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.statemachine.State;
23 import org.apache.mina.statemachine.StateMachine;
24
25 /**
26 * {@link StateContext} objects are used to store the current {@link State} and
27 * any application specific attributes for a specific client of a
28 * {@link StateMachine}. Since {@link StateMachine}s are singletons and shared
29 * by all clients using the {@link StateMachine} this is where client specific
30 * data needs to be stored.
31 *
32 * @author <a href="http://mina.apache.org">Apache MINA Project</a>
33 */
34 public interface StateContext {
35 /**
36 * @return the current {@link State}. This is only meant for internal use.
37 */
38 State getCurrentState();
39
40 /**
41 * Sets the current {@link State}. This is only meant for internal use.
42 * Don't call it directly!
43 *
44 * @param state the new current {@link State}.
45 */
46 void setCurrentState(State state);
47
48 /**
49 * Returns the value of the attribute with the specified key or
50 * <code>null</code>if not found.
51 *
52 * @param key the key.
53 * @return the value or <code>null</code>.
54 */
55 Object getAttribute(Object key);
56
57 /**
58 * Sets the value of the attribute with the specified key.
59 *
60 * @param key the key.
61 * @param value the value.
62 */
63 void setAttribute(Object key, Object value);
64 }