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    /**
34     * The event source.
35     */
36    protected transient Object source;
37
38    /**
39     * Constructs a new instance of this class.
40     *
41     * @param source
42     *            the object which fired the event.
43     */
44    public EventObject(Object source) {
45        if (source != null) {
46            this.source = source;
47        } else {
48            throw new IllegalArgumentException();
49        }
50    }
51
52    /**
53     * Returns the event source.
54     *
55     * @return the object which fired the event.
56     */
57    public Object getSource() {
58        return source;
59    }
60
61    /**
62     * Returns the string representation of this {@code EventObject}.
63     *
64     * @return the string representation of this {@code EventObject}.
65     */
66    @Override
67    public String toString() {
68        return getClass().getName() + "[source=" + source + ']'; //$NON-NLS-1$
69    }
70}
71