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