超时中断(www.javaeye.com/topic/551928)
有一个需求,就是当一个方法执行超时的时候就中断该方法.
java的超时实现,在网上搜到的大部分是:
方法1.(由于不能达到预想的目的 就不列出来了)
实现描述:使用一个守护线程作为计时器,并且在计时结束时抛出一个未检测异常。
方法2.
用join,就是在主线程里开一个子线程(t),在子线程里去处理超时任务,主线程t.join(3000),3000为要等待的时间(ms),如果子线程没有超时则正常继续执行,如果超时了则中断该子线程t.interrupt();
代码如下:
Java代码
public class ThreadTest {
public static void main(String[] args) {
CounterThread ct = new CounterThread(5000);
System.out.println("start...");
System.out.println("ct start...");
ct.start();
System.out.println("ct join...");
try {
ct.join(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println(ct.isAlive());
ct.interrupt();
System.out.println(ct.isAlive());
System.out.println("the result is " + ct.getResult());
}
}
class CounterThread extends Thread {
private int time;
public CounterThread(int time) {
this.time = time;
}
private int result;
public int getResult() {
return result;
}
public void run() {
try {
Thread.sleep(time);
System.out.println(Thread.currentThread().getName()
+ " is blocked for " + time + "ms");
} catch (InterruptedException ex) {
}
result = 5;
}
}
public class ThreadTest {
public static void main(String[] args) {
CounterThread ct = new CounterThread(5000);
System.out.println("start...");
System.out.println("ct start...");
ct.start();
System.out.println("ct join...");
try {
ct.join(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println(ct.isAlive());
ct.interrupt();
System.out.println(ct.isAlive());
System.out.println("the result is " + ct.getResult());
}
}
class CounterThread extends Thread {
private int time;
public CounterThread(int time) {
this.time = time;
}
private int result;
public int getResult() {
return result;
}
public void run() {
try {
Thread.sleep(time);
System.out.println(Thread.currentThread().getName()
+ " is blocked for " + time + "ms");
} catch (InterruptedException ex) {
}
result = 5;
}
}
这种方式是可以的,其实还有另外一种方式,就是
Java代码
public class TimeoutTest1 {
public static void main(String[] args) {
final ExecutorService service = Executors.newFixedThreadPool(1);
TaskThread taskThread = new TaskThread();
System.out.println("提交任务...begin");
Future<Object> taskFuture = service.submit(taskThread);
System.out.println("提交任务...end");
try {
System.out.println("get .... begin");
Object re = taskFuture.get(1000, TimeUnit.MILLISECONDS);
System.out.println(re);
System.out.println("get .... end");
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
} catch (TimeoutException e) {
System.out.println("超时 取消任务");
taskFuture.cancel(true);
System.out.println("超时 取消任务OK");
}finally{
System.out.println("关闭服务");
service.shutdown();
System.out.println("关闭服务OK");
}
}
}
class TaskThread implements Callable<Object> {
public Object call() throws Exception {
String result = "空结果";
try {
System.out.println("任务开始....");
Thread.sleep(5000);
result = "正确结果";
System.out.println("任务结束....");
} catch (Exception e) {
System.out.println("Task is interrupted!");
}
return result ;
}
}
