Java--多线程处理

示例代码：

多线程，并设置优先级：

package signal;


class A  extends Thread{
    public void run(){
        for(int i=1;i<=3;i++){
            System.out.println("a" +i);
        }
    }
}
class B  extends Thread{
    public void run(){
        for(int i=1;i<=3;i++){
            System.out.println("b" +i);
        }
    }
}

class     C  extends Thread{
    public void run(){
        for(int i=1;i<=3;i++){
            System.out.println("c" +i);
        }
    }
}

public class first {
    public static void main (String args[]){
        A a =new A();
        B b =new B();
        C c =new C();
        
        a.setPriority(Thread.MAX_PRIORITY);
        b.setPriority(Thread.NORM_PRIORITY);
        c.setPriority(Thread.MIN_PRIORITY);
        
        a.start();
        b.start ();
        c.start ();

    }

}

测试结果：

优先级的设置并不是一定会遵循这个优先级，只是按照优先级的概率会大一些。

情景：

利用多线程，控制交通信号灯

设置交通信号灯：

package signal;

import java.awt.Color;

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

public class signalDemo extends JFrame implements Runnable  {
    JPanel red ,yellow ,green;
    JLabel time ,show;
    
    

    @Override
    public void run() {
        
        
    try{
        while(true){
            red.setBackground(Color.red);
            yellow.setBackground(Color.gray);
            green.setBackground(Color.gray);
            for(int i=3;i>0;i++){
                String s =Integer.toString(i);
                show.setText(s+"-stop-");
                Thread.sleep(1000);
            }
            yellow.setBackground(Color.gray);
            green.setBackground(Color.green);
            red.setBackground(Color.gray);
            for(int i=5;i>0;i--){
                String s =Integer.toString(i);
                show.setText(s+"-go-");
                Thread.sleep(1000);
            }

            yellow.setBackground(Color.yellow);
            green.setBackground(Color.gray);
            red.setBackground(Color.gray);
            for(int i=2;i>0;i--){
                String s =Integer.toString(i);
                show.setText(s+"-get slow-");
                Thread.sleep(1000);
            }
        }
    }
    catch(InterruptedException e){
        System.out.println(e);
    }
    }
    signalDemo(){
        this.getContentPane().setBackground(Color.black);
        this.setSize(100,260);
        this.setVisible(true);
        this.setLocationRelativeTo(null);
        
        
        red=new JPanel();
        red.setBackground(Color.red);

        green=new JPanel();
        green.setBackground(Color.green);

        yellow=new JPanel();
        yellow.setBackground(Color.yellow);
        
        setLayout(null);
        red.setBounds(40,20,40,40);
        add(red);

        green.setBounds(40,70,40,40);
        add(green);

        yellow.setBounds(40,120,40,40);
        add(yellow);
        
        time =new JLabel("Time remain ");
        time.setForeground(Color.white);
        time.setBounds(20,160,100,40);
        add(time);
        show =new JLabel("");
        show.setBounds(38,178,80,40);
        show.setForeground(Color.cyan);
        add(show);
    }
    
    public static void main(String args[]){
        signalDemo sn=new signalDemo();
        Thread task=new Thread(sn);
        task.start();
        
    }
    
}

测试结果：