1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.myfaces.orchestra.conversation;
20
21 import java.util.HashMap;
22 import java.util.Map;
23
24 /**
25 * Maintains a list of aspects the system might attach to a conversation instance.
26 * <p>
27 * Aspects are a way of extending the functionality of a class without modifying it;
28 * it acts something like the "decorator" pattern, but with many different decorator
29 * classes being supported at once.
30 * <p>
31 * In the simplest form, an Aspect can be attached to a Conversation simply as a "marker"
32 * to indicate whether the conversation should be treated in a certain way or not.
33 * <p>
34 * In more sophisticated form, an Aspect can provide an API. Code that wants to
35 * manipulate some "conversation-related" property can query the conversation for the
36 * appropriate Aspect object, then invoke the aspect api to read or write the
37 * Conversation instance via an implementation that is isolated from both the caller
38 * and the Conversation.
39 * <p>
40 * Examples of aspects that can be attached to a conversation are:
41 * <ul>
42 * <li>Timeout handling</li>
43 * <li>Access-scope handling</li>
44 * </ul>
45 */
46 public class ConversationAspects
47 {
48 private Map conversationAspects = new HashMap();
49
50 public void addAspect(ConversationAspect aspect)
51 {
52 conversationAspects.put(aspect.getClass().getName(), aspect);
53 }
54
55 public ConversationAspect getAspect(Class aspectClass)
56 {
57 return (ConversationAspect) conversationAspects.get(aspectClass.getName());
58 }
59 }