1 package org.apache.velocity.runtime.resource;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import java.util.Iterator;
23 import org.apache.velocity.runtime.RuntimeServices;
24
25 /**
26 * Interface that defines the shape of a pluggable resource cache
27 * for the included ResourceManager
28 *
29 * @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a>
30 * @version $Id: ResourceCache.java 463298 2006-10-12 16:10:32Z henning $
31 */
32 public interface ResourceCache
33 {
34 /**
35 * initializes the ResourceCache. Will be
36 * called before any utilization
37 *
38 * @param rs RuntimeServices to use for logging, etc
39 */
40 public void initialize( RuntimeServices rs );
41
42 /**
43 * retrieves a Resource from the
44 * cache
45 *
46 * @param resourceKey key for Resource to be retrieved
47 * @return Resource specified or null if not found
48 */
49 public Resource get( Object resourceKey );
50
51 /**
52 * stores a Resource in the cache
53 *
54 * @param resourceKey key to associate with the Resource
55 * @param resource Resource to be stored
56 * @return existing Resource stored under this key, or null if none
57 */
58 public Resource put( Object resourceKey, Resource resource );
59
60 /**
61 * removes a Resource from the cache
62 *
63 * @param resourceKey resource to be removed
64 * @return stored under key
65 */
66 public Resource remove( Object resourceKey );
67
68 /**
69 * returns an Iterator of Keys in the cache.
70 * @return An Iterator of Keys in the cache.
71 */
72 public Iterator enumerateKeys();
73 }