util/concurrent/Callable.java

/*
 * Written by Doug Lea with assistance from members of JCP JSR-166
 * Expert Group and released to the public domain, as explained at
 * http://creativecommons.org/publicdomain/zero/1.0/
 */

package java.util.concurrent;

/**
 * A task that returns a result and may throw an exception.
 * Implementors define a single method with no arguments called
 * {@code call}.
 *
 * <p>The {@code Callable} interface is similar to {@link
 * java.lang.Runnable}, in that both are designed for classes whose
 * instances are potentially executed by another thread.  A
 * {@code Runnable}, however, does not return a result and cannot
 * throw a checked exception.
 *
 * <p>The {@link Executors} class contains utility methods to
 * convert from other common forms to {@code Callable} classes.
 *
 * @see Executor
 * @since 1.5
 * @author Doug Lea
 * @param <V> the result type of method {@code call}
 */
@FunctionalInterface
public interface Callable<V> {
    /**
     * Computes a result, or throws an exception if unable to do so.
     *
     * @return computed result
     * @throws Exception if unable to compute a result
     */
    V call() throws Exception;
}
Revision:	1.12
Committed:	Wed Dec 4 12:30:14 2013 UTC (10 years, 6 months ago) by dl
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.11:	+1 -0 lines
Log Message:	add FunctionalInterface
#	User	Rev	Content
1	tim	1.1	/*
2	dl	1.2	* Written by Doug Lea with assistance from members of JCP JSR-166
3	dl	1.8	* Expert Group and released to the public domain, as explained at
4	jsr166	1.9	* http://creativecommons.org/publicdomain/zero/1.0/
5	tim	1.1	*/
6
7			package java.util.concurrent;
8
9			/**
10	dl	1.4	* A task that returns a result and may throw an exception.
11			* Implementors define a single method with no arguments called
12	jsr166	1.11	* {@code call}.
13	tim	1.1	*
14	jsr166	1.11	* <p>The {@code Callable} interface is similar to {@link
15	dl	1.5	* java.lang.Runnable}, in that both are designed for classes whose
16			* instances are potentially executed by another thread. A
17	jsr166	1.11	* {@code Runnable}, however, does not return a result and cannot
18	dl	1.5	* throw a checked exception.
19	tim	1.1	*
20	jsr166	1.10	* <p>The {@link Executors} class contains utility methods to
21	jsr166	1.11	* convert from other common forms to {@code Callable} classes.
22	dl	1.7	*
23	tim	1.1	* @see Executor
24	dl	1.5	* @since 1.5
25	dl	1.4	* @author Doug Lea
26	jsr166	1.11	* @param <V> the result type of method {@code call}
27	tim	1.1	*/
28	dl	1.12	@FunctionalInterface
29	tim	1.1	public interface Callable<V> {
30			/**
31			* Computes a result, or throws an exception if unable to do so.
32			*
33			* @return computed result
34			* @throws Exception if unable to compute a result
35			*/
36			V call() throws Exception;
37			}