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;
21
22
23 /**
24 * The ObjectResolver is a Helper to resolve byte[] Content to a Java Object.
25 * <p>
26 * Example Configuration in settings4j.xml:
27 * </p>
28 *
29 * <pre style="border-width:1px;border-style:solid;">
30 * <connector name="<span style="color:green;">ClasspathConnector</span>"
31 * class="org.settings4j.connector.ClasspathConnector">
32 * <objectResolver-ref ref="<span style="color:red;">JavaXMLBeansObjectResolver</span>" />
33 * </connector>
34 * <objectResolver name="<span style="color:red;">JavaXMLBeansObjectResolver</span>"
35 * class="org.settings4j.objectresolver.JavaXMLBeansObjectResolver" />
36 * </pre>
37 * <p>
38 * You can now store a XMLEncoded (Serialized) Java-Objects into your Classpath.<br>
39 * see {@link org.settings4j.objectresolver.JavaXMLBeansObjectResolver} for more details.<br>
40 * Or see {@link org.settings4j.objectresolver.SpringConfigObjectResolver} for more details on a Spring Configuration File to generate an Object. Requires
41 * Springframework (tested with 2.5.6)
42 * </p>
43 *
44 * @author Harald.Brabenetz
45 */
46 public interface ObjectResolver {
47
48 /**
49 * Reads the byte[] content from the ContentResolver and creates an Object.
50 *
51 * The normal usecase of an implementation of this ObjectResolver Interface:<br>
52 *
53 * <ol>
54 * <li>Read the Propertyfile from {@link ContentResolver}.getContent(key + ".properties")</li>
55 * <li>Read the Value of "objectResolverKey" from propertyfile</li>
56 * <li>The "objectResolverKey" defines which ObjectResolver-Implementation should
57 * solve the byte[] content to a Java-Object</li>
58 * <li>Convert the byte[] from {@link ContentResolver#getContent(String key)} to an Object.</li>
59 * <li>Maybe additional values are consumed from the propertyfile</li>
60 * </ol>
61 *
62 *
63 * @param key The Key of the byte[] who should be converted to an Object.
64 * @param contentResolver The contentResolver, from where the content could be read.
65 * @return the Object, or null if this Object-Resolver can not convert the byte[] Content to an Object.
66 */
67 Object getObject(String key, ContentResolver contentResolver);
68
69 /**
70 * Some Implementations of a {@link ObjectResolver} are delegating the functionality to other ObjectResolvers.
71 * <p>
72 * Examples are: {@link org.settings4j.objectresolver.UnionObjectResolver}
73 * </p>
74 *
75 * <pre>
76 * --------------------------------------
77 * <objectResolver name="DefaultObjectResolver" class="org.settings4j.objectresolver.UnionObjectResolver">
78 * <objectResolver-ref ref="JavaXMLBeansObjectResolver" />
79 * <objectResolver-ref ref="SpringConfigObjectResolver" />
80 * </objectResolver>
81 * --------------------------------------
82 * </pre>
83 *
84 * @param objectResolver
85 * the original objectResolver to delegate.
86 */
87 void addObjectResolver(ObjectResolver objectResolver);
88 }