1 /* ***************************************************************************
2 * Copyright (c) 2008 Brabenetz Harald, Austria.
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
18 package org.settings4j.objectresolver;
19
20 import org.settings4j.ContentResolver;
21 import org.settings4j.Filter;
22 import org.settings4j.ObjectResolver;
23
24 /**
25 * Wrapper to add a {@link Filter} which is used before the given {@link ObjectResolver} is called.
26 *
27 * @author Harald.Brabenetz
28 */
29 public class FilteredObjectResolverWrapper implements ObjectResolver {
30
31 private final ObjectResolver targetObjectResolver;
32 private final Filter filter;
33
34 /**
35 *
36 * @param targetObjectResolver The ObjectResolver where the settings should be read if the Filter allows it.
37 * @param filter the {@link Filter} which defines if an key should be read from the given ObjectResolver.
38 */
39 public FilteredObjectResolverWrapper(final ObjectResolver targetObjectResolver, final Filter filter) {
40 super();
41 if (targetObjectResolver == null) {
42 throw new IllegalArgumentException("FilteredConnectorWrapper needs a ObjectResolver Object");
43 }
44 if (filter == null) {
45 throw new IllegalArgumentException("FilteredConnectorWrapper needs a Filter Object");
46 }
47 this.targetObjectResolver = targetObjectResolver;
48 this.filter = filter;
49 }
50
51 /** {@inheritDoc} */
52 public void addObjectResolver(final ObjectResolver objectResolver) {
53 this.targetObjectResolver.addObjectResolver(objectResolver);
54 }
55
56 /** {@inheritDoc} */
57 public Object getObject(final String key, final ContentResolver contentResolver) {
58 if (!this.filter.isValid(key)) {
59 return null;
60 }
61 return this.targetObjectResolver.getObject(key, contentResolver);
62 }
63 }