public class TestJoin {
  public static void main(String[] args) {
    MyThread2 t1 = new MyThread2("abcde");
    t1.start();
    try {
    	//join方法為合併執行緒本來是主執行緒和t1一起執行，呼叫join後會合併t1等到t1執行完後再執行主執行緒
    	t1.join();
    } catch (InterruptedException e) {}
    	
    for(int i=1;i<=10;i++){
      System.out.println("i am main thread");
    }
  }
}
class MyThread2 extends Thread {
  MyThread2(String s){
  	super(s);
  }
  
  public void run(){
    for(int i =1;i<=10;i++){
      System.out.println("i am "+getName());
      try {
      	//使執行緒等待1s後再執行
      	sleep(1000);
      } catch (InterruptedException e) {
      	return;
      }
    }
  }
}
 

執行結果：

i am abcde
i am abcde
i am abcde
i am abcde
i am abcde
i am abcde
i am abcde
i am abcde
i am abcde
i am abcde
i am main thread
i am main thread
i am main thread
i am main thread
i am main thread
i am main thread
i am main thread
i am main thread
i am main thread
i am main thread

public class TestYield {
  public static void main(String[] args) {
    MyThread3 t1 = new MyThread3("t1");
    MyThread3 t2 = new MyThread3("t2");
    t1.start(); t2.start();
  }
}
class MyThread3 extends Thread {
  MyThread3(String s){super(s);}
  public void run(){
    for(int i =1;i<=100;i++){
      System.out.println(getName()+": "+i);
      if(i%10==0){
      	//yield方法是當前執行緒讓出一小會兒，如此處當i=10時執行到10的t1或t2會換成另一個執行緒執行
      	//但並不表示一定會換隻是概率較大
        yield();
      }
    }
  }
}
 

t1: 1
t1: 2
t1: 3
t1: 4
t1: 5
t1: 6
t1: 7
t1: 8
t1: 9
t1: 10
t2: 1
t2: 2
t2: 3
t2: 4
t2: 5
t2: 6
t2: 7
t2: 8
t2: 9
t2: 10
t2: 11
t2: 12
t2: 13
t2: 14
t2: 15
t2: 16
t2: 17
t2: 18
t2: 19
t2: 20
t2: 21
t2: 22
t2: 23
t2: 24
t2: 25
t2: 26
t2: 27
t2: 28
t2: 29
t2: 30
t2: 31
t2: 32
t2: 33
t2: 34
t2: 35
t2: 36
t2: 37
t2: 38
t2: 39
t2: 40
t2: 41
t2: 42
t2: 43
t2: 44
t2: 45
t2: 46
t2: 47
t2: 48
t2: 49
t2: 50
t2: 51
t2: 52
t2: 53
t2: 54
t2: 55
t2: 56
t2: 57
t2: 58
t2: 59
t2: 60
t2: 61
t2: 62
t2: 63
t2: 64
t2: 65
t2: 66
t2: 67
t2: 68
t2: 69
t2: 70
t2: 71
t2: 72
t2: 73
t2: 74
t2: 75
t2: 76
t2: 77
t2: 78
t2: 79
t2: 80
t2: 81
t2: 82
t2: 83
t2: 84
t2: 85
t2: 86
t2: 87
t2: 88
t2: 89
t2: 90
t2: 91
t2: 92
t2: 93
t2: 94
t2: 95
t2: 96
t2: 97
t2: 98
t2: 99
t2: 100
t1: 11
t1: 12
t1: 13
t1: 14
t1: 15
t1: 16
t1: 17
t1: 18
t1: 19
t1: 20
t1: 21
t1: 22
t1: 23
t1: 24
t1: 25
t1: 26
t1: 27
t1: 28
t1: 29
t1: 30
t1: 31
t1: 32
t1: 33
t1: 34
t1: 35
t1: 36
t1: 37
t1: 38
t1: 39
t1: 40
t1: 41
t1: 42
t1: 43
t1: 44
t1: 45
t1: 46
t1: 47
t1: 48
t1: 49
t1: 50
t1: 51
t1: 52
t1: 53
t1: 54
t1: 55
t1: 56
t1: 57
t1: 58
t1: 59
t1: 60
t1: 61
t1: 62
t1: 63
t1: 64
t1: 65
t1: 66
t1: 67
t1: 68
t1: 69
t1: 70
t1: 71
t1: 72
t1: 73
t1: 74
t1: 75
t1: 76
t1: 77
t1: 78
t1: 79
t1: 80
t1: 81
t1: 82
t1: 83
t1: 84
t1: 85
t1: 86
t1: 87
t1: 88
t1: 89
t1: 90
t1: 91
t1: 92
t1: 93
t1: 94
t1: 95
t1: 96
t1: 97
t1: 98
t1: 99
t1: 100