1
22
23 package com.liferay.portal.kernel.util;
24
25 import com.liferay.portal.kernel.bean.BeanPropertiesUtil;
26
27 import java.io.BufferedReader;
28 import java.io.File;
29 import java.io.FileReader;
30 import java.io.IOException;
31
32 import java.util.ArrayList;
33 import java.util.Collection;
34 import java.util.Collections;
35 import java.util.Comparator;
36 import java.util.Enumeration;
37 import java.util.Iterator;
38 import java.util.List;
39 import java.util.Set;
40 import java.util.TreeSet;
41
42
48 public class ListUtil {
49
50 public static List copy(List master) {
51 if (master == null) {
52 return null;
53 }
54
55 List copy = new ArrayList(master.size());
56
57 copy(master, copy);
58
59 return copy;
60 }
61
62 public static void copy(List master, List copy) {
63 if ((master == null) || (copy == null)) {
64 return;
65 }
66
67 copy.clear();
68
69 Iterator itr = master.iterator();
70
71 while (itr.hasNext()) {
72 Object obj = itr.next();
73
74 copy.add(obj);
75 }
76 }
77
78 public static void distinct(List list) {
79 distinct(list, null);
80 }
81
82 public static void distinct(List list, Comparator comparator) {
83 if ((list == null) || (list.size() == 0)) {
84 return;
85 }
86
87 Set set = null;
88
89 if (comparator == null) {
90 set = new TreeSet();
91 }
92 else {
93 set = new TreeSet(comparator);
94 }
95
96 Iterator itr = list.iterator();
97
98 while (itr.hasNext()) {
99 Object obj = itr.next();
100
101 if (set.contains(obj)) {
102 itr.remove();
103 }
104 else {
105 set.add(obj);
106 }
107 }
108 }
109
110 public static List fromArray(Object[] array) {
111 if ((array == null) || (array.length == 0)) {
112 return new ArrayList();
113 }
114
115 List list = new ArrayList(array.length);
116
117 for (int i = 0; i < array.length; i++) {
118 list.add(array[i]);
119 }
120
121 return list;
122 }
123
124 public static List fromCollection(Collection c) {
125 if ((c != null) && (c instanceof List)) {
126 return (List)c;
127 }
128
129 if ((c == null) || (c.size() == 0)) {
130 return new ArrayList();
131 }
132
133 List list = new ArrayList(c.size());
134
135 Iterator itr = c.iterator();
136
137 while (itr.hasNext()) {
138 list.add(itr.next());
139 }
140
141 return list;
142 }
143
144 public static List fromEnumeration(Enumeration enu) {
145 List list = new ArrayList();
146
147 while (enu.hasMoreElements()) {
148 Object obj = enu.nextElement();
149
150 list.add(obj);
151 }
152
153 return list;
154 }
155
156 public static List fromFile(String fileName) throws IOException {
157 return fromFile(new File(fileName));
158 }
159
160 public static List fromFile(File file) throws IOException {
161 List list = new ArrayList();
162
163 BufferedReader br = new BufferedReader(new FileReader(file));
164
165 String s = StringPool.BLANK;
166
167 while ((s = br.readLine()) != null) {
168 list.add(s);
169 }
170
171 br.close();
172
173 return list;
174 }
175
176 public static List fromString(String s) {
177 return fromArray(StringUtil.split(s, StringPool.NEW_LINE));
178 }
179
180 public static List subList(List list, int start, int end) {
181 List newList = new ArrayList();
182
183 int normalizedSize = list.size() - 1;
184
185 if ((start < 0) || (start > normalizedSize) || (end < 0) ||
186 (start > end)) {
187
188 return newList;
189 }
190
191 for (int i = start; i < end && i <= normalizedSize; i++) {
192 newList.add(list.get(i));
193 }
194
195 return newList;
196 }
197
198 public static String toString(List list, String param) {
199 return toString(list, param, StringPool.COMMA);
200 }
201
202 public static String toString(List list, String param, String delimiter) {
203 StringBuilder sb = new StringBuilder();
204
205 for (int i = 0; i < list.size(); i++) {
206 Object bean = list.get(i);
207
208 Object value = BeanPropertiesUtil.getObject(bean, param);
209
210 if (value == null) {
211 value = StringPool.BLANK;
212 }
213
214 sb.append(value.toString());
215
216 if ((i + 1) != list.size()) {
217 sb.append(delimiter);
218 }
219 }
220
221 return sb.toString();
222 }
223
224 public static List<Boolean> toList(Boolean[] list) {
225 if ((list == null) || (list.length == 0)) {
226 return Collections.EMPTY_LIST;
227 }
228
229 List<Boolean> newList = new ArrayList<Boolean>(list.length);
230
231 for (Boolean value : list) {
232 newList.add(value);
233 }
234
235 return newList;
236 }
237
238 public static List<Double> toList(Double[] list) {
239 if ((list == null) || (list.length == 0)) {
240 return Collections.EMPTY_LIST;
241 }
242
243 List<Double> newList = new ArrayList<Double>(list.length);
244
245 for (Double value : list) {
246 newList.add(value);
247 }
248
249 return newList;
250 }
251
252 public static List<Float> toList(Float[] list) {
253 if ((list == null) || (list.length == 0)) {
254 return Collections.EMPTY_LIST;
255 }
256
257 List<Float> newList = new ArrayList<Float>(list.length);
258
259 for (Float value : list) {
260 newList.add(value);
261 }
262
263 return newList;
264 }
265
266 public static List<Integer> toList(Integer[] list) {
267 if ((list == null) || (list.length == 0)) {
268 return Collections.EMPTY_LIST;
269 }
270
271 List<Integer> newList = new ArrayList<Integer>(list.length);
272
273 for (Integer value : list) {
274 newList.add(value);
275 }
276
277 return newList;
278 }
279
280 public static List<Long> toList(Long[] list) {
281 if ((list == null) || (list.length == 0)) {
282 return Collections.EMPTY_LIST;
283 }
284
285 List<Long> newList = new ArrayList<Long>(list.length);
286
287 for (Long value : list) {
288 newList.add(value);
289 }
290
291 return newList;
292 }
293
294 public static List<Short> toList(Short[] list) {
295 if ((list == null) || (list.length == 0)) {
296 return Collections.EMPTY_LIST;
297 }
298
299 List<Short> newList = new ArrayList<Short>(list.length);
300
301 for (Short value : list) {
302 newList.add(value);
303 }
304
305 return newList;
306 }
307
308 public static List<String> toList(String[] list) {
309 if ((list == null) || (list.length == 0)) {
310 return Collections.EMPTY_LIST;
311 }
312
313 List<String> newList = new ArrayList<String>(list.length);
314
315 for (String value : list) {
316 newList.add(value);
317 }
318
319 return newList;
320 }
321
322 }