/*
 
* Copyright (c) 1996, 2003, Oracle and/or its affiliates. All rights reserved.
 
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 
*
 
* This code is free software; you can redistribute it and/or modify it
 
* under the terms of the GNU General Public License version 2 only, as
 
* published by the Free Software Foundation.
  
Oracle designates this
 
* particular file as subject to the "Classpath" exception as provided
 
* by Oracle in the LICENSE file that accompanied this code.
 
*
 
* This code is distributed in the hope that it will be useful, but WITHOUT
 
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 
* FITNESS FOR A PARTICULAR PURPOSE.
  
See the GNU General Public License
 
* version 2 for more details (a copy is included in the LICENSE file that
 
* accompanied this code).
 
*
 
* You should have received a copy of the GNU General Public License version
 
* 2 along with this work; if not, write to the Free Software Foundation,
 
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 
*
 
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 
* or visit www.oracle.com if you need additional information or have any
 
* questions.
 
*/

package java.util;

/**
 
* <p>
 
* The root class from which all event state objects shall be derived.
 
* <p>
 
* All Events are constructed with a reference to the object, the "source",
 
* that is logically deemed to be the object upon which the Event in question
 
* initially occurred upon.
 
*
 
* @since JDK1.1
 
*/


public class EventObject implements java.io.Serializable {

    
private static final long serialVersionUID = 5516075349620653480L;

    
/**
     
* The object on which the Event initially occurred.
     
*/

    
protected transient Object
  
source
;

    
/**
     
* Constructs a prototypical Event.
     
*
     
* @param
    
sourceThe object on which the Event initially occurred.
     
* @exception
  
IllegalArgumentExceptionif source is null.
     
*/

    
public EventObject(Object source) {
        
if (source == null)
            
throw new IllegalArgumentException("null source");

        
this.source = source;
    
}

    
/**
     
* The object on which the Event initially occurred.
     
*
     
* @return
   
The object on which the Event initially occurred.
     
*/

    
public Object getSource() {
        
return source;
    
}

    
/**
     
* Returns a String representation of this EventObject.
     
*
     
* @return
  
A a String representation of this EventObject.
     
*/

    
public String toString() {
        
return getClass().getName() + "[source=" + source + "]";
    
}
}