exceptionevent.java

sea是一个基于seda模式的实现。这个设计模式将系统分为很多stage。每个stage分布不同的任务（基于线程池）。通过任务流的方式提高系统的效率。

/*
 * Copyright (c) 2003, The Regents of the University of California, through
 * Lawrence Berkeley National Laboratory (subject to receipt of any required
 * approvals from the U.S. Dept. of Energy). All rights reserved.
 */
package gov.lbl.dsd.sea.event;

import gov.lbl.dsd.sea.Stage;

/**
 * A generic runtime exception that can be thrown when a problem occurs within
 * {@link gov.lbl.dsd.sea.EventHandler#handle(java.lang.Object)}.
 * <p>
 * If appropriate, you can enqueue an instance of this class onto a stage.
 *
 * @author [e-mail]
 * @author $Author: hoschek3 $
 * @version $Revision: 1.2 $, $Date: 2004/07/22 18:04:54 $
 */
public class ExceptionEvent extends RuntimeException {

    protected Object causingEvent;
    protected Stage source;

    /**
     * Constructs a new exception.
     *
     * @param causingEvent
     *            the event that caused the exception.
     * @param source
     *            the stage that could not properly handle the causing event.
     */
    public ExceptionEvent(Object causingEvent, Stage source) {
        this(null, null, causingEvent, source);
    }

    /**
     * Constructs a new exception.
     *
     * @param  cause the cause (which is saved for later retrieval by the
     *         {@link #getCause()} method).  (A <tt>null</tt> value is
     *         permitted, and indicates that the cause is nonexistent or
     *         unknown.)
     * @param causingEvent
     *            the event that caused the exception.
     * @param source
     *            the stage that could not properly handle the causing event.
     */
    public ExceptionEvent(Throwable cause, Object causingEvent, Stage source) {
        this(null, cause, causingEvent, source);
    }

    /**
     * Constructs a new exception.
     *
     * @param message
     *            the detail message. The detail message is saved for later
     *            retrieval by the {@link #getMessage()}method.
     * @param  cause the cause (which is saved for later retrieval by the
     *         {@link #getCause()} method).  (A <tt>null</tt> value is
     *         permitted, and indicates that the cause is nonexistent or
     *         unknown.)
     * @param causingEvent
     *            the event that caused the exception.
     * @param source
     *            the stage that could not properly handle the causing event.
     */
    public ExceptionEvent(String message, Throwable cause, Object causingEvent, Stage source) {
        super(message, cause);
        this.causingEvent = causingEvent;
        this.source = source;
    }

    public Object getCausingEvent() {
        return this.causingEvent;
    }

    public Stage getSource() {
        return this.source;
    }


    public String toString() {
        String str = super.toString();
        if (getCausingEvent() != null) str = str + ", causingEventType=" + getCausingEvent().getClass().getName();
        if (getCausingEvent() != null) str = str + ", causingEvent=" + getCausingEvent();
        if (getSource() != null) str = str + ", source=" + getSource();
        return str;
    }

}