Java方法设置超时

我们在开发过程中可能会遇到这样的场景：在执行一个耗时操作的时候，如果在规定的时间内处理完成了，则返回正确的结果，否则视为超时任务，这个时候我们将不再等待（不再执行）该耗时操作，直接告诉调用者：这个任务由于耗时过多，被取消了。

import java.util.Random;import java.util.concurrent.Callable;import java.util.concurrent.ExecutionException;import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;import java.util.concurrent.FutureTask;import java.util.concurrent.TimeUnit;import java.util.concurrent.TimeoutException;public class TimeoutTest {    private static ExecutorService executorService = Executors.newSingleThreadExecutor();    /**     * @param args     */    public static void main(String[] args) {        // TODO Auto-generated method stub        long start = System.currentTimeMillis();        String result = timeoutMethod(5000);        System.out.println("方法实际耗时：" + (System.currentTimeMillis() - start) + "毫秒");        System.out.println("结果：" + result);        try {            Thread.sleep(8000);            long start1 = System.currentTimeMillis();            String result1 = timeoutMethod(5000);            System.out.println("方法实际耗时：" + (System.currentTimeMillis() - start1) + "毫秒");            System.out.println("结果：" + result1);        } catch (Exception e) {            // TODO: handle exception        }    }    /**     * 有超时时间的方法     * @param timeout     * @return     */    private static String timeoutMethod(int timeout) {        String result = "默认";        FutureTask<String> futureTask = new FutureTask<>(new Callable<String>() {            @Override            public String call() throws Exception {                return unknowMethod();            }        });        executorService.execute(futureTask);        try {            result = futureTask.get(timeout, TimeUnit.MILLISECONDS);        } catch (InterruptedException | ExecutionException | TimeoutException e) {            //e.printStackTrace();            futureTask.cancel(true);            result = "默认";        }        return result;    }    /**     * 这个方法的耗时不确定     * @return     */    private static String unknowMethod() {        Random random = new Random();        int time = (random.nextInt(10) + 1) * 1000;        System.out.println("任务将耗时： " + time + "毫秒");        try {            Thread.sleep(time);        } catch (Exception e) {            // TODO: handle exception        }        return "获得方法执行后的返回值";    }}

参考：http://blog.csdn.net/a1015088819/article/details/53099943