Java线程学习笔记（一）-优快云博客

本文介绍了一个名为Counter的倒计时类，该类实现了Runnable接口并可通过Thread或ExecutorService进行调用。每个实例拥有唯一的线程ID，并能够显示当前倒计数值。

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入门，定义一个做倒计时的类，Counter，该类实现了Runnable接口，

package com.woxiaoe.study.thread;
/**
 * 倒计时类
 * @author 小e
 *
 * 2010-4-19 下午09:12:02
 */
public class Counter implements Runnable {
	
	private int countNum;
	private static int taskCount = 0;//线程id
	private final int taskId = taskCount++;
	
	public Counter(int countNum) {
		this.countNum = countNum;
	}
	
	public String show(){
		return "Id[" + taskId + "] countNum:" + countNum + "  ";
	}
	@Override
	public void run() {
		while(countNum-- > 0){
			System.out.print(show());
			Thread.yield();
		}
	}
	

}

测试代码，通过Thread来调用

package com.woxiaoe.study.thread;

import java.util.Random;

import junit.framework.TestCase;

public class TestCounter extends TestCase {
	public void testThread(){
		for(int i = 0; i < 5 ; i++){
			new Thread(new Counter(10)).start();
		}
	}

}

通过ExecutorService调用

public void testExecutor(){
		ExecutorService exec = Executors.newCachedThreadPool();
		for(int i = 0; i < 10 ; i++){
			exec.execute(new Counter(10));
		}
		exec.shutdown();
	}

Output：

Id[1] countNum:9 Id[0] countNum:9 Id[3] countNum:9 Id[2] countNum:9 Id[0] countNum:8 Id[1] countNum:8 Id[3] countNum:8 Id[1] countNum:7 Id[4] countNum:9 Id[1] countNum:6 Id[3] countNum:7 Id[3] countNum:6 Id[1] countNum:5 Id[3] countNum:5 Id[1] countNum:4 Id[3] countNum:4 Id[1] countNum:3 Id[3] countNum:3 Id[1] countNum:2 Id[3] countNum:2 Id[1] countNum:1 Id[3] countNum:1 Id[1] countNum:0 Id[3] countNum:0 Id[2] countNum:8 Id[2] countNum:7 Id[2] countNum:6 Id[2] countNum:5 Id[2] countNum:4 Id[2] countNum:3 Id[2] countNum:2 Id[2] countNum:1 Id[2] countNum:0