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原文：http://blog.csdn.net/reboot123/article/details/22589621 本文來自 http://blog.csdn.net/liuxian13183/ ，引用必須注明出處！ 1、 A.join，在API中的解釋是，堵塞當(dāng)前線程B，直到A執(zhí)行完畢并死掉，再執(zhí)行B。 用一個(gè)小例子來說明吧 static class ThreadA extends Thread { @Override public void run() { // TODO Auto-generated method stub super.run(); for (int i = 0; i < 10; i++) { System.out.println("ThreadA" + i); } } } static class ThreadB extends Thread { ThreadA a; public ThreadB(ThreadA a) { // TODO Auto-generated constructor stub this.a = a; } @Override public void run() { // TODO Auto-generated method stub super.run(); System.out.println("ThreadB start"); try { a.join(); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } System.out.println("ThreadB end"); } } public static void main(String[] args) { ThreadA a = new ThreadA(); ThreadB b = new ThreadB(a); b.start(); a.start(); }執(zhí)行結(jié)果： ThreadB start
ThreadA0
ThreadA1
ThreadA2
ThreadA3
ThreadA4
ThreadA5
ThreadA6
ThreadA7
ThreadA8
ThreadA9
ThreadB end
首先b線程執(zhí)行，a線程join后，直接執(zhí)行完a，然后才執(zhí)行b，證實(shí)上述說法。 2、A.yield，A讓出位置，給B執(zhí)行，B執(zhí)行結(jié)束A再執(zhí)行。跟join意思正好相反！ static class ThreadA extends Thread { @Override public void run() { // TODO Auto-generated method stub super.run(); for (int i = 0; i < 10; i++) { System.out.println("ThreadA " + i); } } } static class ThreadB extends Thread { ThreadA a; public ThreadB(ThreadA a) { // TODO Auto-generated constructor stub this.a = a; } @Override public void run() { // TODO Auto-generated method stub super.run(); System.out.println("ThreadB start"); try { for (int i = 0; i < 10; i++) { if(i==2){ a.yield(); } System.out.println("ThreadB " + i); } } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } System.out.println("ThreadB end"); } } public static void main(String[] args) { ThreadA a = new ThreadA(); ThreadB b = new ThreadB(a); b.start(); a.start(); }執(zhí)行結(jié)果： ThreadB start
ThreadA 0
ThreadB 0
ThreadA 1
ThreadB 1
ThreadA 2
ThreadB 2
ThreadB 3
ThreadB 4
ThreadB 5
ThreadB 6
ThreadB 7
ThreadB 8
ThreadB 9
ThreadB end
ThreadA 3
ThreadA 4
ThreadA 5
ThreadA 6
ThreadA 7
ThreadA 8
ThreadA 9
首先B執(zhí)行，然后A執(zhí)行；在B的循環(huán)中，i=2時(shí)，A執(zhí)行yield；接著B執(zhí)行完，才輪到A執(zhí)行。 |
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