servicestate.java

一个java方面的消息订阅发送的源码

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 *    please contact [e-mail].
 *
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 *
 * 5. Due credit should be given to the Exolab Project
 *    (http://www.exolab.org/).
 *
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 *
 * Copyright 1999-2004 (C) Exoffice Technologies Inc. All Rights Reserved.
 */
package org.exolab.jms.service;


/**
 * This class defines an enumeration of service states. 
 *
 * stopped      the service is not running
 * running      the service is running
 * 
 * @version     $Revision: 1.1 $ $Date: 2004/11/26 01:51:01 $
 * @author      <a href="mailto:[e-mail]">Jim Alateras</a>
 */
public final class ServiceState {

    /**
     * Instatiate instances related to each of the enumerations
     */
    public static final ServiceState STOPPED = new ServiceState("stopped");
    public static final ServiceState RUNNING = new ServiceState("running");

    private static int _upperSentinel = 0;

    /**
     * The state name
     */ 
    private String _state;

    /**
     * The ordinal value of the state
     */
    private int _ord;

    /**
     * Limit the creation scope of this object. All instances of this 
     * class are created at class initialisation time.
     *
     * @param state the state name
     */
    private ServiceState(String state) {
        _state = state;
        _ord = _upperSentinel++;
    }

    /**
     * Returns the ordinal value for this state
     *
     * @return the ordinal value of the state
     */
    public int getOrd() {
        return _ord; 
    }

    /**
     * Returns the name of this state
     *
     * @return the state name
     */
    public String toString() {
        return _state;
    }

    /**
     * Returns the number of states in this enumeration
     *
     * @return the number of states in the enumeration
     */
    public static int size() {
        return _upperSentinel; 
    }

    /**
     * Return true if the two specified object are of the same type 
     * and their ordinal values are the same.
     *
     * @param object the object to compare against
     * @return true if the two objects are equivalent
     */
    public boolean equals(Object object) {
        boolean equal = (object == this);
        if (!equal && object instanceof ServiceState) {
            equal = (_ord == ((ServiceState) object)._ord);
        }

        return equal;
    }

    /**
     * Return true if this object represents the 'running' state and false
     * otherwise
     *
     * @return true if this state is the 'running' state
     */
    public boolean isRunning() {
        return getOrd() == RUNNING.getOrd();
    }

    /**
     * Return true if this object represents the 'stopped' state and false
     * otherwise
     *
     * @return true if this state is the 'stopped' state
     */
    public boolean isStopped() {
        return getOrd() == STOPPED.getOrd();
    }

}