java信号量控制线程打印顺序的示例分享

import java.util.concurrent.semaphore;

public class threethread {

 public static void main(string[] args) throws interruptedexception {
  semaphore sempa = new semaphore(1);
  semaphore sempb = new semaphore(0);
  semaphore sempc = new semaphore(0);
  int n=100;
  thread threada = new printthread(n, sempa, sempb, "a");
  thread threadb = new printthread(n, sempb, sempc, "b");
  thread threadc = new printthread(n, sempc, sempa, "c");
  threada.start();
  threadb.start();
  threadc.start();
 }

 static class printthread extends thread{

  int n;
  semaphore cursemp;
  semaphore nextsemp;
  string name;

  public printthread(int n, semaphore cursemp, semaphore nextsemp, string name) {
   n = n;
   this.cursemp = cursemp;
   this.nextsemp = nextsemp;
   this.name = name;
  }

  public void run() {
   for (int i = 0; i < n; ++i) {
    try {
     cursemp.acquire();
     system.out.println(name);
     nextsemp.release();
    } catch (interruptedexception e) {
     thread.currentthread().interrupt();
    }
   }
  }

 }

}