View Javadoc
1   /*
2    * Copyright (c) 1994, 2013, Oracle and/or its affiliates. All rights reserved.
3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4    *
5    * This code is free software; you can redistribute it and/or modify it
6    * under the terms of the GNU General Public License version 2 only, as
7    * published by the Free Software Foundation.  Oracle designates this
8    * particular file as subject to the "Classpath" exception as provided
9    * by Oracle in the LICENSE file that accompanied this code.
10   *
11   * This code is distributed in the hope that it will be useful, but WITHOUT
12   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14   * version 2 for more details (a copy is included in the LICENSE file that
15   * accompanied this code).
16   *
17   * You should have received a copy of the GNU General Public License version
18   * 2 along with this work; if not, write to the Free Software Foundation,
19   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20   *
21   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22   * or visit www.oracle.com if you need additional information or have any
23   * questions.
24   */
25  
26  package java.lang;
27  
28  /**
29   * The <code>Runnable</code> interface should be implemented by any
30   * class whose instances are intended to be executed by a thread. The
31   * class must define a method of no arguments called <code>run</code>.
32   * <p>
33   * This interface is designed to provide a common protocol for objects that
34   * wish to execute code while they are active. For example,
35   * <code>Runnable</code> is implemented by class <code>Thread</code>.
36   * Being active simply means that a thread has been started and has not
37   * yet been stopped.
38   * <p>
39   * In addition, <code>Runnable</code> provides the means for a class to be
40   * active while not subclassing <code>Thread</code>. A class that implements
41   * <code>Runnable</code> can run without subclassing <code>Thread</code>
42   * by instantiating a <code>Thread</code> instance and passing itself in
43   * as the target.  In most cases, the <code>Runnable</code> interface should
44   * be used if you are only planning to override the <code>run()</code>
45   * method and no other <code>Thread</code> methods.
46   * This is important because classes should not be subclassed
47   * unless the programmer intends on modifying or enhancing the fundamental
48   * behavior of the class.
49   *
50   * @author  Arthur van Hoff
51   * @see     java.lang.Thread
52   * @see     java.util.concurrent.Callable
53   * @since   JDK1.0
54   */
55  @FunctionalInterface
56  public interface Runnable {
57      /**
58       * When an object implementing interface <code>Runnable</code> is used
59       * to create a thread, starting the thread causes the object's
60       * <code>run</code> method to be called in that separately executing
61       * thread.
62       * <p>
63       * The general contract of the method <code>run</code> is that it may
64       * take any action whatsoever.
65       *
66       * @see     java.lang.Thread#run()
67       */
68      public abstract void run();
69  }