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.annotation;
21
22 import java.lang.annotation.ElementType;
23 import java.lang.annotation.Retention;
24 import java.lang.annotation.RetentionPolicy;
25 import java.lang.annotation.Target;
26
27 import org.apache.mina.statemachine.StateMachine;
28 import org.apache.mina.statemachine.event.Event;
29
30 /**
31 * Annotation used on methods to indicate that the method handles a specific
32 * kind of event when in a specific state.
33 *
34 * @author <a href="http://mina.apache.org">Apache MINA Project</a>
35 */
36 @Retention(RetentionPolicy.RUNTIME)
37 @Target(ElementType.METHOD)
38 @TransitionAnnotation(Transitions.class)
39 public @interface Transition {
40 /** The self transition */
41 public static final String SELF = "__self__";
42
43 /**
44 * Specifies the ids of one or more events handled by the annotated method. If
45 * not specified the handler method will be executed for any event.
46 *
47 * @return the ids of the handled events
48 */
49 String[] on() default Event.WILDCARD_EVENT_ID;
50
51 /**
52 * The id of the state or states that this handler applies to. Must be
53 * specified.
54 *
55 * @return the ids of the handled states
56 */
57 String[] in();
58
59 /**
60 * The id of the state the {@link StateMachine} should move to next after
61 * executing the annotated method. If not specified the {@link StateMachine}
62 * will remain in the same state.
63 *
64 * @return the id of the next state
65 */
66 String next() default SELF;
67
68 /**
69 * The weight used to order handler annotations which match the same event
70 * in the same state. Transitions with lower weight will be matched first. The
71 * default weight is 0.
72 *
73 * @return the weight used to order the handler
74 */
75 int weight() default 0;
76 }