thread.join() 的用法

来源：互联网发布：2018mpacc知乎编辑：程序博客网时间：2024/04/30 22:46

java Thread中， join() 方法是让调用该方法的主线程执行run()时暂时卡住，等run()执行完成后，主线程再调用执行join()后面的代码。示例：

class ThreadTesterA implements Runnable {private int counter;@Overridepublic void run() {while (counter <= 10) {System.out.print("Counter = " + counter + " ");counter++;}System.out.println();}}class ThreadTesterB implements Runnable {private int i;@Overridepublic void run() {while (i <= 10) {System.out.print("i = " + i + " ");i++;}System.out.println();}}public class ThreadTester {public static void main(String[] args) throws InterruptedException {Thread t1 = new Thread(new ThreadTesterA());Thread t2 = new Thread(new ThreadTesterB());t1.start();t1.join(); // wait t1 to be finishedt2.start();t2.join(); // in this program, this may be removed}}如果去掉t1.join()这个语句过后， 输出的顺序是乱的， 加上这个语句后， 就会按照顺序输出，  从某种意义上说实现了同步。

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