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 /**
23 * {@link StateContextLookup} implementation which always returns the same
24 * {@link StateContext} instance.
25 *
26 * @author The Apache MINA Project (dev@mina.apache.org)
27 * @version $Rev: 586695 $, $Date: 2007-10-20 12:01:17 +0200 (sam, 20 oct 2007) $
28 */
29 public class SingletonStateContextLookup implements StateContextLookup {
30 private final StateContext context;
31
32 /**
33 * Creates a new instance which always returns the same
34 * {@link DefaultStateContext} instance.
35 */
36 public SingletonStateContextLookup() {
37 context = new DefaultStateContext();
38 }
39
40 /**
41 * Creates a new instance which uses the specified {@link StateContextFactory}
42 * to create the single instance.
43 *
44 * @param contextFactory the {@link StateContextFactory} to use to create
45 * the singleton instance.
46 */
47 public SingletonStateContextLookup(StateContextFactory contextFactory) {
48 if (contextFactory == null) {
49 throw new NullPointerException("contextFactory");
50 }
51 context = contextFactory.create();
52 }
53
54 public StateContext lookup(Object[] eventArgs) {
55 return context;
56 }
57 }