View Javadoc
1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.lang3;
18  
19  import java.io.IOException;
20  import java.io.Writer;
21  
22  import org.apache.commons.lang3.text.translate.AggregateTranslator;
23  import org.apache.commons.lang3.text.translate.CharSequenceTranslator;
24  import org.apache.commons.lang3.text.translate.EntityArrays;
25  import org.apache.commons.lang3.text.translate.JavaUnicodeEscaper;
26  import org.apache.commons.lang3.text.translate.LookupTranslator;
27  import org.apache.commons.lang3.text.translate.NumericEntityEscaper;
28  import org.apache.commons.lang3.text.translate.NumericEntityUnescaper;
29  import org.apache.commons.lang3.text.translate.OctalUnescaper;
30  import org.apache.commons.lang3.text.translate.UnicodeUnescaper;
31  import org.apache.commons.lang3.text.translate.UnicodeUnpairedSurrogateRemover;
32  
33  /**
34   * <p>Escapes and unescapes {@code String}s for
35   * Java, Java Script, HTML and XML.</p>
36   *
37   * <p>#ThreadSafe#</p>
38   * @since 2.0
39   * @deprecated as of 3.6, use commons-text
40   * <a href="https://commons.apache.org/proper/commons-text/javadocs/api-release/org/apache/commons/text/StringEscapeUtils.html">
41   * StringEscapeUtils</a> instead
42   */
43  @Deprecated
44  public class StringEscapeUtils {
45  
46      /* ESCAPE TRANSLATORS */
47  
48      /**
49       * Translator object for escaping Java.
50       *
51       * While {@link #escapeJava(String)} is the expected method of use, this
52       * object allows the Java escaping functionality to be used
53       * as the foundation for a custom translator.
54       *
55       * @since 3.0
56       */
57      public static final CharSequenceTranslator ESCAPE_JAVA =
58            new LookupTranslator(
59              new String[][] {
60                {"\"", "\\\""},
61                {"\\", "\\\\"},
62            }).with(
63              new LookupTranslator(EntityArrays.JAVA_CTRL_CHARS_ESCAPE())
64            ).with(
65              JavaUnicodeEscaper.outsideOf(32, 0x7f)
66          );
67  
68      /**
69       * Translator object for escaping EcmaScript/JavaScript.
70       *
71       * While {@link #escapeEcmaScript(String)} is the expected method of use, this
72       * object allows the EcmaScript escaping functionality to be used
73       * as the foundation for a custom translator.
74       *
75       * @since 3.0
76       */
77      public static final CharSequenceTranslator ESCAPE_ECMASCRIPT =
78          new AggregateTranslator(
79              new LookupTranslator(
80                        new String[][] {
81                              {"'", "\\'"},
82                              {"\"", "\\\""},
83                              {"\\", "\\\\"},
84                              {"/", "\\/"}
85                        }),
86              new LookupTranslator(EntityArrays.JAVA_CTRL_CHARS_ESCAPE()),
87              JavaUnicodeEscaper.outsideOf(32, 0x7f)
88          );
89  
90      /**
91       * Translator object for escaping Json.
92       *
93       * While {@link #escapeJson(String)} is the expected method of use, this
94       * object allows the Json escaping functionality to be used
95       * as the foundation for a custom translator.
96       *
97       * @since 3.2
98       */
99      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      * <p>{@code StringEscapeUtils} instances should NOT be constructed in
422      * standard programming.</p>
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     // Java and JavaScript
434     //--------------------------------------------------------------------------
435     /**
436      * <p>Escapes the characters in a {@code String} using Java String rules.</p>
437      *
438      * <p>Deals correctly with quotes and control-chars (tab, backslash, cr, ff, etc.) </p>
439      *
440      * <p>So a tab becomes the characters {@code '\\'} and
441      * {@code 't'}.</p>
442      *
443      * <p>The only difference between Java strings and JavaScript strings
444      * is that in JavaScript, a single quote and forward-slash (/) are escaped.</p>
445      *
446      * <p>Example:</p>
447      * <pre>
448      * input string: He didn't say, "Stop!"
449      * output string: He didn't say, \"Stop!\"
450      * </pre>
451      *
452      * @param input  String to escape values in, may be null
453      * @return String with escaped values, {@code null} if null string input
454      */
455     public static final String escapeJava(final String input) {
456         return ESCAPE_JAVA.translate(input);
457     }
458 
459     /**
460      * <p>Escapes the characters in a {@code String} using EcmaScript String rules.</p>
461      * <p>Escapes any values it finds into their EcmaScript String form.
462      * Deals correctly with quotes and control-chars (tab, backslash, cr, ff, etc.) </p>
463      *
464      * <p>So a tab becomes the characters {@code '\\'} and
465      * {@code 't'}.</p>
466      *
467      * <p>The only difference between Java strings and EcmaScript strings
468      * is that in EcmaScript, a single quote and forward-slash (/) are escaped.</p>
469      *
470      * <p>Note that EcmaScript is best known by the JavaScript and ActionScript dialects. </p>
471      *
472      * <p>Example:</p>
473      * <pre>
474      * input string: He didn't say, "Stop!"
475      * output string: He didn\'t say, \"Stop!\"
476      * </pre>
477      *
478      * @param input  String to escape values in, may be null
479      * @return String with escaped values, {@code null} if null string input
480      *
481      * @since 3.0
482      */
483     public static final String escapeEcmaScript(final String input) {
484         return ESCAPE_ECMASCRIPT.translate(input);
485     }
486 
487     /**
488      * <p>Escapes the characters in a {@code String} using Json String rules.</p>
489      * <p>Escapes any values it finds into their Json String form.
490      * Deals correctly with quotes and control-chars (tab, backslash, cr, ff, etc.) </p>
491      *
492      * <p>So a tab becomes the characters {@code '\\'} and
493      * {@code 't'}.</p>
494      *
495      * <p>The only difference between Java strings and Json strings
496      * is that in Json, forward-slash (/) is escaped.</p>
497      *
498      * <p>See http://www.ietf.org/rfc/rfc4627.txt for further details. </p>
499      *
500      * <p>Example:</p>
501      * <pre>
502      * input string: He didn't say, "Stop!"
503      * output string: He didn't say, \"Stop!\"
504      * </pre>
505      *
506      * @param input  String to escape values in, may be null
507      * @return String with escaped values, {@code null} if null string input
508      *
509      * @since 3.2
510      */
511     public static final String escapeJson(final String input) {
512         return ESCAPE_JSON.translate(input);
513     }
514 
515     /**
516      * <p>Unescapes any Java literals found in the {@code String}.
517      * For example, it will turn a sequence of {@code '\'} and
518      * {@code 'n'} into a newline character, unless the {@code '\'}
519      * is preceded by another {@code '\'}.</p>
520      *
521      * @param input  the {@code String} to unescape, may be null
522      * @return a new unescaped {@code String}, {@code null} if null string input
523      */
524     public static final String unescapeJava(final String input) {
525         return UNESCAPE_JAVA.translate(input);
526     }
527 
528     /**
529      * <p>Unescapes any EcmaScript literals found in the {@code String}.</p>
530      *
531      * <p>For example, it will turn a sequence of {@code '\'} and {@code 'n'}
532      * into a newline character, unless the {@code '\'} is preceded by another
533      * {@code '\'}.</p>
534      *
535      * @see #unescapeJava(String)
536      * @param input  the {@code String} to unescape, may be null
537      * @return A new unescaped {@code String}, {@code null} if null string input
538      *
539      * @since 3.0
540      */
541     public static final String unescapeEcmaScript(final String input) {
542         return UNESCAPE_ECMASCRIPT.translate(input);
543     }
544 
545     /**
546      * <p>Unescapes any Json literals found in the {@code String}.</p>
547      *
548      * <p>For example, it will turn a sequence of {@code '\'} and {@code 'n'}
549      * into a newline character, unless the {@code '\'} is preceded by another
550      * {@code '\'}.</p>
551      *
552      * @see #unescapeJava(String)
553      * @param input  the {@code String} to unescape, may be null
554      * @return A new unescaped {@code String}, {@code null} if null string input
555      *
556      * @since 3.2
557      */
558     public static final String unescapeJson(final String input) {
559         return UNESCAPE_JSON.translate(input);
560     }
561 
562     // HTML and XML
563     //--------------------------------------------------------------------------
564     /**
565      * <p>Escapes the characters in a {@code String} using HTML entities.</p>
566      *
567      * <p>
568      * For example:
569      * </p>
570      * <p>{@code "bread" &amp; "butter"}</p>
571      * becomes:
572      * <p>
573      * {@code &amp;quot;bread&amp;quot; &amp;amp; &amp;quot;butter&amp;quot;}.
574      * </p>
575      *
576      * <p>Supports all known HTML 4.0 entities, including funky accents.
577      * Note that the commonly used apostrophe escape character (&amp;apos;)
578      * is not a legal entity and so is not supported). </p>
579      *
580      * @param input  the {@code String} to escape, may be null
581      * @return a new escaped {@code String}, {@code null} if null string input
582      *
583      * @see <a href="http://hotwired.lycos.com/webmonkey/reference/special_characters/">ISO Entities</a>
584      * @see <a href="http://www.w3.org/TR/REC-html32#latin1">HTML 3.2 Character Entities for ISO Latin-1</a>
585      * @see <a href="http://www.w3.org/TR/REC-html40/sgml/entities.html">HTML 4.0 Character entity references</a>
586      * @see <a href="http://www.w3.org/TR/html401/charset.html#h-5.3">HTML 4.01 Character References</a>
587      * @see <a href="http://www.w3.org/TR/html401/charset.html#code-position">HTML 4.01 Code positions</a>
588      *
589      * @since 3.0
590      */
591     public static final String escapeHtml4(final String input) {
592         return ESCAPE_HTML4.translate(input);
593     }
594 
595     /**
596      * <p>Escapes the characters in a {@code String} using HTML entities.</p>
597      * <p>Supports only the HTML 3.0 entities. </p>
598      *
599      * @param input  the {@code String} to escape, may be null
600      * @return a new escaped {@code String}, {@code null} if null string input
601      *
602      * @since 3.0
603      */
604     public static final String escapeHtml3(final String input) {
605         return ESCAPE_HTML3.translate(input);
606     }
607 
608     //-----------------------------------------------------------------------
609     /**
610      * <p>Unescapes a string containing entity escapes to a string
611      * containing the actual Unicode characters corresponding to the
612      * escapes. Supports HTML 4.0 entities.</p>
613      *
614      * <p>For example, the string {@code "&lt;Fran&ccedil;ais&gt;"}
615      * will become {@code "<Français>"}</p>
616      *
617      * <p>If an entity is unrecognized, it is left alone, and inserted
618      * verbatim into the result string. e.g. {@code "&gt;&zzzz;x"} will
619      * become {@code ">&zzzz;x"}.</p>
620      *
621      * @param input  the {@code String} to unescape, may be null
622      * @return a new unescaped {@code String}, {@code null} if null string input
623      *
624      * @since 3.0
625      */
626     public static final String unescapeHtml4(final String input) {
627         return UNESCAPE_HTML4.translate(input);
628     }
629 
630     /**
631      * <p>Unescapes a string containing entity escapes to a string
632      * containing the actual Unicode characters corresponding to the
633      * escapes. Supports only HTML 3.0 entities.</p>
634      *
635      * @param input  the {@code String} to unescape, may be null
636      * @return a new unescaped {@code String}, {@code null} if null string input
637      *
638      * @since 3.0
639      */
640     public static final String unescapeHtml3(final String input) {
641         return UNESCAPE_HTML3.translate(input);
642     }
643 
644     //-----------------------------------------------------------------------
645     /**
646      * <p>Escapes the characters in a {@code String} using XML entities.</p>
647      *
648      * <p>For example: {@code "bread" & "butter"} =&gt;
649      * {@code &quot;bread&quot; &amp; &quot;butter&quot;}.
650      * </p>
651      *
652      * <p>Supports only the five basic XML entities (gt, lt, quot, amp, apos).
653      * Does not support DTDs or external entities.</p>
654      *
655      * <p>Note that Unicode characters greater than 0x7f are as of 3.0, no longer
656      *    escaped. If you still wish this functionality, you can achieve it
657      *    via the following:
658      * {@code StringEscapeUtils.ESCAPE_XML.with( NumericEntityEscaper.between(0x7f, Integer.MAX_VALUE) );}</p>
659      *
660      * @param input  the {@code String} to escape, may be null
661      * @return a new escaped {@code String}, {@code null} if null string input
662      * @see #unescapeXml(java.lang.String)
663      * @deprecated use {@link #escapeXml10(java.lang.String)} or {@link #escapeXml11(java.lang.String)} instead.
664      */
665     @Deprecated
666     public static final String escapeXml(final String input) {
667         return ESCAPE_XML.translate(input);
668     }
669 
670     /**
671      * <p>Escapes the characters in a {@code String} using XML entities.</p>
672      *
673      * <p>For example: {@code "bread" & "butter"} =&gt;
674      * {@code &quot;bread&quot; &amp; &quot;butter&quot;}.
675      * </p>
676      *
677      * <p>Note that XML 1.0 is a text-only format: it cannot represent control
678      * characters or unpaired Unicode surrogate codepoints, even after escaping.
679      * {@code escapeXml10} will remove characters that do not fit in the
680      * following ranges:</p>
681      *
682      * <p>{@code #x9 | #xA | #xD | [#x20-#xD7FF] | [#xE000-#xFFFD] | [#x10000-#x10FFFF]}</p>
683      *
684      * <p>Though not strictly necessary, {@code escapeXml10} will escape
685      * characters in the following ranges:</p>
686      *
687      * <p>{@code [#x7F-#x84] | [#x86-#x9F]}</p>
688      *
689      * <p>The returned string can be inserted into a valid XML 1.0 or XML 1.1
690      * document. If you want to allow more non-text characters in an XML 1.1
691      * document, use {@link #escapeXml11(String)}.</p>
692      *
693      * @param input  the {@code String} to escape, may be null
694      * @return a new escaped {@code String}, {@code null} if null string input
695      * @see #unescapeXml(java.lang.String)
696      * @since 3.3
697      */
698     public static String escapeXml10(final String input) {
699         return ESCAPE_XML10.translate(input);
700     }
701 
702     /**
703      * <p>Escapes the characters in a {@code String} using XML entities.</p>
704      *
705      * <p>For example: {@code "bread" & "butter"} =&gt;
706      * {@code &quot;bread&quot; &amp; &quot;butter&quot;}.
707      * </p>
708      *
709      * <p>XML 1.1 can represent certain control characters, but it cannot represent
710      * the null byte or unpaired Unicode surrogate codepoints, even after escaping.
711      * {@code escapeXml11} will remove characters that do not fit in the following
712      * ranges:</p>
713      *
714      * <p>{@code [#x1-#xD7FF] | [#xE000-#xFFFD] | [#x10000-#x10FFFF]}</p>
715      *
716      * <p>{@code escapeXml11} will escape characters in the following ranges:</p>
717      *
718      * <p>{@code [#x1-#x8] | [#xB-#xC] | [#xE-#x1F] | [#x7F-#x84] | [#x86-#x9F]}</p>
719      *
720      * <p>The returned string can be inserted into a valid XML 1.1 document. Do not
721      * use it for XML 1.0 documents.</p>
722      *
723      * @param input  the {@code String} to escape, may be null
724      * @return a new escaped {@code String}, {@code null} if null string input
725      * @see #unescapeXml(java.lang.String)
726      * @since 3.3
727      */
728     public static String escapeXml11(final String input) {
729         return ESCAPE_XML11.translate(input);
730     }
731 
732     //-----------------------------------------------------------------------
733     /**
734      * <p>Unescapes a string containing XML entity escapes to a string
735      * containing the actual Unicode characters corresponding to the
736      * escapes.</p>
737      *
738      * <p>Supports only the five basic XML entities (gt, lt, quot, amp, apos).
739      * Does not support DTDs or external entities.</p>
740      *
741      * <p>Note that numerical \\u Unicode codes are unescaped to their respective
742      *    Unicode characters. This may change in future releases. </p>
743      *
744      * @param input  the {@code String} to unescape, may be null
745      * @return a new unescaped {@code String}, {@code null} if null string input
746      * @see #escapeXml(String)
747      * @see #escapeXml10(String)
748      * @see #escapeXml11(String)
749      */
750     public static final String unescapeXml(final String input) {
751         return UNESCAPE_XML.translate(input);
752     }
753 
754     //-----------------------------------------------------------------------
755 
756     /**
757      * <p>Returns a {@code String} value for a CSV column enclosed in double quotes,
758      * if required.</p>
759      *
760      * <p>If the value contains a comma, newline or double quote, then the
761      *    String value is returned enclosed in double quotes.</p>
762      *
763      * <p>Any double quote characters in the value are escaped with another double quote.</p>
764      *
765      * <p>If the value does not contain a comma, newline or double quote, then the
766      *    String value is returned unchanged.</p>
767      *
768      * see <a href="http://en.wikipedia.org/wiki/Comma-separated_values">Wikipedia</a> and
769      * <a href="http://tools.ietf.org/html/rfc4180">RFC 4180</a>.
770      *
771      * @param input the input CSV column String, may be null
772      * @return the input String, enclosed in double quotes if the value contains a comma,
773      * newline or double quote, {@code null} if null string input
774      * @since 2.4
775      */
776     public static final String escapeCsv(final String input) {
777         return ESCAPE_CSV.translate(input);
778     }
779 
780     /**
781      * <p>Returns a {@code String} value for an unescaped CSV column. </p>
782      *
783      * <p>If the value is enclosed in double quotes, and contains a comma, newline
784      *    or double quote, then quotes are removed.
785      * </p>
786      *
787      * <p>Any double quote escaped characters (a pair of double quotes) are unescaped
788      *    to just one double quote. </p>
789      *
790      * <p>If the value is not enclosed in double quotes, or is and does not contain a
791      *    comma, newline or double quote, then the String value is returned unchanged.</p>
792      *
793      * see <a href="http://en.wikipedia.org/wiki/Comma-separated_values">Wikipedia</a> and
794      * <a href="http://tools.ietf.org/html/rfc4180">RFC 4180</a>.
795      *
796      * @param input the input CSV column String, may be null
797      * @return the input String, with enclosing double quotes removed and embedded double
798      * quotes unescaped, {@code null} if null string input
799      * @since 2.4
800      */
801     public static final String unescapeCsv(final String input) {
802         return UNESCAPE_CSV.translate(input);
803     }
804 
805 }