线程：Java主线程等待子线程结束

使用Thread.join()方法：

 public class App {

     public static void main(String[] args) {
         testMain();
     }

     public static void testMain(){
         //实例化一个子线程
         Thread th = new Thread(new Runnable() {

             @Override
             public void run() {
                 for(int i=0; i<50; i++){
                     try {
                         Thread.sleep(1000);
                     } catch (InterruptedException e) {
                         e.printStackTrace();
                     }
                     System.out.println("我是子线程......"+i);
                 }
             }
         });

         //子线程开启
         th.start();

         //主线程
         for(int i=0; i<10; i++){
             try {
                 Thread.sleep(1000);
             } catch (InterruptedException e) {
                 e.printStackTrace();
             }
             System.out.println("主线程："+i);
         }

         try {
             //Thread.join
             th.join();
         } catch (InterruptedException e) {
             e.printStackTrace();
         }

         System.out.println("主线程结尾处.....");
     }

 }

运行结果：