1 /*
2 * #%L
3 * settings4j
4 * ===============================================================
5 * Copyright (C) 2008 - 2015 Brabenetz Harald, Austria
6 * ===============================================================
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 * #L%
19 */
20 package org.settings4j.objectresolver;
21
22 import org.settings4j.ContentResolver;
23 import org.settings4j.ObjectResolver;
24
25 /**
26 * The UnionObjectResolver can be an container for many other {@link ObjectResolver} which will be processed in sequence.
27 * <p>
28 * the first result of a ObjectResolver which are a not-null value will be used as result.
29 * </p>
30 *
31 * @author Harald.Brabenetz
32 */
33 public class UnionObjectResolver implements ObjectResolver {
34
35 private ObjectResolver[] objectResolvers = new ObjectResolver[0];
36
37 @Override
38 public void addObjectResolver(final ObjectResolver objectResolver) {
39
40 final ObjectResolver[] objectResolversNew = new ObjectResolver[this.objectResolvers.length + 1];
41 for (int i = 0; i < this.objectResolvers.length; i++) {
42 objectResolversNew[i] = this.objectResolvers[i];
43 }
44 objectResolversNew[this.objectResolvers.length] = objectResolver;
45
46 this.objectResolvers = objectResolversNew;
47 }
48
49 @Override
50 public Object getObject(final String key, final ContentResolver contentResolver) {
51
52 Object result = null;
53 for (int i = 0; i < this.objectResolvers.length; i++) {
54 result = this.objectResolvers[i].getObject(key, contentResolver);
55 if (result != null) {
56 return result;
57 }
58 }
59 return result;
60 }
61
62 }