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锁定老帖子 主题：不可能完成任务？Thread的超时自动终止
精华帖 (0) :: 良好帖 (2) :: 新手帖 (1) :: 隐藏帖 (0)
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发表时间：2009-05-05
C_J 写道
public static void execute(Thread task, long timeout) throws TimeoutException {
task.start();
try {
task.join(timeout);
} catch (InterruptedException e) {
/* if somebody interrupts us he knows what he is doing */
}
if (task.isAlive()) {
task.interrupt();
throw new TimeoutException();
}
}
这种办法不能满足楼主的需求么？（不能完全保证时间的精确） 看到楼主实验了，运行不成功吗？ join是等待线程结束，timeout设置等待时间，如果超时，则线程进入调度。查了下JDK对wait(long)的注释是： 引用 The specified amount of real time has elapsed, more or less.The thread <var>T</var> is then removed from the wait set for this object and re-enabled for thread scheduling. interrupt();官方有这样一段解释： 引用 * <p> Unless the current thread is interrupting itself, which is
* always permitted, the {@link #checkAccess() checkAccess} method * of this thread is invoked, which may cause a {@link * SecurityException} to be thrown. 弱弱的问句“影子线程”不用interrupt()吗？ 希望对楼主有所帮助！ 这个我上边有例子试验过了，不行 |
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发表时间：2009-05-05
为什么？
if (task.isAlive()) { task.interrupt(); throw new TimeoutException(); } isAlive不进去么？ |
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发表时间：2009-05-05
看具体情况吧，可以考虑用stop
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发表时间：2009-05-09
这种情况，更适合使用进程而不是线程。
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发表时间：2009-05-09
最后修改：2009-05-09
public static void main(String[] args) {
timeout(5);
}
public static void timeout(long time) {
ExecutorService executor = Executors.newSingleThreadExecutor();
Future<String> future = executor.submit(new Callable<String>() {
@Override
public String call() throws Exception {
Thread.sleep(10000);
return null;
}
});
try {
future.get(time, TimeUnit.MILLISECONDS);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ExecutionException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (TimeoutException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
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发表时间：2009-05-11
最后修改：2009-05-11
public static void main(String[] args) {
final ScheduledExecutorService scheduler = Executors
.newScheduledThreadPool(2);
final Runnable beeper = new Runnable() {
int count = 0;
public void run() {
System.out.println(new Date() + " beep " + (++count));
}
};
// 1秒钟后运行，并每隔2秒运行一次
final ScheduledFuture<?> beeperHandle = scheduler.scheduleAtFixedRate(
beeper, 1, 2, TimeUnit.SECONDS);
// 2秒钟后运行，并每次在上次任务运行完后等待5秒后重新运行
final ScheduledFuture<?> beeperHandle2 = scheduler
.scheduleWithFixedDelay(beeper, 2, 5, TimeUnit.SECONDS);
// 30秒后结束关闭任务，并且关闭Scheduler
scheduler.schedule(new Runnable() {
public void run() {
beeperHandle.cancel(true);
beeperHandle2.cancel(true);
scheduler.shutdown();
}
}, 30, TimeUnit.SECONDS);
}
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发表时间：2009-05-11
kowen 写道 vvggsky 写道 import static java.util.concurrent.TimeUnit.*;
class BeeperControl {
private final ScheduledExecutorService scheduler =
Executors.newScheduledThreadPool(1);
public void beepForAnHour() {
final Runnable beeper = new Runnable() {
public void run() { System.out.println("beep"); }
};
final ScheduledFuture<?> beeperHandle =
scheduler.scheduleAtFixedRate(beeper, 10, 10, SECONDS);
scheduler.schedule(new Runnable() {
public void run() { beeperHandle.cancel(true); }
}, 60 * 60, SECONDS);
}
}
不行呢？为了省时，我把TimeUnit变成了MILLISECONDS
import java.util.concurrent.*;
public class BeeperControl {
private final ScheduledExecutorService scheduler =
Executors.newScheduledThreadPool(1);
public void beepForAnHour() {
final Runnable beeper = new Runnable() {
public void run() {
//业务
while(true)
System.out.println("do my task");
}
};
final ScheduledFuture<?> beeperHandle =
scheduler.scheduleAtFixedRate(beeper, 10, 10, TimeUnit.MILLISECONDS);
scheduler.schedule(new Runnable() {
public void run() {
beeperHandle.cancel(true);
System.out.println("task canceled");
}
}, 60 * 60, TimeUnit.MILLISECONDS);
}
public static void main(String args[]){
BeeperControl b = new BeeperControl();
b.beepForAnHour();
}
}
结果输出是 do my task do my task do my task do my task …… 把其中beeper 方法中的while (true)去掉即可 |
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发表时间：2009-05-11
利用ScheduledThreadPoolExecutor来执行runnable,得到future后调get(long timeout, TimeUnit unit) 就可以了
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发表时间：2009-05-12
mesmes 写道 kowen 写道 vvggsky 写道 import static java.util.concurrent.TimeUnit.*;
class BeeperControl {
private final ScheduledExecutorService scheduler =
Executors.newScheduledThreadPool(1);
public void beepForAnHour() {
final Runnable beeper = new Runnable() {
public void run() { System.out.println("beep"); }
};
final ScheduledFuture<?> beeperHandle =
scheduler.scheduleAtFixedRate(beeper, 10, 10, SECONDS);
scheduler.schedule(new Runnable() {
public void run() { beeperHandle.cancel(true); }
}, 60 * 60, SECONDS);
}
}
不行呢？为了省时，我把TimeUnit变成了MILLISECONDS
import java.util.concurrent.*;
public class BeeperControl {
private final ScheduledExecutorService scheduler =
Executors.newScheduledThreadPool(1);
public void beepForAnHour() {
final Runnable beeper = new Runnable() {
public void run() {
//业务
while(true)
System.out.println("do my task");
}
};
final ScheduledFuture<?> beeperHandle =
scheduler.scheduleAtFixedRate(beeper, 10, 10, TimeUnit.MILLISECONDS);
scheduler.schedule(new Runnable() {
public void run() {
beeperHandle.cancel(true);
System.out.println("task canceled");
}
}, 60 * 60, TimeUnit.MILLISECONDS);
}
public static void main(String args[]){
BeeperControl b = new BeeperControl();
b.beepForAnHour();
}
}
结果输出是 do my task do my task do my task do my task …… 把其中beeper 方法中的while (true)去掉即可 设置while(true)是为了超时啊，不用while(true)当然可以了，瞬间就执行完了 |
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发表时间：2009-05-13
还在讨论呢，还是那句话，不可能，除非把大的任务分解为很小的任务，然后用标量来判断。
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