多线程：竞赛

要求：三个方块，同时出发，改变其在x轴上的位置，来观察其运动的快慢。

代码：

import java.awt.Color;
import java.util.Random;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

/**
 * 
 */

/**
 * @author: Annie
 * @date:2016年6月14日
 * @description:使用多线程
 */
public class Race extends Thread {
    String ThreadName;//记录线程的名字
    JLabel l;
    JPanel jp1,jp2,jp3;//显示三个矩形
    JFrame jf;
    public Race() {
        
        jp1 = new JPanel();
        jp1.setSize(20, 20);
        jp1.setBackground(Color.pink);
        jp1.setBounds(10, 40, 20, 20);

        jp2 = new JPanel();
        jp2.setSize(20, 20);
        jp2.setBackground(Color.BLUE);
        jp2.setBounds(10, 80, 20, 20);

        jp3 = new JPanel();
        jp3.setSize(20, 20);
        jp3.setBackground(Color.YELLOW);
        jp3.setBounds(10, 120, 20, 20);

        l = new JLabel("");
        l.setBounds(10, 10, 160, 200);
        
        jf = new JFrame("多线程赛跑例子");
        jf.setSize(400, 300);
        jf.setLayout(null);
        jf.add(l);
        jf.add(jp1);
        jf.add(jp2);
        jf.add(jp3);

        jf.setVisible(true);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    }
    @Override
    public void run() {
        //添加一个判断，如果是第一个线程执行runA,第二个则是RunB,第三个则是RunC;
        if(Thread.currentThread().getName() .equals("tA")){
            runA();
        }else if (Thread.currentThread().getName().equals("tB") ){
            runB();
        }else {
            runC();
        }
    }

    //分别控制三个矩形的x坐标
    public void runA(){
        Random random = new Random();
        int s = random.nextInt(200);//随机y坐标

        for (int i = -10; i <= 400; i+=2) {
            jp1.setBounds(i, s, 20, 20);
            try {
                Thread.sleep(50);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }

    public void runB(){
        Random random = new Random();
        int s = random.nextInt(300);//随机y坐标
        for (int i = -10; i <= 400;  i+=4) {
            jp2.setBounds(i, s, 20, 20);
            try {
                Thread.sleep(50);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

    }
    public void runC(){
        Random random = new Random();
        int s = random.nextInt(300);//随机y坐标
        for (int i = -10; i <= 400;  i+=6) {
            jp3.setBounds(i, s, 20, 20);
            try {
                Thread.sleep(50);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
    public static void main(String[] args) {
        Race r = new Race();
        Thread tA = new Thread(r);
        tA.setName("tA");
        tA.start();
        
        Thread tB = new Thread(r);
        tB.setName("tB");
        tB.start();
        
        Thread tC = new Thread(r);
        tC.setName("tC");
        tC.start();
    }

}

运行效果：