Java线程2

线程的几个方法：

1. join()  线程的强制执行

    当主线程在执行时，子线程执行join方法，那么子线程就会强制执行，直到子线程执行结束，主线程才会继续执行

    

package thread;public class TestThreadJoin {public static void main(String[] args) throws InterruptedException {MyThread2 th = new MyThread2();th.start();for(int i=0; i<50; i++){System.out.println(Thread.currentThread().getName() + ":" + i);if(i>20){th.join();}}}}class MyThread2 extends Thread{public void run(){for(int i=0; i<50; i++){System.out.println(Thread.currentThread().getName() + ":" + i);}}}

执行结果：

main:0Thread-0:0main:1Thread-0:1main:2Thread-0:2main:3Thread-0:3main:4Thread-0:4main:5Thread-0:5main:6Thread-0:6main:7Thread-0:7main:8Thread-0:8main:9Thread-0:9main:10Thread-0:10main:11Thread-0:11main:12Thread-0:12main:13Thread-0:13main:14Thread-0:14main:15Thread-0:15main:16Thread-0:16main:17Thread-0:17main:18Thread-0:18main:19Thread-0:19main:20Thread-0:20main:21Thread-0:21Thread-0:22Thread-0:23Thread-0:24Thread-0:25Thread-0:26Thread-0:27Thread-0:28Thread-0:29Thread-0:30Thread-0:31Thread-0:32Thread-0:33Thread-0:34Thread-0:35Thread-0:36Thread-0:37Thread-0:38Thread-0:39Thread-0:40Thread-0:41Thread-0:42Thread-0:43Thread-0:44Thread-0:45Thread-0:46Thread-0:47Thread-0:48Thread-0:49main:22main:23main:24main:25main:26main:27main:28main:29main:30main:31main:32main:33main:34main:35main:36main:37main:38main:39main:40main:41main:42main:43main:44main:45main:46main:47main:48main:49

2. sleep() 线程的睡眠

    正在执行的线程，可以通过sleep() 方法，让线程沉睡指定的时间

3. yield() 线程的礼让

     线程之间的礼让，如A线程执行该方法，那么就会让B线程执行一会；B线程执行该方法，那么就会让A线程执行一会

     

package thread;public class TestThreadJoin {public static void main(String[] args) throws InterruptedException {MyThread2 th1 = new MyThread2();MyThread2 th2 = new MyThread2();th1.start();th2.start();}}class MyThread2 extends Thread{public void run(){for(int i=0; i<50; i++){System.out.println(Thread.currentThread().getName() + ":" + i);if(i==10){System.out.println("礼让");Thread.yield();}}}}

执行结果：

Thread-0:0Thread-1:0Thread-1:1Thread-1:2Thread-1:3Thread-1:4Thread-1:5Thread-1:6Thread-1:7Thread-1:8Thread-1:9Thread-1:10礼让Thread-0:1Thread-0:2Thread-0:3Thread-1:11Thread-0:4Thread-1:12Thread-0:5Thread-1:13Thread-0:6Thread-1:14Thread-0:7Thread-1:15Thread-0:8Thread-1:16Thread-0:9Thread-1:17Thread-0:10礼让Thread-1:18Thread-0:11Thread-1:19Thread-0:12Thread-1:20Thread-0:13Thread-1:21Thread-0:14Thread-1:22Thread-0:15Thread-1:23Thread-0:16Thread-1:24Thread-0:17Thread-1:25Thread-0:18Thread-1:26Thread-0:19Thread-1:27Thread-0:20Thread-1:28Thread-0:21Thread-1:29Thread-0:22Thread-1:30Thread-0:23Thread-1:31Thread-0:24Thread-1:32Thread-0:25Thread-1:33Thread-0:26Thread-1:34Thread-0:27Thread-1:35Thread-0:28Thread-1:36Thread-0:29Thread-1:37Thread-0:30Thread-1:38Thread-0:31Thread-1:39Thread-0:32Thread-1:40Thread-0:33Thread-1:41Thread-0:34Thread-1:42Thread-0:35Thread-1:43Thread-0:36Thread-1:44Thread-0:37Thread-1:45Thread-0:38Thread-1:46Thread-0:39Thread-1:47Thread-0:40Thread-1:48Thread-0:41Thread-1:49Thread-0:42Thread-0:43Thread-0:44Thread-0:45Thread-0:46Thread-0:47Thread-0:48Thread-0:49