Java基础笔记_多线程

一.多线程

创建多线程方法一：

创建多线程继承Thread类+重写run(线程体)

package cn.inspur.myThread;

public class Rabbit extends Thread {
	@Override
	public void run() {
		for (int i = 0; i < 100; i++) {
			System.out.println("兔子跑了" + i + "步");
		}
	}

}

package cn.inspur.myThread;



public class Tortoise extends Thread {
	@Override
	public void run() {
		for (int i = 0; i < 100; i++) {
			System.out.println("\t乌龟跑了" + i + "步");
		}
	}

}

使用线程，创建子类对象+调用对象.start方法 线程的启动

package cn.inspur.myThread;



public class MyApp {
	public static void main(String[] args) {
		//创建子类对象
		Rabbit rab=new Rabbit();
		Tortoise tor=new Tortoise();
		//调用start方法
		rab.start();//不要调用run方法
		tor.start();
	}
}

创建线程方法二(使用Runnable,创建线程):

类实现Ruunnable接口+重写run（）

package cn.inspur.myThread;

public class Web12306 implements Runnable {
	private int num = 5;
	@Override
	public void run() {
		// TODO Auto-generated method stub
		while (true) {
			if (num <= 0)
				break;
		}
		System.out.println(Thread.currentThread().getName()+"抢到了"+num--);
	}
}

启动多线程 使用静态代理

1）创建真实角色
        2）创建代理角色+真实角色引用

3）调用.start()启动线程

package cn.inspur.myThread;

public class Web12306App {
	public static void main(String[] args) {
		Web12306 web = new Web12306();
		Thread t1 = new Thread(web,"01");
		Thread t2 = new Thread(web,"02");
		Thread t3 = new Thread(web,"03");
		t1.start();
		t2.start();
		t3.start();
	}
}

二. 线程状态

停止线程

1.自然终止:线程体使用的标识

2.外部干涉

package cn.inspur.myThread;

public class Demo01 {
	public static void main(String[] args) {
		Study study=new Study();
		new Thread(study).start();
		for (int i = 0; i < 100; i++) {
			if (50==i) {//外部干涉
				study.stop();
			}
			System.out.println("main..."+i);
		}
	}
}

class Study implements Runnable{
	
	//1.线程类中定义线程体使用的标志
	private boolean flag=true;

	@Override
	public void run() {
		// TODO Auto-generated method stub
		//2.线程体使用该标志
		while(flag){
			System.out.println("study.thread......");
		}
	}
	//3.对外提供方法改变标识
	public void stop() {
		this.flag=false;
		System.out.println("stoped");
	}
}

阻塞线程

join：合并线程

package cn.inspur.myThread;

public class JoinDemo01 extends Thread {
	

	public void run() {
		for (int i = 0; i < 1000; i++) {
			System.out.println("join...." + i);
		}
	}
	
	public static void main(String[] args) throws InterruptedException {
		JoinDemo01 demo01 = new JoinDemo01();
		Thread thread = new Thread(demo01);// 新生
		thread.start();// 就绪
		// CPU调度运行
		for (int i = 0; i < 1000; i++) {
			if (50 == i) {
				thread.join();//main方法阻塞，去执行join，join完成后再执行main
				System.out.print("**************");
			}
			System.out.println("\tmain...." + i);

		}
	}
}

Yield：暂停线程 静态方法（static）

package cn.inspur.myThread;

public class YieldDemo01 extends Thread {
	public void run() {
		for (int i = 0; i < 1000; i++) {
			System.out.println("Yield...." + i);
		}
	}
	public static void main(String[] args) throws InterruptedException {
		YieldDemo01 demo01 = new YieldDemo01();
		Thread thread = new Thread(demo01);// 新生
		thread.start();// 就绪
		// CPU调度运行
		for (int i = 0; i < 1000; i++) {
			if (0 == i%20) {
				Thread.yield();//main方法暂停，静态方法，下一个执行谁要看CPU
				System.out.print("**************");
			}
			System.out.println("\tmain...." + i);

		}
	}
}

sleep：延迟线程

package cn.inspur.myThread;

import java.sql.Date;
import java.text.SimpleDateFormat;

public class SleepDemo01 {
	public static void main(String[] args) throws InterruptedException {
		Date endTime=new Date(System.currentTimeMillis()+10*1000);
		long end=endTime.getTime();
		while(true){
			//输出
			System.out.println(new SimpleDateFormat("mm:ss").format(endTime));
			//等待一秒
			Thread.sleep(1000);
			//构建下一秒的时间
			endTime=new Date(endTime.getTime()-1000);
			//10秒内继续否则退出
			if(end-10000>endTime.getTime()){
				break;
			}
		}
	}
}