1 /*
2 * Copyright 2002-2008 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package org.argeo.osgi.boot.internal.springutil;
18
19 import java.util.ArrayList;
20 import java.util.Arrays;
21 import java.util.Collection;
22 import java.util.Collections;
23 import java.util.Enumeration;
24 import java.util.Iterator;
25 import java.util.LinkedList;
26 import java.util.List;
27 import java.util.Locale;
28 import java.util.Properties;
29 import java.util.Set;
30 import java.util.StringTokenizer;
31 import java.util.TreeSet;
32
33 /**
34 * Miscellaneous {@link String} utility methods.
35 *
36 * <p>Mainly for internal use within the framework; consider
37 * <a href="http://jakarta.apache.org/commons/lang/">Jakarta's Commons Lang</a>
38 * for a more comprehensive suite of String utilities.
39 *
40 * <p>This class delivers some simple functionality that should really
41 * be provided by the core Java <code>String</code> and {@link StringBuffer}
42 * classes, such as the ability to {@link #replace} all occurrences of a given
43 * substring in a target string. It also provides easy-to-use methods to convert
44 * between delimited strings, such as CSV strings, and collections and arrays.
45 *
46 * @author Rod Johnson
47 * @author Juergen Hoeller
48 * @author Keith Donald
49 * @author Rob Harrop
50 * @author Rick Evans
51 * @since 16 April 2001
52 */
53 @SuppressWarnings({ "rawtypes", "unchecked" })
54 public abstract class StringUtils {
55
56 private static final String FOLDER_SEPARATOR = "/";
57
58 private static final String WINDOWS_FOLDER_SEPARATOR = "\\";
59
60 private static final String TOP_PATH = "..";
61
62 private static final String CURRENT_PATH = ".";
63
64 private static final char EXTENSION_SEPARATOR = '.';
65
66
67 //---------------------------------------------------------------------
68 // General convenience methods for working with Strings
69 //---------------------------------------------------------------------
70
71 /**
72 * Check that the given CharSequence is neither <code>null</code> nor of length 0.
73 * Note: Will return <code>true</code> for a CharSequence that purely consists of whitespace.
74 * <p><pre>
75 * StringUtils.hasLength(null) = false
76 * StringUtils.hasLength("") = false
77 * StringUtils.hasLength(" ") = true
78 * StringUtils.hasLength("Hello") = true
79 * </pre>
80 * @param str the CharSequence to check (may be <code>null</code>)
81 * @return <code>true</code> if the CharSequence is not null and has length
82 * @see #hasText(String)
83 */
84 public static boolean hasLength(CharSequence str) {
85 return (str != null && str.length() > 0);
86 }
87
88 /**
89 * Check that the given String is neither <code>null</code> nor of length 0.
90 * Note: Will return <code>true</code> for a String that purely consists of whitespace.
91 * @param str the String to check (may be <code>null</code>)
92 * @return <code>true</code> if the String is not null and has length
93 * @see #hasLength(CharSequence)
94 */
95 public static boolean hasLength(String str) {
96 return hasLength((CharSequence) str);
97 }
98
99 /**
100 * Check whether the given CharSequence has actual text.
101 * More specifically, returns <code>true</code> if the string not <code>null</code>,
102 * its length is greater than 0, and it contains at least one non-whitespace character.
103 * <p><pre>
104 * StringUtils.hasText(null) = false
105 * StringUtils.hasText("") = false
106 * StringUtils.hasText(" ") = false
107 * StringUtils.hasText("12345") = true
108 * StringUtils.hasText(" 12345 ") = true
109 * </pre>
110 * @param str the CharSequence to check (may be <code>null</code>)
111 * @return <code>true</code> if the CharSequence is not <code>null</code>,
112 * its length is greater than 0, and it does not contain whitespace only
113 * @see java.lang.Character#isWhitespace
114 */
115 public static boolean hasText(CharSequence str) {
116 if (!hasLength(str)) {
117 return false;
118 }
119 int strLen = str.length();
120 for (int i = 0; i < strLen; i++) {
121 if (!Character.isWhitespace(str.charAt(i))) {
122 return true;
123 }
124 }
125 return false;
126 }
127
128 /**
129 * Check whether the given String has actual text.
130 * More specifically, returns <code>true</code> if the string not <code>null</code>,
131 * its length is greater than 0, and it contains at least one non-whitespace character.
132 * @param str the String to check (may be <code>null</code>)
133 * @return <code>true</code> if the String is not <code>null</code>, its length is
134 * greater than 0, and it does not contain whitespace only
135 * @see #hasText(CharSequence)
136 */
137 public static boolean hasText(String str) {
138 return hasText((CharSequence) str);
139 }
140
141 /**
142 * Check whether the given CharSequence contains any whitespace characters.
143 * @param str the CharSequence to check (may be <code>null</code>)
144 * @return <code>true</code> if the CharSequence is not empty and
145 * contains at least 1 whitespace character
146 * @see java.lang.Character#isWhitespace
147 */
148 public static boolean containsWhitespace(CharSequence str) {
149 if (!hasLength(str)) {
150 return false;
151 }
152 int strLen = str.length();
153 for (int i = 0; i < strLen; i++) {
154 if (Character.isWhitespace(str.charAt(i))) {
155 return true;
156 }
157 }
158 return false;
159 }
160
161 /**
162 * Check whether the given String contains any whitespace characters.
163 * @param str the String to check (may be <code>null</code>)
164 * @return <code>true</code> if the String is not empty and
165 * contains at least 1 whitespace character
166 * @see #containsWhitespace(CharSequence)
167 */
168 public static boolean containsWhitespace(String str) {
169 return containsWhitespace((CharSequence) str);
170 }
171
172 /**
173 * Trim leading and trailing whitespace from the given String.
174 * @param str the String to check
175 * @return the trimmed String
176 * @see java.lang.Character#isWhitespace
177 */
178 public static String trimWhitespace(String str) {
179 if (!hasLength(str)) {
180 return str;
181 }
182 StringBuffer buf = new StringBuffer(str);
183 while (buf.length() > 0 && Character.isWhitespace(buf.charAt(0))) {
184 buf.deleteCharAt(0);
185 }
186 while (buf.length() > 0 && Character.isWhitespace(buf.charAt(buf.length() - 1))) {
187 buf.deleteCharAt(buf.length() - 1);
188 }
189 return buf.toString();
190 }
191
192 /**
193 * Trim <i>all</i> whitespace from the given String:
194 * leading, trailing, and inbetween characters.
195 * @param str the String to check
196 * @return the trimmed String
197 * @see java.lang.Character#isWhitespace
198 */
199 public static String trimAllWhitespace(String str) {
200 if (!hasLength(str)) {
201 return str;
202 }
203 StringBuffer buf = new StringBuffer(str);
204 int index = 0;
205 while (buf.length() > index) {
206 if (Character.isWhitespace(buf.charAt(index))) {
207 buf.deleteCharAt(index);
208 }
209 else {
210 index++;
211 }
212 }
213 return buf.toString();
214 }
215
216 /**
217 * Trim leading whitespace from the given String.
218 * @param str the String to check
219 * @return the trimmed String
220 * @see java.lang.Character#isWhitespace
221 */
222 public static String trimLeadingWhitespace(String str) {
223 if (!hasLength(str)) {
224 return str;
225 }
226 StringBuffer buf = new StringBuffer(str);
227 while (buf.length() > 0 && Character.isWhitespace(buf.charAt(0))) {
228 buf.deleteCharAt(0);
229 }
230 return buf.toString();
231 }
232
233 /**
234 * Trim trailing whitespace from the given String.
235 * @param str the String to check
236 * @return the trimmed String
237 * @see java.lang.Character#isWhitespace
238 */
239 public static String trimTrailingWhitespace(String str) {
240 if (!hasLength(str)) {
241 return str;
242 }
243 StringBuffer buf = new StringBuffer(str);
244 while (buf.length() > 0 && Character.isWhitespace(buf.charAt(buf.length() - 1))) {
245 buf.deleteCharAt(buf.length() - 1);
246 }
247 return buf.toString();
248 }
249
250 /**
251 * Trim all occurences of the supplied leading character from the given String.
252 * @param str the String to check
253 * @param leadingCharacter the leading character to be trimmed
254 * @return the trimmed String
255 */
256 public static String trimLeadingCharacter(String str, char leadingCharacter) {
257 if (!hasLength(str)) {
258 return str;
259 }
260 StringBuffer buf = new StringBuffer(str);
261 while (buf.length() > 0 && buf.charAt(0) == leadingCharacter) {
262 buf.deleteCharAt(0);
263 }
264 return buf.toString();
265 }
266
267 /**
268 * Trim all occurences of the supplied trailing character from the given String.
269 * @param str the String to check
270 * @param trailingCharacter the trailing character to be trimmed
271 * @return the trimmed String
272 */
273 public static String trimTrailingCharacter(String str, char trailingCharacter) {
274 if (!hasLength(str)) {
275 return str;
276 }
277 StringBuffer buf = new StringBuffer(str);
278 while (buf.length() > 0 && buf.charAt(buf.length() - 1) == trailingCharacter) {
279 buf.deleteCharAt(buf.length() - 1);
280 }
281 return buf.toString();
282 }
283
284
285 /**
286 * Test if the given String starts with the specified prefix,
287 * ignoring upper/lower case.
288 * @param str the String to check
289 * @param prefix the prefix to look for
290 * @see java.lang.String#startsWith
291 */
292 public static boolean startsWithIgnoreCase(String str, String prefix) {
293 if (str == null || prefix == null) {
294 return false;
295 }
296 if (str.startsWith(prefix)) {
297 return true;
298 }
299 if (str.length() < prefix.length()) {
300 return false;
301 }
302 String lcStr = str.substring(0, prefix.length()).toLowerCase();
303 String lcPrefix = prefix.toLowerCase();
304 return lcStr.equals(lcPrefix);
305 }
306
307 /**
308 * Test if the given String ends with the specified suffix,
309 * ignoring upper/lower case.
310 * @param str the String to check
311 * @param suffix the suffix to look for
312 * @see java.lang.String#endsWith
313 */
314 public static boolean endsWithIgnoreCase(String str, String suffix) {
315 if (str == null || suffix == null) {
316 return false;
317 }
318 if (str.endsWith(suffix)) {
319 return true;
320 }
321 if (str.length() < suffix.length()) {
322 return false;
323 }
324
325 String lcStr = str.substring(str.length() - suffix.length()).toLowerCase();
326 String lcSuffix = suffix.toLowerCase();
327 return lcStr.equals(lcSuffix);
328 }
329
330 /**
331 * Test whether the given string matches the given substring
332 * at the given index.
333 * @param str the original string (or StringBuffer)
334 * @param index the index in the original string to start matching against
335 * @param substring the substring to match at the given index
336 */
337 public static boolean substringMatch(CharSequence str, int index, CharSequence substring) {
338 for (int j = 0; j < substring.length(); j++) {
339 int i = index + j;
340 if (i >= str.length() || str.charAt(i) != substring.charAt(j)) {
341 return false;
342 }
343 }
344 return true;
345 }
346
347 /**
348 * Count the occurrences of the substring in string s.
349 * @param str string to search in. Return 0 if this is null.
350 * @param sub string to search for. Return 0 if this is null.
351 */
352 public static int countOccurrencesOf(String str, String sub) {
353 if (str == null || sub == null || str.length() == 0 || sub.length() == 0) {
354 return 0;
355 }
356 int count = 0, pos = 0, idx = 0;
357 while ((idx = str.indexOf(sub, pos)) != -1) {
358 ++count;
359 pos = idx + sub.length();
360 }
361 return count;
362 }
363
364 /**
365 * Replace all occurences of a substring within a string with
366 * another string.
367 * @param inString String to examine
368 * @param oldPattern String to replace
369 * @param newPattern String to insert
370 * @return a String with the replacements
371 */
372 public static String replace(String inString, String oldPattern, String newPattern) {
373 if (!hasLength(inString) || !hasLength(oldPattern) || newPattern == null) {
374 return inString;
375 }
376 StringBuffer sbuf = new StringBuffer();
377 // output StringBuffer we'll build up
378 int pos = 0; // our position in the old string
379 int index = inString.indexOf(oldPattern);
380 // the index of an occurrence we've found, or -1
381 int patLen = oldPattern.length();
382 while (index >= 0) {
383 sbuf.append(inString.substring(pos, index));
384 sbuf.append(newPattern);
385 pos = index + patLen;
386 index = inString.indexOf(oldPattern, pos);
387 }
388 sbuf.append(inString.substring(pos));
389 // remember to append any characters to the right of a match
390 return sbuf.toString();
391 }
392
393 /**
394 * Delete all occurrences of the given substring.
395 * @param inString the original String
396 * @param pattern the pattern to delete all occurrences of
397 * @return the resulting String
398 */
399 public static String delete(String inString, String pattern) {
400 return replace(inString, pattern, "");
401 }
402
403 /**
404 * Delete any character in a given String.
405 * @param inString the original String
406 * @param charsToDelete a set of characters to delete.
407 * E.g. "az\n" will delete 'a's, 'z's and new lines.
408 * @return the resulting String
409 */
410 public static String deleteAny(String inString, String charsToDelete) {
411 if (!hasLength(inString) || !hasLength(charsToDelete)) {
412 return inString;
413 }
414 StringBuffer out = new StringBuffer();
415 for (int i = 0; i < inString.length(); i++) {
416 char c = inString.charAt(i);
417 if (charsToDelete.indexOf(c) == -1) {
418 out.append(c);
419 }
420 }
421 return out.toString();
422 }
423
424
425 //---------------------------------------------------------------------
426 // Convenience methods for working with formatted Strings
427 //---------------------------------------------------------------------
428
429 /**
430 * Quote the given String with single quotes.
431 * @param str the input String (e.g. "myString")
432 * @return the quoted String (e.g. "'myString'"),
433 * or <code>null</code> if the input was <code>null</code>
434 */
435 public static String quote(String str) {
436 return (str != null ? "'" + str + "'" : null);
437 }
438
439 /**
440 * Turn the given Object into a String with single quotes
441 * if it is a String; keeping the Object as-is else.
442 * @param obj the input Object (e.g. "myString")
443 * @return the quoted String (e.g. "'myString'"),
444 * or the input object as-is if not a String
445 */
446 public static Object quoteIfString(Object obj) {
447 return (obj instanceof String ? quote((String) obj) : obj);
448 }
449
450 /**
451 * Unqualify a string qualified by a '.' dot character. For example,
452 * "this.name.is.qualified", returns "qualified".
453 * @param qualifiedName the qualified name
454 */
455 public static String unqualify(String qualifiedName) {
456 return unqualify(qualifiedName, '.');
457 }
458
459 /**
460 * Unqualify a string qualified by a separator character. For example,
461 * "this:name:is:qualified" returns "qualified" if using a ':' separator.
462 * @param qualifiedName the qualified name
463 * @param separator the separator
464 */
465 public static String unqualify(String qualifiedName, char separator) {
466 return qualifiedName.substring(qualifiedName.lastIndexOf(separator) + 1);
467 }
468
469 /**
470 * Capitalize a <code>String</code>, changing the first letter to
471 * upper case as per {@link Character#toUpperCase(char)}.
472 * No other letters are changed.
473 * @param str the String to capitalize, may be <code>null</code>
474 * @return the capitalized String, <code>null</code> if null
475 */
476 public static String capitalize(String str) {
477 return changeFirstCharacterCase(str, true);
478 }
479
480 /**
481 * Uncapitalize a <code>String</code>, changing the first letter to
482 * lower case as per {@link Character#toLowerCase(char)}.
483 * No other letters are changed.
484 * @param str the String to uncapitalize, may be <code>null</code>
485 * @return the uncapitalized String, <code>null</code> if null
486 */
487 public static String uncapitalize(String str) {
488 return changeFirstCharacterCase(str, false);
489 }
490
491 private static String changeFirstCharacterCase(String str, boolean capitalize) {
492 if (str == null || str.length() == 0) {
493 return str;
494 }
495 StringBuffer buf = new StringBuffer(str.length());
496 if (capitalize) {
497 buf.append(Character.toUpperCase(str.charAt(0)));
498 }
499 else {
500 buf.append(Character.toLowerCase(str.charAt(0)));
501 }
502 buf.append(str.substring(1));
503 return buf.toString();
504 }
505
506 /**
507 * Extract the filename from the given path,
508 * e.g. "mypath/myfile.txt" to "myfile.txt".
509 * @param path the file path (may be <code>null</code>)
510 * @return the extracted filename, or <code>null</code> if none
511 */
512 public static String getFilename(String path) {
513 if (path == null) {
514 return null;
515 }
516 int separatorIndex = path.lastIndexOf(FOLDER_SEPARATOR);
517 return (separatorIndex != -1 ? path.substring(separatorIndex + 1) : path);
518 }
519
520 /**
521 * Extract the filename extension from the given path,
522 * e.g. "mypath/myfile.txt" to "txt".
523 * @param path the file path (may be <code>null</code>)
524 * @return the extracted filename extension, or <code>null</code> if none
525 */
526 public static String getFilenameExtension(String path) {
527 if (path == null) {
528 return null;
529 }
530 int sepIndex = path.lastIndexOf(EXTENSION_SEPARATOR);
531 return (sepIndex != -1 ? path.substring(sepIndex + 1) : null);
532 }
533
534 /**
535 * Strip the filename extension from the given path,
536 * e.g. "mypath/myfile.txt" to "mypath/myfile".
537 * @param path the file path (may be <code>null</code>)
538 * @return the path with stripped filename extension,
539 * or <code>null</code> if none
540 */
541 public static String stripFilenameExtension(String path) {
542 if (path == null) {
543 return null;
544 }
545 int sepIndex = path.lastIndexOf(EXTENSION_SEPARATOR);
546 return (sepIndex != -1 ? path.substring(0, sepIndex) : path);
547 }
548
549 /**
550 * Apply the given relative path to the given path,
551 * assuming standard Java folder separation (i.e. "/" separators);
552 * @param path the path to start from (usually a full file path)
553 * @param relativePath the relative path to apply
554 * (relative to the full file path above)
555 * @return the full file path that results from applying the relative path
556 */
557 public static String applyRelativePath(String path, String relativePath) {
558 int separatorIndex = path.lastIndexOf(FOLDER_SEPARATOR);
559 if (separatorIndex != -1) {
560 String newPath = path.substring(0, separatorIndex);
561 if (!relativePath.startsWith(FOLDER_SEPARATOR)) {
562 newPath += FOLDER_SEPARATOR;
563 }
564 return newPath + relativePath;
565 }
566 else {
567 return relativePath;
568 }
569 }
570
571 /**
572 * Normalize the path by suppressing sequences like "path/.." and
573 * inner simple dots.
574 * <p>The result is convenient for path comparison. For other uses,
575 * notice that Windows separators ("\") are replaced by simple slashes.
576 * @param path the original path
577 * @return the normalized path
578 */
579 public static String cleanPath(String path) {
580 if (path == null) {
581 return null;
582 }
583 String pathToUse = replace(path, WINDOWS_FOLDER_SEPARATOR, FOLDER_SEPARATOR);
584
585 // Strip prefix from path to analyze, to not treat it as part of the
586 // first path element. This is necessary to correctly parse paths like
587 // "file:core/../core/io/Resource.class", where the ".." should just
588 // strip the first "core" directory while keeping the "file:" prefix.
589 int prefixIndex = pathToUse.indexOf(":");
590 String prefix = "";
591 if (prefixIndex != -1) {
592 prefix = pathToUse.substring(0, prefixIndex + 1);
593 pathToUse = pathToUse.substring(prefixIndex + 1);
594 }
595 if (pathToUse.startsWith(FOLDER_SEPARATOR)) {
596 prefix = prefix + FOLDER_SEPARATOR;
597 pathToUse = pathToUse.substring(1);
598 }
599
600 String[] pathArray = delimitedListToStringArray(pathToUse, FOLDER_SEPARATOR);
601 List pathElements = new LinkedList();
602 int tops = 0;
603
604 for (int i = pathArray.length - 1; i >= 0; i--) {
605 String element = pathArray[i];
606 if (CURRENT_PATH.equals(element)) {
607 // Points to current directory - drop it.
608 }
609 else if (TOP_PATH.equals(element)) {
610 // Registering top path found.
611 tops++;
612 }
613 else {
614 if (tops > 0) {
615 // Merging path element with element corresponding to top path.
616 tops--;
617 }
618 else {
619 // Normal path element found.
620 pathElements.add(0, element);
621 }
622 }
623 }
624
625 // Remaining top paths need to be retained.
626 for (int i = 0; i < tops; i++) {
627 pathElements.add(0, TOP_PATH);
628 }
629
630 return prefix + collectionToDelimitedString(pathElements, FOLDER_SEPARATOR);
631 }
632
633 /**
634 * Compare two paths after normalization of them.
635 * @param path1 first path for comparison
636 * @param path2 second path for comparison
637 * @return whether the two paths are equivalent after normalization
638 */
639 public static boolean pathEquals(String path1, String path2) {
640 return cleanPath(path1).equals(cleanPath(path2));
641 }
642
643 /**
644 * Parse the given <code>localeString</code> into a {@link Locale}.
645 * <p>This is the inverse operation of {@link Locale#toString Locale's toString}.
646 * @param localeString the locale string, following <code>Locale's</code>
647 * <code>toString()</code> format ("en", "en_UK", etc);
648 * also accepts spaces as separators, as an alternative to underscores
649 * @return a corresponding <code>Locale</code> instance
650 */
651 public static Locale parseLocaleString(String localeString) {
652 String[] parts = tokenizeToStringArray(localeString, "_ ", false, false);
653 String language = (parts.length > 0 ? parts[0] : "");
654 String country = (parts.length > 1 ? parts[1] : "");
655 String variant = "";
656 if (parts.length >= 2) {
657 // There is definitely a variant, and it is everything after the country
658 // code sans the separator between the country code and the variant.
659 int endIndexOfCountryCode = localeString.indexOf(country) + country.length();
660 // Strip off any leading '_' and whitespace, what's left is the variant.
661 variant = trimLeadingWhitespace(localeString.substring(endIndexOfCountryCode));
662 if (variant.startsWith("_")) {
663 variant = trimLeadingCharacter(variant, '_');
664 }
665 }
666 return (language.length() > 0 ? new Locale(language, country, variant) : null);
667 }
668
669 /**
670 * Determine the RFC 3066 compliant language tag,
671 * as used for the HTTP "Accept-Language" header.
672 * @param locale the Locale to transform to a language tag
673 * @return the RFC 3066 compliant language tag as String
674 */
675 public static String toLanguageTag(Locale locale) {
676 return locale.getLanguage() + (hasText(locale.getCountry()) ? "-" + locale.getCountry() : "");
677 }
678
679
680 //---------------------------------------------------------------------
681 // Convenience methods for working with String arrays
682 //---------------------------------------------------------------------
683
684 /**
685 * Append the given String to the given String array, returning a new array
686 * consisting of the input array contents plus the given String.
687 * @param array the array to append to (can be <code>null</code>)
688 * @param str the String to append
689 * @return the new array (never <code>null</code>)
690 */
691 public static String[] addStringToArray(String[] array, String str) {
692 if (ObjectUtils.isEmpty(array)) {
693 return new String[] {str};
694 }
695 String[] newArr = new String[array.length + 1];
696 System.arraycopy(array, 0, newArr, 0, array.length);
697 newArr[array.length] = str;
698 return newArr;
699 }
700
701 /**
702 * Concatenate the given String arrays into one,
703 * with overlapping array elements included twice.
704 * <p>The order of elements in the original arrays is preserved.
705 * @param array1 the first array (can be <code>null</code>)
706 * @param array2 the second array (can be <code>null</code>)
707 * @return the new array (<code>null</code> if both given arrays were <code>null</code>)
708 */
709 public static String[] concatenateStringArrays(String[] array1, String[] array2) {
710 if (ObjectUtils.isEmpty(array1)) {
711 return array2;
712 }
713 if (ObjectUtils.isEmpty(array2)) {
714 return array1;
715 }
716 String[] newArr = new String[array1.length + array2.length];
717 System.arraycopy(array1, 0, newArr, 0, array1.length);
718 System.arraycopy(array2, 0, newArr, array1.length, array2.length);
719 return newArr;
720 }
721
722 /**
723 * Merge the given String arrays into one, with overlapping
724 * array elements only included once.
725 * <p>The order of elements in the original arrays is preserved
726 * (with the exception of overlapping elements, which are only
727 * included on their first occurence).
728 * @param array1 the first array (can be <code>null</code>)
729 * @param array2 the second array (can be <code>null</code>)
730 * @return the new array (<code>null</code> if both given arrays were <code>null</code>)
731 */
732 public static String[] mergeStringArrays(String[] array1, String[] array2) {
733 if (ObjectUtils.isEmpty(array1)) {
734 return array2;
735 }
736 if (ObjectUtils.isEmpty(array2)) {
737 return array1;
738 }
739 List result = new ArrayList();
740 result.addAll(Arrays.asList(array1));
741 for (int i = 0; i < array2.length; i++) {
742 String str = array2[i];
743 if (!result.contains(str)) {
744 result.add(str);
745 }
746 }
747 return toStringArray(result);
748 }
749
750 /**
751 * Turn given source String array into sorted array.
752 * @param array the source array
753 * @return the sorted array (never <code>null</code>)
754 */
755 public static String[] sortStringArray(String[] array) {
756 if (ObjectUtils.isEmpty(array)) {
757 return new String[0];
758 }
759 Arrays.sort(array);
760 return array;
761 }
762
763 /**
764 * Copy the given Collection into a String array.
765 * The Collection must contain String elements only.
766 * @param collection the Collection to copy
767 * @return the String array (<code>null</code> if the passed-in
768 * Collection was <code>null</code>)
769 */
770 public static String[] toStringArray(Collection collection) {
771 if (collection == null) {
772 return null;
773 }
774 return (String[]) collection.toArray(new String[collection.size()]);
775 }
776
777 /**
778 * Copy the given Enumeration into a String array.
779 * The Enumeration must contain String elements only.
780 * @param enumeration the Enumeration to copy
781 * @return the String array (<code>null</code> if the passed-in
782 * Enumeration was <code>null</code>)
783 */
784 public static String[] toStringArray(Enumeration enumeration) {
785 if (enumeration == null) {
786 return null;
787 }
788 List list = Collections.list(enumeration);
789 return (String[]) list.toArray(new String[list.size()]);
790 }
791
792 /**
793 * Trim the elements of the given String array,
794 * calling <code>String.trim()</code> on each of them.
795 * @param array the original String array
796 * @return the resulting array (of the same size) with trimmed elements
797 */
798 public static String[] trimArrayElements(String[] array) {
799 if (ObjectUtils.isEmpty(array)) {
800 return new String[0];
801 }
802 String[] result = new String[array.length];
803 for (int i = 0; i < array.length; i++) {
804 String element = array[i];
805 result[i] = (element != null ? element.trim() : null);
806 }
807 return result;
808 }
809
810 /**
811 * Remove duplicate Strings from the given array.
812 * Also sorts the array, as it uses a TreeSet.
813 * @param array the String array
814 * @return an array without duplicates, in natural sort order
815 */
816 public static String[] removeDuplicateStrings(String[] array) {
817 if (ObjectUtils.isEmpty(array)) {
818 return array;
819 }
820 Set set = new TreeSet();
821 for (int i = 0; i < array.length; i++) {
822 set.add(array[i]);
823 }
824 return toStringArray(set);
825 }
826
827 /**
828 * Split a String at the first occurrence of the delimiter.
829 * Does not include the delimiter in the result.
830 * @param toSplit the string to split
831 * @param delimiter to split the string up with
832 * @return a two element array with index 0 being before the delimiter, and
833 * index 1 being after the delimiter (neither element includes the delimiter);
834 * or <code>null</code> if the delimiter wasn't found in the given input String
835 */
836 public static String[] split(String toSplit, String delimiter) {
837 if (!hasLength(toSplit) || !hasLength(delimiter)) {
838 return null;
839 }
840 int offset = toSplit.indexOf(delimiter);
841 if (offset < 0) {
842 return null;
843 }
844 String beforeDelimiter = toSplit.substring(0, offset);
845 String afterDelimiter = toSplit.substring(offset + delimiter.length());
846 return new String[] {beforeDelimiter, afterDelimiter};
847 }
848
849 /**
850 * Take an array Strings and split each element based on the given delimiter.
851 * A <code>Properties</code> instance is then generated, with the left of the
852 * delimiter providing the key, and the right of the delimiter providing the value.
853 * <p>Will trim both the key and value before adding them to the
854 * <code>Properties</code> instance.
855 * @param array the array to process
856 * @param delimiter to split each element using (typically the equals symbol)
857 * @return a <code>Properties</code> instance representing the array contents,
858 * or <code>null</code> if the array to process was null or empty
859 */
860 public static Properties splitArrayElementsIntoProperties(String[] array, String delimiter) {
861 return splitArrayElementsIntoProperties(array, delimiter, null);
862 }
863
864 /**
865 * Take an array Strings and split each element based on the given delimiter.
866 * A <code>Properties</code> instance is then generated, with the left of the
867 * delimiter providing the key, and the right of the delimiter providing the value.
868 * <p>Will trim both the key and value before adding them to the
869 * <code>Properties</code> instance.
870 * @param array the array to process
871 * @param delimiter to split each element using (typically the equals symbol)
872 * @param charsToDelete one or more characters to remove from each element
873 * prior to attempting the split operation (typically the quotation mark
874 * symbol), or <code>null</code> if no removal should occur
875 * @return a <code>Properties</code> instance representing the array contents,
876 * or <code>null</code> if the array to process was <code>null</code> or empty
877 */
878 public static Properties splitArrayElementsIntoProperties(
879 String[] array, String delimiter, String charsToDelete) {
880
881 if (ObjectUtils.isEmpty(array)) {
882 return null;
883 }
884 Properties result = new Properties();
885 for (int i = 0; i < array.length; i++) {
886 String element = array[i];
887 if (charsToDelete != null) {
888 element = deleteAny(array[i], charsToDelete);
889 }
890 String[] splittedElement = split(element, delimiter);
891 if (splittedElement == null) {
892 continue;
893 }
894 result.setProperty(splittedElement[0].trim(), splittedElement[1].trim());
895 }
896 return result;
897 }
898
899 /**
900 * Tokenize the given String into a String array via a StringTokenizer.
901 * Trims tokens and omits empty tokens.
902 * <p>The given delimiters string is supposed to consist of any number of
903 * delimiter characters. Each of those characters can be used to separate
904 * tokens. A delimiter is always a single character; for multi-character
905 * delimiters, consider using <code>delimitedListToStringArray</code>
906 * @param str the String to tokenize
907 * @param delimiters the delimiter characters, assembled as String
908 * (each of those characters is individually considered as delimiter).
909 * @return an array of the tokens
910 * @see java.util.StringTokenizer
911 * @see java.lang.String#trim()
912 * @see #delimitedListToStringArray
913 */
914 public static String[] tokenizeToStringArray(String str, String delimiters) {
915 return tokenizeToStringArray(str, delimiters, true, true);
916 }
917
918 /**
919 * Tokenize the given String into a String array via a StringTokenizer.
920 * <p>The given delimiters string is supposed to consist of any number of
921 * delimiter characters. Each of those characters can be used to separate
922 * tokens. A delimiter is always a single character; for multi-character
923 * delimiters, consider using <code>delimitedListToStringArray</code>
924 * @param str the String to tokenize
925 * @param delimiters the delimiter characters, assembled as String
926 * (each of those characters is individually considered as delimiter)
927 * @param trimTokens trim the tokens via String's <code>trim</code>
928 * @param ignoreEmptyTokens omit empty tokens from the result array
929 * (only applies to tokens that are empty after trimming; StringTokenizer
930 * will not consider subsequent delimiters as token in the first place).
931 * @return an array of the tokens (<code>null</code> if the input String
932 * was <code>null</code>)
933 * @see java.util.StringTokenizer
934 * @see java.lang.String#trim()
935 * @see #delimitedListToStringArray
936 */
937 public static String[] tokenizeToStringArray(
938 String str, String delimiters, boolean trimTokens, boolean ignoreEmptyTokens) {
939
940 if (str == null) {
941 return null;
942 }
943 StringTokenizer st = new StringTokenizer(str, delimiters);
944 List tokens = new ArrayList();
945 while (st.hasMoreTokens()) {
946 String token = st.nextToken();
947 if (trimTokens) {
948 token = token.trim();
949 }
950 if (!ignoreEmptyTokens || token.length() > 0) {
951 tokens.add(token);
952 }
953 }
954 return toStringArray(tokens);
955 }
956
957 /**
958 * Take a String which is a delimited list and convert it to a String array.
959 * <p>A single delimiter can consists of more than one character: It will still
960 * be considered as single delimiter string, rather than as bunch of potential
961 * delimiter characters - in contrast to <code>tokenizeToStringArray</code>.
962 * @param str the input String
963 * @param delimiter the delimiter between elements (this is a single delimiter,
964 * rather than a bunch individual delimiter characters)
965 * @return an array of the tokens in the list
966 * @see #tokenizeToStringArray
967 */
968 public static String[] delimitedListToStringArray(String str, String delimiter) {
969 return delimitedListToStringArray(str, delimiter, null);
970 }
971
972 /**
973 * Take a String which is a delimited list and convert it to a String array.
974 * <p>A single delimiter can consists of more than one character: It will still
975 * be considered as single delimiter string, rather than as bunch of potential
976 * delimiter characters - in contrast to <code>tokenizeToStringArray</code>.
977 * @param str the input String
978 * @param delimiter the delimiter between elements (this is a single delimiter,
979 * rather than a bunch individual delimiter characters)
980 * @param charsToDelete a set of characters to delete. Useful for deleting unwanted
981 * line breaks: e.g. "\r\n\f" will delete all new lines and line feeds in a String.
982 * @return an array of the tokens in the list
983 * @see #tokenizeToStringArray
984 */
985 public static String[] delimitedListToStringArray(String str, String delimiter, String charsToDelete) {
986 if (str == null) {
987 return new String[0];
988 }
989 if (delimiter == null) {
990 return new String[] {str};
991 }
992 List result = new ArrayList();
993 if ("".equals(delimiter)) {
994 for (int i = 0; i < str.length(); i++) {
995 result.add(deleteAny(str.substring(i, i + 1), charsToDelete));
996 }
997 }
998 else {
999 int pos = 0;
1000 int delPos = 0;
1001 while ((delPos = str.indexOf(delimiter, pos)) != -1) {
1002 result.add(deleteAny(str.substring(pos, delPos), charsToDelete));
1003 pos = delPos + delimiter.length();
1004 }
1005 if (str.length() > 0 && pos <= str.length()) {
1006 // Add rest of String, but not in case of empty input.
1007 result.add(deleteAny(str.substring(pos), charsToDelete));
1008 }
1009 }
1010 return toStringArray(result);
1011 }
1012
1013 /**
1014 * Convert a CSV list into an array of Strings.
1015 * @param str the input String
1016 * @return an array of Strings, or the empty array in case of empty input
1017 */
1018 public static String[] commaDelimitedListToStringArray(String str) {
1019 return delimitedListToStringArray(str, ",");
1020 }
1021
1022 /**
1023 * Convenience method to convert a CSV string list to a set.
1024 * Note that this will suppress duplicates.
1025 * @param str the input String
1026 * @return a Set of String entries in the list
1027 */
1028 public static Set commaDelimitedListToSet(String str) {
1029 Set set = new TreeSet();
1030 String[] tokens = commaDelimitedListToStringArray(str);
1031 for (int i = 0; i < tokens.length; i++) {
1032 set.add(tokens[i]);
1033 }
1034 return set;
1035 }
1036
1037 /**
1038 * Convenience method to return a Collection as a delimited (e.g. CSV)
1039 * String. E.g. useful for <code>toString()</code> implementations.
1040 * @param coll the Collection to display
1041 * @param delim the delimiter to use (probably a ",")
1042 * @param prefix the String to start each element with
1043 * @param suffix the String to end each element with
1044 * @return the delimited String
1045 */
1046 public static String collectionToDelimitedString(Collection coll, String delim, String prefix, String suffix) {
1047 if (CollectionUtils.isEmpty(coll)) {
1048 return "";
1049 }
1050 StringBuffer sb = new StringBuffer();
1051 Iterator it = coll.iterator();
1052 while (it.hasNext()) {
1053 sb.append(prefix).append(it.next()).append(suffix);
1054 if (it.hasNext()) {
1055 sb.append(delim);
1056 }
1057 }
1058 return sb.toString();
1059 }
1060
1061 /**
1062 * Convenience method to return a Collection as a delimited (e.g. CSV)
1063 * String. E.g. useful for <code>toString()</code> implementations.
1064 * @param coll the Collection to display
1065 * @param delim the delimiter to use (probably a ",")
1066 * @return the delimited String
1067 */
1068 public static String collectionToDelimitedString(Collection coll, String delim) {
1069 return collectionToDelimitedString(coll, delim, "", "");
1070 }
1071
1072 /**
1073 * Convenience method to return a Collection as a CSV String.
1074 * E.g. useful for <code>toString()</code> implementations.
1075 * @param coll the Collection to display
1076 * @return the delimited String
1077 */
1078 public static String collectionToCommaDelimitedString(Collection coll) {
1079 return collectionToDelimitedString(coll, ",");
1080 }
1081
1082 /**
1083 * Convenience method to return a String array as a delimited (e.g. CSV)
1084 * String. E.g. useful for <code>toString()</code> implementations.
1085 * @param arr the array to display
1086 * @param delim the delimiter to use (probably a ",")
1087 * @return the delimited String
1088 */
1089 public static String arrayToDelimitedString(Object[] arr, String delim) {
1090 if (ObjectUtils.isEmpty(arr)) {
1091 return "";
1092 }
1093 StringBuffer sb = new StringBuffer();
1094 for (int i = 0; i < arr.length; i++) {
1095 if (i > 0) {
1096 sb.append(delim);
1097 }
1098 sb.append(arr[i]);
1099 }
1100 return sb.toString();
1101 }
1102
1103 /**
1104 * Convenience method to return a String array as a CSV String.
1105 * E.g. useful for <code>toString()</code> implementations.
1106 * @param arr the array to display
1107 * @return the delimited String
1108 */
1109 public static String arrayToCommaDelimitedString(Object[] arr) {
1110 return arrayToDelimitedString(arr, ",");
1111 }
1112
1113 }