code 't'}.</p>
464     *
465     * <p>The only difference between Java strings and EcmaScript strings
466     * is that in EcmaScript, a single quote and forward-slash (/) are escaped.</p>
467     *
468     * <p>Note that EcmaScript is best known by the JavaScript and ActionScript dialects.</p>
469     *
470     * <p>Example:</p>
471     * <pre>
472     * input string: He didn't say, "Stop!"
473     * output string: He didn\'t say, \"Stop!\"
474     * </pre>
475     *
476     * @param input  String to escape values in, may be null
477     * @return String with escaped values, {@code null} if null string input
478     *
479     * @since 3.0
480     */
481    public static final String escapeEcmaScript(final String input) {
482        return ESCAPE_ECMASCRIPT.translate(input);
483    }
484
485    /**
486     * Escapes the characters in a {@link String} using Json String rules.
487     * <p>Escapes any values it finds into their Json String form.
488     * Deals correctly with quotes and control-chars (tab, backslash, cr, ff, etc.) </p>
489     *
490     * <p>So a tab becomes the characters {@code '\\'} and
491     * {@code 't'}.</p>
492     *
493     * <p>The only difference between Java strings and Json strings
494     * is that in Json, forward-slash (/) is escaped.</p>
495     *
496     * <p>See https://www.ietf.org/rfc/rfc4627.txt for further details.</p>
497     *
498     * <p>Example:</p>
499     * <pre>
500     * input string: He didn't say, "Stop!"
501     * output string: He didn't say, \"Stop!\"
502     * </pre>
503     *
504     * @param input  String to escape values in, may be null
505     * @return String with escaped values, {@code null} if null string input
506     *
507     * @since 3.2
508     */
509    public static final String escapeJson(final String input) {
510        return ESCAPE_JSON.translate(input);
511    }
512
513    /**
514     * Unescapes any Java literals found in the {@link String}.
515     * For example, it will turn a sequence of {@code '\'} and
516     * {@code 'n'} into a newline character, unless the {@code '\'}
517     * is preceded by another {@code '\'}.
518     *
519     * @param input  the {@link String} to unescape, may be null
520     * @return a new unescaped {@link String}, {@code null} if null string input
521     */
522    public static final String unescapeJava(final String input) {
523        return UNESCAPE_JAVA.translate(input);
524    }
525
526    /**
527     * Unescapes any EcmaScript literals found in the {@link String}.
528     *
529     * <p>For example, it will turn a sequence of {@code '\'} and {@code 'n'}
530     * into a newline character, unless the {@code '\'} is preceded by another
531     * {@code '\'}.</p>
532     *
533     * @see #unescapeJava(String)
534     * @param input  the {@link String} to unescape, may be null
535     * @return A new unescaped {@link String}, {@code null} if null string input
536     *
537     * @since 3.0
538     */
539    public static final String unescapeEcmaScript(final String input) {
540        return UNESCAPE_ECMASCRIPT.translate(input);
541    }
542
543    /**
544     * Unescapes any Json literals found in the {@link String}.
545     *
546     * <p>For example, it will turn a sequence of {@code '\'} and {@code 'n'}
547     * into a newline character, unless the {@code '\'} is preceded by another
548     * {@code '\'}.</p>
549     *
550     * @see #unescapeJava(String)
551     * @param input  the {@link String} to unescape, may be null
552     * @return A new unescaped {@link String}, {@code null} if null string input
553     *
554     * @since 3.2
555     */
556    public static final String unescapeJson(final String input) {
557        return UNESCAPE_JSON.translate(input);
558    }
559
560    /**
561     * Escapes the characters in a {@link String} using HTML entities.
562     *
563     * <p>
564     * For example:
565     * </p>
566     * <p>{@code "bread" &amp; "butter"}</p>
567     * becomes:
568     * <p>
569     * {@code &amp;quot;bread&amp;quot; &amp;amp; &amp;quot;butter&amp;quot;}.
570     * </p>
571     *
572     * <p>Supports all known HTML 4.0 entities, including funky accents.
573     * Note that the commonly used apostrophe escape character (&amp;apos;)
574     * is not a legal entity and so is not supported).</p>
575     *
576     * @param input  the {@link String} to escape, may be null
577     * @return a new escaped {@link String}, {@code null} if null string input
578     *
579     * @see <a href="https://web.archive.org/web/20060225074150/https://hotwired.lycos.com/webmonkey/reference/special_characters/">ISO Entities</a>
580     * @see <a href="https://www.w3.org/TR/REC-html32#latin1">HTML 3.2 Character Entities for ISO Latin-1</a>
581     * @see <a href="https://www.w3.org/TR/REC-html40/sgml/entities.html">HTML 4.0 Character entity references</a>
582     * @see <a href="https://www.w3.org/TR/html401/charset.html#h-5.3">HTML 4.01 Character References</a>
583     * @see <a href="https://www.w3.org/TR/html401/charset.html#code-position">HTML 4.01 Code positions</a>
584     *
585     * @since 3.0
586     */
587    public static final String escapeHtml4(final String input) {
588        return ESCAPE_HTML4.translate(input);
589    }
590
591    /**
592     * Escapes the characters in a {@link String} using HTML entities.
593     * <p>Supports only the HTML 3.0 entities.</p>
594     *
595     * @param input  the {@link String} to escape, may be null
596     * @return a new escaped {@link String}, {@code null} if null string input
597     *
598     * @since 3.0
599     */
600    public static final String escapeHtml3(final String input) {
601        return ESCAPE_HTML3.translate(input);
602    }
603
604    /**
605     * Unescapes a string containing entity escapes to a string
606     * containing the actual Unicode characters corresponding to the
607     * escapes. Supports HTML 4.0 entities.
608     *
609     * <p>For example, the string {@code "&lt;Fran&ccedil;ais&gt;"}
610     * will become {@code "<Français>"}</p>
611     *
612     * <p>If an entity is unrecognized, it is left alone, and inserted
613     * verbatim into the result string. e.g. {@code "&gt;&zzzz;x"} will
614     * become {@code ">&zzzz;x"}.</p>
615     *
616     * @param input  the {@link String} to unescape, may be null
617     * @return a new unescaped {@link String}, {@code null} if null string input
618     *
619     * @since 3.0
620     */
621    public static final String unescapeHtml4(final String input) {
622        return UNESCAPE_HTML4.translate(input);
623    }
624
625    /**
626     * Unescapes a string containing entity escapes to a string
627     * containing the actual Unicode characters corresponding to the
628     * escapes. Supports only HTML 3.0 entities.
629     *
630     * @param input  the {@link String} to unescape, may be null
631     * @return a new unescaped {@link String}, {@code null} if null string input
632     *
633     * @since 3.0
634     */
635    public static final String unescapeHtml3(final String input) {
636        return UNESCAPE_HTML3.translate(input);
637    }
638
639    /**
640     * Escapes the characters in a {@link String} using XML entities.
641     *
642     * <p>For example: {@code "bread" & "butter"} =&gt;
643     * {@code &quot;bread&quot; &amp; &quot;butter&quot;}.
644     * </p>
645     *
646     * <p>Supports only the five basic XML entities (gt, lt, quot, amp, apos).
647     * Does not support DTDs or external entities.</p>
648     *
649     * <p>Note that Unicode characters greater than 0x7f are as of 3.0, no longer
650     *    escaped. If you still wish this functionality, you can achieve it
651     *    via the following:
652     * {@code StringEscapeUtils.ESCAPE_XML.with( NumericEntityEscaper.between(0x7f, Integer.MAX_VALUE) );}</p>
653     *
654     * @param input  the {@link String} to escape, may be null
655     * @return a new escaped {@link String}, {@code null} if null string input
656     * @see #unescapeXml(String)
657     * @deprecated use {@link #escapeXml10(java.lang.String)} or {@link #escapeXml11(java.lang.String)} instead.
658     */
659    @Deprecated
660    public static final String escapeXml(final String input) {
661        return ESCAPE_XML.translate(input);
662    }
663
664    /**
665     * Escapes the characters in a {@link String} using XML entities.
666     *
667     * <p>For example: {@code "bread" & "butter"} =&gt;
668     * {@code &quot;bread&quot; &amp; &quot;butter&quot;}.
669     * </p>
670     *
671     * <p>Note that XML 1.0 is a text-only format: it cannot represent control
672     * characters or unpaired Unicode surrogate code points, even after escaping.
673     * {@code escapeXml10} will remove characters that do not fit in the
674     * following ranges:</p>
675     *
676     * <p>{@code #x9 | #xA | #xD | [#x20-#xD7FF] | [#xE000-#xFFFD] | [#x10000-#x10FFFF]}</p>
677     *
678     * <p>Though not strictly necessary, {@code escapeXml10} will escape
679     * characters in the following ranges:</p>
680     *
681     * <p>{@code [#x7F-#x84] | [#x86-#x9F]}</p>
682     *
683     * <p>The returned string can be inserted into a valid XML 1.0 or XML 1.1
684     * document. If you want to allow more non-text characters in an XML 1.1
685     * document, use {@link #escapeXml11(String)}.</p>
686     *
687     * @param input  the {@link String} to escape, may be null
688     * @return a new escaped {@link String}, {@code null} if null string input
689     * @see #unescapeXml(String)
690     * @since 3.3
691     */
692    public static String escapeXml10(final String input) {
693        return ESCAPE_XML10.translate(input);
694    }
695
696    /**
697     * Escapes the characters in a {@link String} using XML entities.
698     *
699     * <p>For example: {@code "bread" & "butter"} =&gt;
700     * {@code &quot;bread&quot; &amp; &quot;butter&quot;}.
701     * </p>
702     *
703     * <p>XML 1.1 can represent certain control characters, but it cannot represent
704     * the null byte or unpaired Unicode surrogate code points, even after escaping.
705     * {@code escapeXml11} will remove characters that do not fit in the following
706     * ranges:</p>
707     *
708     * <p>{@code [#x1-#xD7FF] | [#xE000-#xFFFD] | [#x10000-#x10FFFF]}</p>
709     *
710     * <p>{@code escapeXml11} will escape characters in the following ranges:</p>
711     *
712     * <p>{@code [#x1-#x8] | [#xB-#xC] | [#xE-#x1F] | [#x7F-#x84] | [#x86-#x9F]}</p>
713     *
714     * <p>The returned string can be inserted into a valid XML 1.1 document. Do not
715     * use it for XML 1.0 documents.</p>
716     *
717     * @param input  the {@link String} to escape, may be null
718     * @return a new escaped {@link String}, {@code null} if null string input
719     * @see #unescapeXml(String)
720     * @since 3.3
721     */
722    public static String escapeXml11(final String input) {
723        return ESCAPE_XML11.translate(input);
724    }
725
726    /**
727     * Unescapes a string containing XML entity escapes to a string
728     * containing the actual Unicode characters corresponding to the
729     * escapes.
730     *
731     * <p>Supports only the five basic XML entities (gt, lt, quot, amp, apos).
732     * Does not support DTDs or external entities.</p>
733     *
734     * <p>Note that numerical \\u Unicode codes are unescaped to their respective
735     *    Unicode characters. This may change in future releases.</p>
736     *
737     * @param input  the {@link String} to unescape, may be null
738     * @return a new unescaped {@link String}, {@code null} if null string input
739     * @see #escapeXml(String)
740     * @see #escapeXml10(String)
741     * @see #escapeXml11(String)
742     */
743    public static final String unescapeXml(final String input) {
744        return UNESCAPE_XML.translate(input);
745    }
746
747
748    /**
749     * Returns a {@link String} value for a CSV column enclosed in double quotes,
750     * if required.
751     *
752     * <p>If the value contains a comma, newline or double quote, then the
753     *    String value is returned enclosed in double quotes.</p>
754     *
755     * <p>Any double quote characters in the value are escaped with another double quote.</p>
756     *
757     * <p>If the value does not contain a comma, newline or double quote, then the
758     *    String value is returned unchanged.</p>
759     *
760     * see <a href="https://en.wikipedia.org/wiki/Comma-separated_values">Wikipedia</a> and
761     * <a href="https://datatracker.ietf.org/doc/html/rfc4180">RFC 4180</a>.
762     *
763     * @param input the input CSV column String, may be null
764     * @return the input String, enclosed in double quotes if the value contains a comma,
765     * newline or double quote, {@code null} if null string input
766     * @since 2.4
767     */
768    public static final String escapeCsv(final String input) {
769        return ESCAPE_CSV.translate(input);
770    }
771
772    /**
773     * Returns a {@link String} value for an unescaped CSV column.
774     *
775     * <p>If the value is enclosed in double quotes, and contains a comma, newline
776     *    or double quote, then quotes are removed.
777     * </p>
778     *
779     * <p>Any double quote escaped characters (a pair of double quotes) are unescaped
780     *    to just one double quote.</p>
781     *
782     * <p>If the value is not enclosed in double quotes, or is and does not contain a
783     *    comma, newline or double quote, then the String value is returned unchanged.</p>
784     *
785     * see <a href="https://en.wikipedia.org/wiki/Comma-separated_values">Wikipedia</a> and
786     * <a href="https://datatracker.ietf.org/doc/html/rfc4180">RFC 4180</a>.
787     *
788     * @param input the input CSV column String, may be null
789     * @return the input String, with enclosing double quotes removed and embedded double
790     * quotes unescaped, {@code null} if null string input
791     * @since 2.4
792     */
793    public static final String unescapeCsv(final String input) {
794        return UNESCAPE_CSV.translate(input);
795    }
796
797}