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   1.0

    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 }