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.util.regex.Matcher;
20 import java.util.regex.Pattern;
21
22 /**
23 * Helpers to process Strings using regular expressions.
24 * @see java.util.regex.Pattern
25 * @since 3.8
26 */
27 public class RegExUtils {
28
29 /**
30 * Compiles the given regular expression into a pattern with the {@link Pattern#DOTALL} flag.
31 *
32 * @param regex The expression to be compiled
33 * @return the given regular expression compiled into a pattern with the {@link Pattern#DOTALL} flag.
34 * @since 3.13.0
35 */
36 public static Pattern dotAll(final String regex) {
37 return Pattern.compile(regex, Pattern.DOTALL);
38 }
39
40 /**
41 * Compiles the given regular expression into a pattern with the {@link Pattern#DOTALL} flag, then creates a matcher that will match the given text against
42 * this pattern.
43 *
44 * @param regex The expression to be compiled.
45 * @param text The character sequence to be matched.
46 * @return A new matcher for this pattern.
47 * @since 3.13.0
48 */
49 public static Matcher dotAllMatcher(final String regex, final String text) {
50 return dotAll(regex).matcher(text);
51 }
52
53 /**
54 * Removes each substring of the text String that matches the given regular expression pattern.
55 *
56 * This method is a {@code null} safe equivalent to:
57 * <ul>
58 * <li>{@code pattern.matcher(text).replaceAll(StringUtils.EMPTY)}</li>
59 * </ul>
60 *
61 * <p>A {@code null} reference passed to this method is a no-op.</p>
62 *
63 * <pre>
64 * StringUtils.removeAll(null, *) = null
65 * StringUtils.removeAll("any", (Pattern) null) = "any"
66 * StringUtils.removeAll("any", Pattern.compile("")) = "any"
67 * StringUtils.removeAll("any", Pattern.compile(".*")) = ""
68 * StringUtils.removeAll("any", Pattern.compile(".+")) = ""
69 * StringUtils.removeAll("abc", Pattern.compile(".?")) = ""
70 * StringUtils.removeAll("A<__>\n<__>B", Pattern.compile("<.*>")) = "A\nB"
71 * StringUtils.removeAll("A<__>\n<__>B", Pattern.compile("(?s)<.*>")) = "AB"
72 * StringUtils.removeAll("A<__>\n<__>B", Pattern.compile("<.*>", Pattern.DOTALL)) = "AB"
73 * StringUtils.removeAll("ABCabc123abc", Pattern.compile("[a-z]")) = "ABC123"
74 * </pre>
75 *
76 * @param text text to remove from, may be null
77 * @param regex the regular expression to which this string is to be matched
78 * @return the text with any removes processed,
79 * {@code null} if null String input
80 *
81 * @see #replaceAll(String, Pattern, String)
82 * @see java.util.regex.Matcher#replaceAll(String)
83 * @see java.util.regex.Pattern
84 */
85 public static String removeAll(final String text, final Pattern regex) {
86 return replaceAll(text, regex, StringUtils.EMPTY);
87 }
88
89 /**
90 * Removes each substring of the text String that matches the given regular expression.
91 *
92 * This method is a {@code null} safe equivalent to:
93 * <ul>
94 * <li>{@code text.replaceAll(regex, StringUtils.EMPTY)}</li>
95 * <li>{@code Pattern.compile(regex).matcher(text).replaceAll(StringUtils.EMPTY)}</li>
96 * </ul>
97 *
98 * <p>A {@code null} reference passed to this method is a no-op.</p>
99 *
100 * <p>Unlike in the {@link #removePattern(String, String)} method, the {@link Pattern#DOTALL} option
101 * is NOT automatically added.
102 * To use the DOTALL option prepend {@code "(?s)"} to the regex.
103 * DOTALL is also known as single-line mode in Perl.</p>
104 *
105 * <pre>
106 * StringUtils.removeAll(null, *) = null
107 * StringUtils.removeAll("any", (String) null) = "any"
108 * StringUtils.removeAll("any", "") = "any"
109 * StringUtils.removeAll("any", ".*") = ""
110 * StringUtils.removeAll("any", ".+") = ""
111 * StringUtils.removeAll("abc", ".?") = ""
112 * StringUtils.removeAll("A<__>\n<__>B", "<.*>") = "A\nB"
113 * StringUtils.removeAll("A<__>\n<__>B", "(?s)<.*>") = "AB"
114 * StringUtils.removeAll("ABCabc123abc", "[a-z]") = "ABC123"
115 * </pre>
116 *
117 * @param text text to remove from, may be null
118 * @param regex the regular expression to which this string is to be matched
119 * @return the text with any removes processed,
120 * {@code null} if null String input
121 *
122 * @throws java.util.regex.PatternSyntaxException
123 * if the regular expression's syntax is invalid
124 *
125 * @see #replaceAll(String, String, String)
126 * @see #removePattern(String, String)
127 * @see String#replaceAll(String, String)
128 * @see java.util.regex.Pattern
129 * @see java.util.regex.Pattern#DOTALL
130 */
131 public static String removeAll(final String text, final String regex) {
132 return replaceAll(text, regex, StringUtils.EMPTY);
133 }
134
135 /**
136 * Removes the first substring of the text string that matches the given regular expression pattern.
137 *
138 * This method is a {@code null} safe equivalent to:
139 * <ul>
140 * <li>{@code pattern.matcher(text).replaceFirst(StringUtils.EMPTY)}</li>
141 * </ul>
142 *
143 * <p>A {@code null} reference passed to this method is a no-op.</p>
144 *
145 * <pre>
146 * StringUtils.removeFirst(null, *) = null
147 * StringUtils.removeFirst("any", (Pattern) null) = "any"
148 * StringUtils.removeFirst("any", Pattern.compile("")) = "any"
149 * StringUtils.removeFirst("any", Pattern.compile(".*")) = ""
150 * StringUtils.removeFirst("any", Pattern.compile(".+")) = ""
151 * StringUtils.removeFirst("abc", Pattern.compile(".?")) = "bc"
152 * StringUtils.removeFirst("A<__>\n<__>B", Pattern.compile("<.*>")) = "A\n<__>B"
153 * StringUtils.removeFirst("A<__>\n<__>B", Pattern.compile("(?s)<.*>")) = "AB"
154 * StringUtils.removeFirst("ABCabc123", Pattern.compile("[a-z]")) = "ABCbc123"
155 * StringUtils.removeFirst("ABCabc123abc", Pattern.compile("[a-z]+")) = "ABC123abc"
156 * </pre>
157 *
158 * @param text text to remove from, may be null
159 * @param regex the regular expression pattern to which this string is to be matched
160 * @return the text with the first replacement processed,
161 * {@code null} if null String input
162 *
163 * @see #replaceFirst(String, Pattern, String)
164 * @see java.util.regex.Matcher#replaceFirst(String)
165 * @see java.util.regex.Pattern
166 */
167 public static String removeFirst(final String text, final Pattern regex) {
168 return replaceFirst(text, regex, StringUtils.EMPTY);
169 }
170
171 /**
172 * Removes the first substring of the text string that matches the given regular expression.
173 *
174 * This method is a {@code null} safe equivalent to:
175 * <ul>
176 * <li>{@code text.replaceFirst(regex, StringUtils.EMPTY)}</li>
177 * <li>{@code Pattern.compile(regex).matcher(text).replaceFirst(StringUtils.EMPTY)}</li>
178 * </ul>
179 *
180 * <p>A {@code null} reference passed to this method is a no-op.</p>
181 *
182 * <p>The {@link Pattern#DOTALL} option is NOT automatically added.
183 * To use the DOTALL option prepend {@code "(?s)"} to the regex.
184 * DOTALL is also known as single-line mode in Perl.</p>
185 *
186 * <pre>
187 * StringUtils.removeFirst(null, *) = null
188 * StringUtils.removeFirst("any", (String) null) = "any"
189 * StringUtils.removeFirst("any", "") = "any"
190 * StringUtils.removeFirst("any", ".*") = ""
191 * StringUtils.removeFirst("any", ".+") = ""
192 * StringUtils.removeFirst("abc", ".?") = "bc"
193 * StringUtils.removeFirst("A<__>\n<__>B", "<.*>") = "A\n<__>B"
194 * StringUtils.removeFirst("A<__>\n<__>B", "(?s)<.*>") = "AB"
195 * StringUtils.removeFirst("ABCabc123", "[a-z]") = "ABCbc123"
196 * StringUtils.removeFirst("ABCabc123abc", "[a-z]+") = "ABC123abc"
197 * </pre>
198 *
199 * @param text text to remove from, may be null
200 * @param regex the regular expression to which this string is to be matched
201 * @return the text with the first replacement processed,
202 * {@code null} if null String input
203 *
204 * @throws java.util.regex.PatternSyntaxException
205 * if the regular expression's syntax is invalid
206 *
207 * @see #replaceFirst(String, String, String)
208 * @see String#replaceFirst(String, String)
209 * @see java.util.regex.Pattern
210 * @see java.util.regex.Pattern#DOTALL
211 */
212 public static String removeFirst(final String text, final String regex) {
213 return replaceFirst(text, regex, StringUtils.EMPTY);
214 }
215
216 /**
217 * Removes each substring of the source String that matches the given regular expression using the DOTALL option.
218 *
219 * This call is a {@code null} safe equivalent to:
220 * <ul>
221 * <li>{@code text.replaceAll("(?s)" + regex, StringUtils.EMPTY)}</li>
222 * <li>{@code Pattern.compile(regex, Pattern.DOTALL).matcher(text).replaceAll(StringUtils.EMPTY)}</li>
223 * </ul>
224 *
225 * <p>A {@code null} reference passed to this method is a no-op.</p>
226 *
227 * <pre>
228 * StringUtils.removePattern(null, *) = null
229 * StringUtils.removePattern("any", (String) null) = "any"
230 * StringUtils.removePattern("A<__>\n<__>B", "<.*>") = "AB"
231 * StringUtils.removePattern("ABCabc123", "[a-z]") = "ABC123"
232 * </pre>
233 *
234 * @param text
235 * the source string
236 * @param regex
237 * the regular expression to which this string is to be matched
238 * @return The resulting {@link String}
239 * @see #replacePattern(String, String, String)
240 * @see String#replaceAll(String, String)
241 * @see Pattern#DOTALL
242 */
243 public static String removePattern(final String text, final String regex) {
244 return replacePattern(text, regex, StringUtils.EMPTY);
245 }
246
247 /**
248 * Replaces each substring of the text String that matches the given regular expression pattern with the given replacement.
249 *
250 * This method is a {@code null} safe equivalent to:
251 * <ul>
252 * <li>{@code pattern.matcher(text).replaceAll(replacement)}</li>
253 * </ul>
254 *
255 * <p>A {@code null} reference passed to this method is a no-op.</p>
256 *
257 * <pre>
258 * StringUtils.replaceAll(null, *, *) = null
259 * StringUtils.replaceAll("any", (Pattern) null, *) = "any"
260 * StringUtils.replaceAll("any", *, null) = "any"
261 * StringUtils.replaceAll("", Pattern.compile(""), "zzz") = "zzz"
262 * StringUtils.replaceAll("", Pattern.compile(".*"), "zzz") = "zzz"
263 * StringUtils.replaceAll("", Pattern.compile(".+"), "zzz") = ""
264 * StringUtils.replaceAll("abc", Pattern.compile(""), "ZZ") = "ZZaZZbZZcZZ"
265 * StringUtils.replaceAll("<__>\n<__>", Pattern.compile("<.*>"), "z") = "z\nz"
266 * StringUtils.replaceAll("<__>\n<__>", Pattern.compile("<.*>", Pattern.DOTALL), "z") = "z"
267 * StringUtils.replaceAll("<__>\n<__>", Pattern.compile("(?s)<.*>"), "z") = "z"
268 * StringUtils.replaceAll("ABCabc123", Pattern.compile("[a-z]"), "_") = "ABC___123"
269 * StringUtils.replaceAll("ABCabc123", Pattern.compile("[^A-Z0-9]+"), "_") = "ABC_123"
270 * StringUtils.replaceAll("ABCabc123", Pattern.compile("[^A-Z0-9]+"), "") = "ABC123"
271 * StringUtils.replaceAll("Lorem ipsum dolor sit", Pattern.compile("( +)([a-z]+)"), "_$2") = "Lorem_ipsum_dolor_sit"
272 * </pre>
273 *
274 * @param text text to search and replace in, may be null
275 * @param regex the regular expression pattern to which this string is to be matched
276 * @param replacement the string to be substituted for each match
277 * @return the text with any replacements processed,
278 * {@code null} if null String input
279 *
280 * @see java.util.regex.Matcher#replaceAll(String)
281 * @see java.util.regex.Pattern
282 */
283 public static String replaceAll(final String text, final Pattern regex, final String replacement) {
284 if (ObjectUtils.anyNull(text, regex, replacement)) {
285 return text;
286 }
287 return regex.matcher(text).replaceAll(replacement);
288 }
289
290 /**
291 * Replaces each substring of the text String that matches the given regular expression
292 * with the given replacement.
293 *
294 * This method is a {@code null} safe equivalent to:
295 * <ul>
296 * <li>{@code text.replaceAll(regex, replacement)}</li>
297 * <li>{@code Pattern.compile(regex).matcher(text).replaceAll(replacement)}</li>
298 * </ul>
299 *
300 * <p>A {@code null} reference passed to this method is a no-op.</p>
301 *
302 * <p>Unlike in the {@link #replacePattern(String, String, String)} method, the {@link Pattern#DOTALL} option
303 * is NOT automatically added.
304 * To use the DOTALL option prepend {@code "(?s)"} to the regex.
305 * DOTALL is also known as single-line mode in Perl.</p>
306 *
307 * <pre>
308 * StringUtils.replaceAll(null, *, *) = null
309 * StringUtils.replaceAll("any", (String) null, *) = "any"
310 * StringUtils.replaceAll("any", *, null) = "any"
311 * StringUtils.replaceAll("", "", "zzz") = "zzz"
312 * StringUtils.replaceAll("", ".*", "zzz") = "zzz"
313 * StringUtils.replaceAll("", ".+", "zzz") = ""
314 * StringUtils.replaceAll("abc", "", "ZZ") = "ZZaZZbZZcZZ"
315 * StringUtils.replaceAll("<__>\n<__>", "<.*>", "z") = "z\nz"
316 * StringUtils.replaceAll("<__>\n<__>", "(?s)<.*>", "z") = "z"
317 * StringUtils.replaceAll("ABCabc123", "[a-z]", "_") = "ABC___123"
318 * StringUtils.replaceAll("ABCabc123", "[^A-Z0-9]+", "_") = "ABC_123"
319 * StringUtils.replaceAll("ABCabc123", "[^A-Z0-9]+", "") = "ABC123"
320 * StringUtils.replaceAll("Lorem ipsum dolor sit", "( +)([a-z]+)", "_$2") = "Lorem_ipsum_dolor_sit"
321 * </pre>
322 *
323 * @param text text to search and replace in, may be null
324 * @param regex the regular expression to which this string is to be matched
325 * @param replacement the string to be substituted for each match
326 * @return the text with any replacements processed,
327 * {@code null} if null String input
328 *
329 * @throws java.util.regex.PatternSyntaxException
330 * if the regular expression's syntax is invalid
331 *
332 * @see #replacePattern(String, String, String)
333 * @see String#replaceAll(String, String)
334 * @see java.util.regex.Pattern
335 * @see java.util.regex.Pattern#DOTALL
336 */
337 public static String replaceAll(final String text, final String regex, final String replacement) {
338 if (ObjectUtils.anyNull(text, regex, replacement)) {
339 return text;
340 }
341 return text.replaceAll(regex, replacement);
342 }
343
344 /**
345 * Replaces the first substring of the text string that matches the given regular expression pattern
346 * with the given replacement.
347 *
348 * This method is a {@code null} safe equivalent to:
349 * <ul>
350 * <li>{@code pattern.matcher(text).replaceFirst(replacement)}</li>
351 * </ul>
352 *
353 * <p>A {@code null} reference passed to this method is a no-op.</p>
354 *
355 * <pre>
356 * StringUtils.replaceFirst(null, *, *) = null
357 * StringUtils.replaceFirst("any", (Pattern) null, *) = "any"
358 * StringUtils.replaceFirst("any", *, null) = "any"
359 * StringUtils.replaceFirst("", Pattern.compile(""), "zzz") = "zzz"
360 * StringUtils.replaceFirst("", Pattern.compile(".*"), "zzz") = "zzz"
361 * StringUtils.replaceFirst("", Pattern.compile(".+"), "zzz") = ""
362 * StringUtils.replaceFirst("abc", Pattern.compile(""), "ZZ") = "ZZabc"
363 * StringUtils.replaceFirst("<__>\n<__>", Pattern.compile("<.*>"), "z") = "z\n<__>"
364 * StringUtils.replaceFirst("<__>\n<__>", Pattern.compile("(?s)<.*>"), "z") = "z"
365 * StringUtils.replaceFirst("ABCabc123", Pattern.compile("[a-z]"), "_") = "ABC_bc123"
366 * StringUtils.replaceFirst("ABCabc123abc", Pattern.compile("[^A-Z0-9]+"), "_") = "ABC_123abc"
367 * StringUtils.replaceFirst("ABCabc123abc", Pattern.compile("[^A-Z0-9]+"), "") = "ABC123abc"
368 * StringUtils.replaceFirst("Lorem ipsum dolor sit", Pattern.compile("( +)([a-z]+)"), "_$2") = "Lorem_ipsum dolor sit"
369 * </pre>
370 *
371 * @param text text to search and replace in, may be null
372 * @param regex the regular expression pattern to which this string is to be matched
373 * @param replacement the string to be substituted for the first match
374 * @return the text with the first replacement processed,
375 * {@code null} if null String input
376 *
377 * @see java.util.regex.Matcher#replaceFirst(String)
378 * @see java.util.regex.Pattern
379 */
380 public static String replaceFirst(final String text, final Pattern regex, final String replacement) {
381 if (text == null || regex == null || replacement == null) {
382 return text;
383 }
384 return regex.matcher(text).replaceFirst(replacement);
385 }
386
387 /**
388 * Replaces the first substring of the text string that matches the given regular expression
389 * with the given replacement.
390 *
391 * This method is a {@code null} safe equivalent to:
392 * <ul>
393 * <li>{@code text.replaceFirst(regex, replacement)}</li>
394 * <li>{@code Pattern.compile(regex).matcher(text).replaceFirst(replacement)}</li>
395 * </ul>
396 *
397 * <p>A {@code null} reference passed to this method is a no-op.</p>
398 *
399 * <p>The {@link Pattern#DOTALL} option is NOT automatically added.
400 * To use the DOTALL option prepend {@code "(?s)"} to the regex.
401 * DOTALL is also known as single-line mode in Perl.</p>
402 *
403 * <pre>
404 * StringUtils.replaceFirst(null, *, *) = null
405 * StringUtils.replaceFirst("any", (String) null, *) = "any"
406 * StringUtils.replaceFirst("any", *, null) = "any"
407 * StringUtils.replaceFirst("", "", "zzz") = "zzz"
408 * StringUtils.replaceFirst("", ".*", "zzz") = "zzz"
409 * StringUtils.replaceFirst("", ".+", "zzz") = ""
410 * StringUtils.replaceFirst("abc", "", "ZZ") = "ZZabc"
411 * StringUtils.replaceFirst("<__>\n<__>", "<.*>", "z") = "z\n<__>"
412 * StringUtils.replaceFirst("<__>\n<__>", "(?s)<.*>", "z") = "z"
413 * StringUtils.replaceFirst("ABCabc123", "[a-z]", "_") = "ABC_bc123"
414 * StringUtils.replaceFirst("ABCabc123abc", "[^A-Z0-9]+", "_") = "ABC_123abc"
415 * StringUtils.replaceFirst("ABCabc123abc", "[^A-Z0-9]+", "") = "ABC123abc"
416 * StringUtils.replaceFirst("Lorem ipsum dolor sit", "( +)([a-z]+)", "_$2") = "Lorem_ipsum dolor sit"
417 * </pre>
418 *
419 * @param text text to search and replace in, may be null
420 * @param regex the regular expression to which this string is to be matched
421 * @param replacement the string to be substituted for the first match
422 * @return the text with the first replacement processed,
423 * {@code null} if null String input
424 *
425 * @throws java.util.regex.PatternSyntaxException
426 * if the regular expression's syntax is invalid
427 *
428 * @see String#replaceFirst(String, String)
429 * @see java.util.regex.Pattern
430 * @see java.util.regex.Pattern#DOTALL
431 */
432 public static String replaceFirst(final String text, final String regex, final String replacement) {
433 if (text == null || regex == null || replacement == null) {
434 return text;
435 }
436 return text.replaceFirst(regex, replacement);
437 }
438
439 /**
440 * Replaces each substring of the source String that matches the given regular expression with the given
441 * replacement using the {@link Pattern#DOTALL} option. DOTALL is also known as single-line mode in Perl.
442 *
443 * This call is a {@code null} safe equivalent to:
444 * <ul>
445 * <li>{@code text.replaceAll("(?s)" + regex, replacement)}</li>
446 * <li>{@code Pattern.compile(regex, Pattern.DOTALL).matcher(text).replaceAll(replacement)}</li>
447 * </ul>
448 *
449 * <p>A {@code null} reference passed to this method is a no-op.</p>
450 *
451 * <pre>
452 * StringUtils.replacePattern(null, *, *) = null
453 * StringUtils.replacePattern("any", (String) null, *) = "any"
454 * StringUtils.replacePattern("any", *, null) = "any"
455 * StringUtils.replacePattern("", "", "zzz") = "zzz"
456 * StringUtils.replacePattern("", ".*", "zzz") = "zzz"
457 * StringUtils.replacePattern("", ".+", "zzz") = ""
458 * StringUtils.replacePattern("<__>\n<__>", "<.*>", "z") = "z"
459 * StringUtils.replacePattern("ABCabc123", "[a-z]", "_") = "ABC___123"
460 * StringUtils.replacePattern("ABCabc123", "[^A-Z0-9]+", "_") = "ABC_123"
461 * StringUtils.replacePattern("ABCabc123", "[^A-Z0-9]+", "") = "ABC123"
462 * StringUtils.replacePattern("Lorem ipsum dolor sit", "( +)([a-z]+)", "_$2") = "Lorem_ipsum_dolor_sit"
463 * </pre>
464 *
465 * @param text
466 * the source string
467 * @param regex
468 * the regular expression to which this string is to be matched
469 * @param replacement
470 * the string to be substituted for each match
471 * @return The resulting {@link String}
472 * @see #replaceAll(String, String, String)
473 * @see String#replaceAll(String, String)
474 * @see Pattern#DOTALL
475 */
476 public static String replacePattern(final String text, final String regex, final String replacement) {
477 if (ObjectUtils.anyNull(text, regex, replacement)) {
478 return text;
479 }
480 return dotAllMatcher(regex, text).replaceAll(replacement);
481 }
482
483 }