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Java > Open Source Codes > com > sun > corba > se > spi > orbutil > fsm > State


1 /*
2  * @(#)State.java 1.7 03/12/19
3  *
4  * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
5  * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
6  */
7
8 package com.sun.corba.se.spi.orbutil.fsm ;
9
10 /**
11  * This interface must be implemented by any class that is used as
12  * a state in a FSM. The FSM only needs the identity of this
13  * object, so all that is really needs is the default equals implementation.
14  * The toString() method should also be overridden to give a concise
15  * description or name of the state. The StateImpl class handles this.
16  * <P>
17  * Pre- and post- actions are taken only on completed transitions between
18  * different states. Assume that the FSM is in state A, and the FSM will
19  * transition to state B under input I with action X. If A != B and X completes
20  * successfully, then after X completes execution, A.postAction is executed,
21  * followed by B.preAction.
22  *
23  * @version @(#)State.java 1.7 03/12/19
24  * @author Ken Cavanaugh
25  */
26 public interface State
27 {
28     /** Method that defines action that occurs whenever this state is entered.
29     * Any exceptions thrown by this method are ignored.
30     */
31     void preAction( FSM fsm ) ;
32
33     /** Method that defines action that occurs whenever this state is exited.
34     * Any exceptions thrown by this method are ignored.
35     */
36     void postAction( FSM fsm ) ;
37 }
38
39 // end of State.java
40
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