1 package com.xt.thinks21_2; 2  3 import java.util.concurrent.ExecutorService; 4 import java.util.concurrent.Executors; 5  6 /** 7  * java线程优先级测试 8  *  9  * @author Administrator10  *11  */12 public class ThreadPriorityTest implements Runnable {13     private int countDown = 5;14     private int priority;15     private volatile double d;16 17     public ThreadPriorityTest(int priority) {18         this.priority = priority;19     }20 21     @Override22     public String toString() {23         // TODO Auto-generated method stub24         return Thread.currentThread() + ":" + countDown;25     }26 27     @Override28     public void run() {29         // TODO Auto-generated method stub30         Thread.currentThread().setPriority(priority);31         while (true) {32             for (int i = 0; i < 10000000; i++) {33                 d += (Math.PI + Math.E) / (double) i;34                 if (i % 1000 == 0)35                     Thread.yield();36             }37             System.out.println(this);38             if (--countDown == 0)39                 return;40         }41     }42 43     public static void main(String[] args) {44         ExecutorService es = Executors.newCachedThreadPool();45         for (int i = 0; i < 5; i++)46             es.execute(new ThreadPriorityTest(Thread.MIN_PRIORITY));47         es.execute(new ThreadPriorityTest(Thread.MAX_PRIORITY));48         es.shutdown();49     }50 }

线程内部执行耗时操作的时候，设置线程优先级可以有效的调整线程执行顺序（无规律）。