001
014
015 package com.liferay.portal.kernel.util;
016
017 import com.liferay.portal.kernel.bean.BeanPropertiesUtil;
018 import com.liferay.portal.kernel.io.unsync.UnsyncBufferedReader;
019
020 import java.io.File;
021 import java.io.FileReader;
022 import java.io.IOException;
023
024 import java.util.ArrayList;
025 import java.util.Arrays;
026 import java.util.Collection;
027 import java.util.Collections;
028 import java.util.Comparator;
029 import java.util.Enumeration;
030 import java.util.HashSet;
031 import java.util.Iterator;
032 import java.util.List;
033 import java.util.Map;
034 import java.util.Set;
035
036
040 public class ListUtil {
041
042 public static <E> List<E> copy(List<E> master) {
043 if (master == null) {
044 return null;
045 }
046
047 return new ArrayList<E>(master);
048 }
049
050 public static <E> void copy(List<E> master, List<? super E> copy) {
051 if ((master == null) || (copy == null)) {
052 return;
053 }
054
055 copy.clear();
056
057 copy.addAll(master);
058 }
059
060 public static void distinct(List<?> list) {
061 distinct(list, null);
062 }
063
064 public static <E> void distinct(List<E> list, Comparator<E> comparator) {
065 if ((list == null) || list.isEmpty()) {
066 return;
067 }
068
069 Set<E> set = new HashSet<E>();
070
071 Iterator<E> itr = list.iterator();
072
073 while (itr.hasNext()) {
074 E obj = itr.next();
075
076 if (set.contains(obj)) {
077 itr.remove();
078 }
079 else {
080 set.add(obj);
081 }
082 }
083
084 if (comparator != null) {
085 Collections.sort(list, comparator);
086 }
087 }
088
089 public static <E> List<E> fromArray(E[] array) {
090 if ((array == null) || (array.length == 0)) {
091 return new ArrayList<E>();
092 }
093
094 return new ArrayList<E>(Arrays.asList(array));
095 }
096
097 @SuppressWarnings("rawtypes")
098 public static <E> List<E> fromCollection(Collection<E> c) {
099 if ((c != null) && (List.class.isAssignableFrom(c.getClass()))) {
100 return (List)c;
101 }
102
103 if ((c == null) || c.isEmpty()) {
104 return new ArrayList<E>();
105 }
106
107 List<E> list = new ArrayList<E>(c.size());
108
109 list.addAll(c);
110
111 return list;
112 }
113
114 public static <E> List<E> fromEnumeration(Enumeration<E> enu) {
115 List<E> list = new ArrayList<E>();
116
117 while (enu.hasMoreElements()) {
118 E obj = enu.nextElement();
119
120 list.add(obj);
121 }
122
123 return list;
124 }
125
126 public static List<String> fromFile(File file) throws IOException {
127 if (!file.exists()) {
128 return new ArrayList<String>();
129 }
130
131 List<String> list = new ArrayList<String>();
132
133 UnsyncBufferedReader unsyncBufferedReader = new UnsyncBufferedReader(
134 new FileReader(file));
135
136 String s = StringPool.BLANK;
137
138 while ((s = unsyncBufferedReader.readLine()) != null) {
139 list.add(s);
140 }
141
142 unsyncBufferedReader.close();
143
144 return list;
145 }
146
147 public static List<String> fromFile(String fileName) throws IOException {
148 return fromFile(new File(fileName));
149 }
150
151 public static <E> List<E> fromMapKeys(Map<E, ?> map) {
152 if ((map == null) || map.isEmpty()) {
153 return new ArrayList<E>();
154 }
155
156 List<E> list = new ArrayList<E>(map.size());
157
158 for (Map.Entry<E, ?> entry : map.entrySet()) {
159 list.add(entry.getKey());
160 }
161
162 return list;
163 }
164
165 public static <E> List<E> fromMapValues(Map<?, E> map) {
166 if ((map == null) || map.isEmpty()) {
167 return new ArrayList<E>();
168 }
169
170 List<E> list = new ArrayList<E>(map.size());
171
172 for (Map.Entry<?, E> entry : map.entrySet()) {
173 list.add(entry.getValue());
174 }
175
176 return list;
177 }
178
179 public static List<String> fromString(String s) {
180 return fromArray(StringUtil.splitLines(s));
181 }
182
183 public static <E> boolean remove(List<E> list, E element) {
184 Iterator<E> itr = list.iterator();
185
186 while (itr.hasNext()) {
187 E curElement = itr.next();
188
189 if ((curElement == element) || curElement.equals(element)) {
190 itr.remove();
191
192 return true;
193 }
194 }
195
196 return false;
197 }
198
199 public static <E> List<E> sort(List<E> list) {
200 return sort(list, null);
201 }
202
203 public static <E> List<E> sort(
204 List<E> list, Comparator<? super E> comparator) {
205
206 if (UnmodifiableList.class.isAssignableFrom(list.getClass())) {
207 list = copy(list);
208 }
209
210 Collections.sort(list, comparator);
211
212 return list;
213 }
214
215 public static <E> List<E> subList(List<E> list, int start, int end) {
216 List<E> newList = new ArrayList<E>();
217
218 int normalizedSize = list.size() - 1;
219
220 if ((start < 0) || (start > normalizedSize) || (end < 0) ||
221 (start > end)) {
222
223 return newList;
224 }
225
226 for (int i = start; (i < end) && (i <= normalizedSize); i++) {
227 newList.add(list.get(i));
228 }
229
230 return newList;
231 }
232
233 public static List<Boolean> toList(boolean[] array) {
234 if ((array == null) || (array.length == 0)) {
235 return new ArrayList<Boolean>();
236 }
237
238 List<Boolean> list = new ArrayList<Boolean>(array.length);
239
240 for (boolean value : array) {
241 list.add(value);
242 }
243
244 return list;
245 }
246
247 public static List<Double> toList(double[] array) {
248 if ((array == null) || (array.length == 0)) {
249 return new ArrayList<Double>();
250 }
251
252 List<Double> list = new ArrayList<Double>(array.length);
253
254 for (double value : array) {
255 list.add(value);
256 }
257
258 return list;
259 }
260
261 public static <E> List<E> toList(E[] array) {
262 if ((array == null) || (array.length == 0)) {
263 return new ArrayList<E>();
264 }
265
266 return new ArrayList<E>(Arrays.asList(array));
267 }
268
269 public static List<Float> toList(float[] array) {
270 if ((array == null) || (array.length == 0)) {
271 return new ArrayList<Float>();
272 }
273
274 List<Float> list = new ArrayList<Float>(array.length);
275
276 for (float value : array) {
277 list.add(value);
278 }
279
280 return list;
281 }
282
283 public static List<Integer> toList(int[] array) {
284 if ((array == null) || (array.length == 0)) {
285 return new ArrayList<Integer>();
286 }
287
288 List<Integer> list = new ArrayList<Integer>(array.length);
289
290 for (int value : array) {
291 list.add(value);
292 }
293
294 return list;
295 }
296
297 public static List<Long> toList(long[] array) {
298 if ((array == null) || (array.length == 0)) {
299 return new ArrayList<Long>();
300 }
301
302 List<Long> list = new ArrayList<Long>(array.length);
303
304 for (long value : array) {
305 list.add(value);
306 }
307
308 return list;
309 }
310
311 public static List<Short> toList(short[] array) {
312 if ((array == null) || (array.length == 0)) {
313 return new ArrayList<Short>();
314 }
315
316 List<Short> list = new ArrayList<Short>(array.length);
317
318 for (short value : array) {
319 list.add(value);
320 }
321
322 return list;
323 }
324
325
328 public static String toString(List<?> list, String param) {
329 return toString(list, param, StringPool.COMMA);
330 }
331
332
335 public static String toString(
336 List<?> list, String param, String delimiter) {
337
338 if ((list == null) || list.isEmpty()) {
339 return StringPool.BLANK;
340 }
341
342 StringBundler sb = new StringBundler(2 * list.size() - 1);
343
344 for (int i = 0; i < list.size(); i++) {
345 Object bean = list.get(i);
346
347 Object value = BeanPropertiesUtil.getObject(bean, param);
348
349 if (value != null) {
350 sb.append(value);
351 }
352
353 if ((i + 1) != list.size()) {
354 sb.append(delimiter);
355 }
356 }
357
358 return sb.toString();
359 }
360
361
364 public static <T, V> String toString(
365 List<T> list, Accessor<T, V> accessor) {
366
367 return toString(list, accessor, StringPool.COMMA);
368 }
369
370
373 public static <T, V> String toString(
374 List<T> list, Accessor<T, V> accessor, String delimiter) {
375
376 if ((list == null) || list.isEmpty()) {
377 return StringPool.BLANK;
378 }
379
380 StringBundler sb = new StringBundler(2 * list.size() - 1);
381
382 for (int i = 0; i < list.size(); i++) {
383 T bean = list.get(i);
384
385 V value = accessor.get(bean);
386
387 if (value != null) {
388 sb.append(value);
389 }
390
391 if ((i + 1) != list.size()) {
392 sb.append(delimiter);
393 }
394 }
395
396 return sb.toString();
397 }
398
399 }