1 /**
2 * Copyright 2005-2011 The Kuali Foundation
3 *
4 * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
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 package org.kuali.rice.core.api.cache;
17
18
19
20 import java.util.ArrayList;
21 import java.util.Collection;
22 import java.util.Collections;
23 import java.util.List;
24 import java.util.Map;
25 import java.util.SortedMap;
26 import java.util.TreeMap;
27
28 /**
29 * This is a utility class that generates cache keys for compound objects.
30 */
31 public final class CacheKeyUtils {
32
33 private CacheKeyUtils() {
34 throw new UnsupportedOperationException("do not call.");
35 }
36
37 /**
38 * Create a String key value out of a Map. The Map should really just contain
39 * simple types.
40 * @param map the map. if null will return ""
41 * @param <K> the map key type
42 * @return the map as a string value
43 */
44 public static <K extends Comparable<K>> String key(Map<K, ?> map) {
45 if (map == null) {
46 return "";
47 }
48
49 final SortedMap<K, ?> sorted = new TreeMap<K, Object>(map);
50 final StringBuilder b = new StringBuilder("[");
51 for (Map.Entry<K, ?> entry : sorted.entrySet()) {
52 if (entry != null && entry.getKey() != null && entry.getValue() != null) {
53 b.append(entry.getKey());
54 b.append(":");
55 b.append(entry.getValue());
56 b.append(",");
57 }
58 }
59 b.append("]");
60 return b.toString();
61 }
62
63 /**
64 * Create a String key value out of a Collection. The Collection should really just contain
65 * simple types.
66 * @param col the collection. if null will return ""
67 * @param <K> the col type
68 * @return the collection as a string value
69 */
70 public static <K extends Comparable<K>> String key(Collection<K> col) {
71 if (col == null) {
72 return "";
73 }
74
75 final List<K> sorted = new ArrayList<K>(col);
76 Collections.sort(sorted);
77 final StringBuilder b = new StringBuilder("[");
78 for (K entry : sorted) {
79 if (entry != null) {
80 b.append(entry);
81 b.append(",");
82 }
83 }
84 b.append("]");
85 return b.toString();
86 }
87
88 }