java怎么判断线程结束,java 多线程全部结束判断方法
1.join()
如果是一个线程，可以使用此方法，多个不合适
2.CountDownLatch
此为并发计数器，每个线程结束后减一(countDown())，countDownLatch.await();//等待所有子线程执行完
public class ImportThread extends Thread {
private CountDownLatch threadsSignal;
public ImportThread(CountDownLatch threadsSignal) {
this.threadsSignal = threadsSignal;
}
@Override
public void run() {
System.out.println(Thread.currentThread().getName() + "开始...");
//Do somethings
threadsSignal.countDown();//线程结束时计数器减1
System.out.println(Thread.currentThread().getName() + "结束. 还有" + threadsSignal.getCount() + " 个线程");
}
}
CountDownLatch threadSignal = new CountDownLatch(threadNum);//初始化countDown
for (int ii = 0; ii < threadNum; ii++) {//开threadNum个线程
final Iterator itt = it.get(ii);
Thread t = new ImportThread(itt,sql,threadSignal);
t.start();
}
threadSignal.await();//等待所有子线程执行完
System.out.println(Thread.currentThread().getName() + "结束.");//打印结束标记
3.线程池ThreadPoolExecutor的shutdown与awaitTermination方法
executor.shutdown();//只是不能再提交新任务，等待执行的任务不受影响
try {
boolean loop = true;
do { //等待所有任务完成
loop = !executor.awaitTermination(2, TimeUnit.SECONDS); //阻塞，直到线程池里所有任务结束
} while(loop);
} catch (InterruptedException e) {
e.printStackTrace();
}
//
或者
exe.shutdown();
System.out.println("shutdown()：启动一次顺序关闭，执行以前提交的任务，但不接受新任务。");
while(true){
if(exe.isTerminated()){
System.out.println("所有的子线程都结束了！");
break;
}
Thread.sleep(1000);
}
1.join() 如果是一个线程，可以使用此方法，多个不合适 2.CountDownLatch 此为并发计数器，每个线程结束后减一(countDown())，countDownLatch.await();//等待所有子线程执行完 public class ImportThread extends Thread { private CountDownLatch threadsSignal; public ImportThread(CountDownLatch threadsSignal) { this.threadsSignal = threadsSignal; } @Override public void run() { System.out.println(Thread.currentThread().getName() + "开始..."); //Do somethings threadsSignal.countDown();//线程结束时计数器减1 System.out.println(Thread.currentThread().getName() + "结束. 还有" + threadsSignal.getCount() + " 个线程"); } } CountDownLatch threadSignal = new CountDownLatch(threadNum);//初始化countDown for (int ii = 0; ii < threadNum; ii++) {//开threadNum个线程 final Iterator itt = it.get(ii); Thread t = new ImportThread(itt,sql,threadSignal); t.start(); } threadSignal.await();//等待所有子线程执行完 System.out.println(Thread.currentThread().getName() + "结束.");//打印结束标记 3.线程池ThreadPoolExecutor的shutdown与awaitTermination方法 executor.shutdown();//只是不能再提交新任务，等待执行的任务不受影响 try { boolean loop = true; do { //等待所有任务完成 loop = !executor.awaitTermination(2, TimeUnit.SECONDS); //阻塞，直到线程池里所有任务结束 } while(loop); } catch (InterruptedException e) { e.printStackTrace(); } // 或者 exe.shutdown(); System.out.println("shutdown()：启动一次顺序关闭，执行以前提交的任务，但不接受新任务。"); while(true){ if(exe.isTerminated()){ System.out.println("所有的子线程都结束了！"); break; } Thread.sleep(1000); }