Java多線程/啓動循環中的線程

Question

有人可以幫我解決這個多線程問題嗎？

程序應該用一個公共資源啓動三個線程。每個線程應打印一個增加的計數值。示例輸出如下所述。 T1，T2和T3是線程。

T1 T2 T3 

1 2 3  

4 5 6 

7 8 9 

我當前的代碼：

public class RunnableSample implements Runnable { 
    static int count = 0; 

    public void run() { 
     synchronized (this) { 
      count++; 
      System.out.println(
       "Current thread : Thread name :" + Thread.currentThread().getName() 
       + " Counter value :" + count 
      ); 
     } 
    } 
} 

//main method with for loop for switching between the threads 
public class ThreadInitiator { 
    public static void main(String[] args) { 
     RunnableSample runnableSample = new RunnableSample(); 

     Thread thread1 = new Thread(runnableSample, "T1"); 
     Thread thread2 = new Thread(runnableSample, "T2"); 
     Thread thread3 = new Thread(runnableSample, "T3"); 

     for (int i = 0; i < 9; i++) { 
      thread1.start(); 
      thread2.start(); 
      thread3.start(); 
     } 
    } 
} 

Answer 1

創建一個同步的方法來遞增的值。當一個方法被識別爲同步時，一次只有一個線程可以訪問它，其他線程在它們可以訪問該方法之前等待初始線程完成方法執行。

請檢查How to synchronize a static variable among threads running different instances of a class in java?