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Java多线程其他

1.interrupt()方法

  interrupt方法不会真正中断线程,它只会清楚线程的wait,sleep,join的受阻状态,时线程重新获得CPU的执行权。

  此时如果再次调用线程的wait,sleep,join方法,将会抛出一个InterruptedException异常

package threadinterrupt;

public class InterruptDemo {
	public static void main(String[] args) throws InterruptedException {
		
		Thread t = new Thread(new Runnable() {
			private boolean flag = true;
			@Override
			public void run() {
				synchronized (this) {
					int i = 1;
					while(flag){

						System.out.println("=========" + i++ + "=========");
						if (i > 10) {
							try {
								System.out.println("子线程将停止执行");
								i =0;
								wait();
							} catch (InterruptedException e) {
								System.out.println("第二次调用wait()时抛出异常");
								e.printStackTrace();
								break;
							}
						}
					}
				}
			}
		});

		t.start();
		Thread.sleep(2000);
		t.interrupt();
		System.out.println("子线程将继续执行");
	}
}

  

2.join()方法,t1.join方法代表着当前线程放弃CPU执行资格,需要等到t1执行完毕时才能获得CPU执行资格

package threadinterrupt;

import java.lang.Thread.State;

public class ThreadJoin {
	public static void main(String[] args) throws InterruptedException {
		Runnable r = new  Runnable() {
			
			@Override
			public void run() {
				for (int i = 0; i < 1000; i++) {
					System.out.println(Thread.currentThread().getName()+":========"+i+"========");
				}
			}
		};
		
		Thread t1 = new Thread(r);
		Thread t2 = new Thread(r);
		t1.start();
		t2.start();
		
//		System.out.println("主线程需要等到t1执行完毕才会执行");
//		t1.join();
		
		if(t1.getState() == State.RUNNABLE){
			System.out.println("【没有】t1.join()时这句话会被执行");
		}
		
		if(t1.getState() == State.TERMINATED){
			System.out.println("【有】t1.join()时这句话会被执行");
		}
	}
}

  

3.yield()方法,暂停当前正在执行的线程对象,并执行其他线程,该方法不会让该线程放弃CPU的执行权,该线程任然可以争夺CPU执行权

package threadinterrupt;

public class ThreadYield {
	public static void main(String[] args) {
		Runnable r = new Runnable() {

			@Override
			public void run() {
				for (int i = 0; i < 1000; i++) {
					System.out.println(Thread.currentThread().getName()
							+ ":========" + i + "========");
					Thread.yield();
				}
			}
		};

		Thread t1 = new Thread(r);
		Thread t2 = new Thread(r);
		
		System.out.println("在子线程的run方法中添加Thread.yield();两个线程将会交替(不是绝对交替)");
		t1.start();
		t2.start();

	}
}

  

4.setDaemon(boolean on)方法,将该线程标记为守护线程或用户线程。

5.setPriority(int newPriority) 更改线程的优先级(1-10)数字越大,优先级越高

Java多线程其他