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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   */
20  package org.apache.mina.statemachine.context;
21  
22  import org.apache.mina.common.IoSession;
23  
24  /**
25   * MINA specific {@link StateContextLookup} which uses an {@link IoSession}
26   * attribute to store the {@link StateContextLookup}.
27   *
28   * @author The Apache MINA Project (dev@mina.apache.org)
29   * @version $Rev: 589477 $, $Date: 2007-10-28 21:19:58 -0600 (Sun, 28 Oct 2007) $
30   */
31  public class IoSessionStateContextLookup extends AbstractStateContextLookup {
32      /**
33       * The name of the {@link IoSession} attribute used to store the
34       * {@link StateContext} object.
35       */
36      public static final String STATE_CONTEXT = 
37          IoSessionStateContextLookup.class.getName() + ".stateContext";
38      
39      /**
40       * Creates a new instance using a {@link DefaultStateContextFactory} to
41       * create {@link StateContext} objects for new {@link IoSession}s.
42       */
43      public IoSessionStateContextLookup() {
44          this(new DefaultStateContextFactory());
45      }
46  
47      /**
48       * Creates a new instance using the specified {@link StateContextFactory} to
49       * create {@link StateContext} objects for new {@link IoSession}s.
50       * 
51       * @param contextFactory the {@link StateContextFactory}.
52       */
53      public IoSessionStateContextLookup(StateContextFactory contextFactory) {
54          super(contextFactory);
55      }
56  
57      protected StateContext lookup(Object eventArg) {
58          IoSession session = (IoSession) eventArg;
59          return (StateContext) session.getAttribute(STATE_CONTEXT);
60      }
61  
62      protected void store(Object eventArg, StateContext context) {
63          IoSession session = (IoSession) eventArg;
64          session.setAttribute(STATE_CONTEXT, context);
65      }
66  
67      protected boolean supports(Class<?> c) {
68          return IoSession.class.isAssignableFrom(c);
69      }
70  }