Java如何监视线程的状态？

在Java编程中，如何监视线程的状态？

以下示例演示如何通过扩展Thread类并使用currentThread.getName()方法来监视线程的状态。

package com.yiibai;

class MyThread2 extends Thread { boolean waiting = true; boolean ready = false; MyThread2() { } public void run() { String thrdName = Thread.currentThread().getName(); System.out.println(thrdName + " starting."); while (waiting) System.out.println("waiting:" + waiting); System.out.println("waiting..."); startWait(); try { Thread.sleep(1000); } catch (Exception exc) { System.out.println(thrdName + " interrupted."); } System.out.println(thrdName + " terminating."); } synchronized void startWait() { try { while (!ready) wait(); } catch (InterruptedException exc) { System.out.println("wait() interrupted"); } } synchronized void notice() { ready = true; notify(); } } public class MonitoringThread { public static void main(String args[]) throws Exception { MyThread2 thrd = new MyThread2(); thrd.setName("MyThread #1"); showThreadStatus(thrd); thrd.start(); Thread.sleep(50); showThreadStatus(thrd); thrd.waiting = false; Thread.sleep(50); showThreadStatus(thrd); thrd.notice(); Thread.sleep(50); showThreadStatus(thrd); while (thrd.isAlive()) System.out.println("alive"); showThreadStatus(thrd); } static void showThreadStatus(Thread thrd) { System.out.println(thrd.getName() + " Alive:=" + thrd.isAlive() + " State:=" + thrd.getState()); } } 

Java

上述代码示例将产生以下结果 -

alive
alive
alive
alive
alive
.............  省略了一大波数据 ...............
alive
alive
MyThread #1 terminating.
alive
alive
alive
alive
alive
alive
alive
MyThread #1  Alive:=false State:=TERMINATED