1/*
2 *  Licensed to the Apache Software Foundation (ASF) under one or more
3 *  contributor license agreements.  See the NOTICE file distributed with
4 *  this work for additional information regarding copyright ownership.
5 *  The ASF licenses this file to You under the Apache License, Version 2.0
6 *  (the "License"); you may not use this file except in compliance with
7 *  the License.  You may obtain a copy of the License at
8 *
9 *     http://www.apache.org/licenses/LICENSE-2.0
10 *
11 *  Unless required by applicable law or agreed to in writing, software
12 *  distributed under the License is distributed on an "AS IS" BASIS,
13 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 *  See the License for the specific language governing permissions and
15 *  limitations under the License.
16 */
17
18package java.util;
19
20
21import java.io.Serializable;
22
23/**
24 * {@code EventObject}s represent events. Typically applications subclass this class to
25 * add event specific information.
26 *
27 * @see EventListener
28 */
29public class EventObject implements Serializable {
30
31    private static final long serialVersionUID = 5516075349620653480L;
32
33    @FindBugsSuppressWarnings("SE_TRANSIENT_FIELD_NOT_RESTORED")
34    protected transient Object source;
35
36    /**
37     * Constructs a new instance of this class.
38     *
39     * @param source
40     *            the object which fired the event.
41     */
42    public EventObject(Object source) {
43        if (source == null) {
44            throw new IllegalArgumentException("source == null");
45        }
46        this.source = source;
47    }
48
49    /**
50     * Returns the object which fired the event.
51     */
52    public Object getSource() {
53        return source;
54    }
55
56    /**
57     * Returns the string representation of this {@code EventObject}.
58     */
59    @Override public String toString() {
60        return getClass().getName() + "[source=" + source + ']';
61    }
62}
63