简单的1，2,3,4线程先后执行方式示例
1 package thread; 2 3 /** 4 * 线程的结合。 5 * 当一个线程需要等待另一个线程结束时，叫做线程的结合。 6 */ 7 public class JoinThread { 8 /** 自定义线程类 */ 9 static class ThreadA extends Thread{ 10 //线程的ID 11 private int ID = 0; 12 //线程运行时循环的次数 13 private int whileTimes = 0; 14 public ThreadA(int id, int times){ 15 this.ID = id; 16 this.whileTimes = times; 17 } 18 public void run(){ 19 System.out.println("ThreadA" + this.ID + " begin!"); 20 int i=0; 21 try { 22 //连续循环whileTimes次 23 while (i < this.whileTimes){ 24 System.out.println("ThreadA-" + this.ID + ": " + i++); 25 //sleep方法将当前线程休眠。 26 Thread.sleep(200); 27 } 28 } catch (InterruptedException e) { 29 } 30 31 System.out.println("ThreadA" + this.ID + " end!"); 32 } 33 } 34 public static void main(String[] args) { 35 //新建4个线程对象 36 Thread thread1 = new ThreadA(1, 3); 37 Thread thread2 = new ThreadA(2, 2); 38 Thread thread3 = new ThreadA(3, 2); 39 Thread thread4 = new ThreadA(4, 4); 40 //启动所有线程 41 System.out.println("Main method begin. To start 4 threads!"); 42 try { 43 thread1.start(); 44 thread1.join(); 45 thread2.start(); 46 thread2.join(); 47 thread3.start(); 48 thread3.join(); 49 thread4.start(); 50 thread4.join(); 51 } catch (InterruptedException e) { 52 // TODO: handle exception 53 } 54 55 //等待所有线程运行结束 56 57 //此时所有线程都运行结束 58 System.out.println("Main method end! All 4 threads are ended"); 59 } 60 }
多线程没有控制的时候，线程的任务不一定被java虚拟机交替进行的
