1 /***
2 * Copyright 2003-2010 Terracotta, Inc.
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 net.sf.ehcache.loader;
18
19
20 import net.sf.ehcache.CacheException;
21 import org.slf4j.Logger;
22 import org.slf4j.LoggerFactory;
23
24 import java.util.*;
25
26
27 /***
28 * A cache loader that introduces a configurable delay when used
29 *
30 * @author Ludovic Orban
31 * @version $Id: DelayingLoader.html 13146 2011-08-01 17:12:39Z oletizi $
32 */
33 public class DelayingLoader extends CountingCacheLoader {
34
35 private static final Logger LOG = LoggerFactory.getLogger(DelayingLoader.class.getName());
36
37 private int loadCounter;
38 private int loadAllCounter;
39 private Random random = new Random();
40 private String name = "ExceptionThrowingLoader";
41 private long delayMillis;
42
43 public DelayingLoader(long delayMillis) {
44 this.delayMillis = delayMillis;
45 }
46
47 /***
48 * loads an object. Application writers should implement this
49 * method to customize the loading of cache object. This method is called
50 * by the caching service when the requested object is not in the cache.
51 * <p/>
52 *
53 * @param key the key identifying the object being loaded
54 * @return The object that is to be stored in the cache.
55 */
56 public Object load(Object key) throws CacheException {
57 try {
58 Thread.sleep(delayMillis);
59 } catch (InterruptedException e) {
60 LOG.error("Interrupted");
61 }
62 throw new CacheException("Some exception with key " + key);
63 }
64
65 /***
66 * loads multiple object. Application writers should implement this
67 * method to customize the loading of cache object. This method is called
68 * by the caching service when the requested object is not in the cache.
69 * <p/>
70 *
71 * @param keys a Collection of keys identifying the objects to be loaded
72 * @return A Map of objects that are to be stored in the cache.
73 */
74
75 public Map loadAll(Collection keys) throws CacheException {
76 try {
77 Thread.sleep(delayMillis);
78 } catch (InterruptedException e) {
79 LOG.error("Interrupted");
80 }
81 throw new CacheException("Some exception with keys " + keys);
82 }
83
84
85 /***
86 * Load using both a key and an argument.
87 * <p/>
88 * JCache will use the load(key) method where the argument is null.
89 */
90 public Object load(Object key, Object argument) throws CacheException {
91 try {
92 Thread.sleep(random.nextInt(3) + 1);
93 } catch (InterruptedException e) {
94 LOG.error("Interrupted");
95 }
96 throw new CacheException("Some exception with key " + key);
97 }
98
99 /***
100 * Load using both a key and an argument.
101 * <p/>
102 * JCache will use the loadAll(key) method where the argument is null.
103 */
104 public Map loadAll(Collection keys, Object argument) throws CacheException {
105 throw new CacheException("Some exception with key " + keys.toArray()[0]);
106 }
107
108 }