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