java监控多个线程的实现

场景:需要启动多线程处理事情,而在所有事情做完之后,需要修改系统状态;那么如何判断所有线程(事情)都做完了呢?这就需要判断所有当前运行的线程状态了。
代码
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;

/** 测试监控类 */
public class WatchThread {

    
/** 测试函数 */
    
public void testThread() throws InterruptedException {
        
int threadNum = 10;
        
// 初始化countDown
        CountDownLatch threadSignal = new CountDownLatch(threadNum);
        
// 创建固定长度的线程池
        Executor executor = Executors.newFixedThreadPool(threadNum);
        
for (int i = 0; i < threadNum; i++) { // 开threadNum个线程
            Runnable task = new TestThread(threadSignal);
            
// 执行
            executor.execute(task);
        }
        threadSignal.await(); 
// 等待所有子线程执行完
        
// do work
        System.out.println(Thread.currentThread().getName() + "+++++++结束.");
    }

    
/** 测试函数 */
    
public static void main(String[] args) throws InterruptedException {
        WatchThread test 
= new WatchThread();
        test.testThread();
    }

    private class TestThread implements Runnable {
        
private CountDownLatch threadsSignal;

        
public TestThread(CountDownLatch threadsSignal) {
            
this.threadsSignal = threadsSignal;
        }

        
public void run() {
            System.out.println(Thread.currentThread().getName() 
+ "开始...");
            
// do shomething
            System.out.println("开始了线程::::" + threadsSignal.getCount());
            
// 线程结束时计数器减1
            threadsSignal.countDown();
            System.out.println(Thread.currentThread().getName() 
+ "结束. 还有"
                    
+ threadsSignal.getCount() + " 个线程");
        }
    }

}

 

posted @ 2010-10-15 20:25  MyFavorite  阅读(4702)  评论(0编辑  收藏  举报