Java——多线程基础

一、线程与进程概述

Java的线程是通过java.lang.Tread类来实现的，通过重写run()方法

二、实现线程两种方法：

1、继承Thread类

public class Demo03 {
    public static void main(String[] args) {
        Thread t1=new MyThread();
        t1.setName("线程1");
        t1.start();
        Thread t2=new MyThread();
        t2.setName("线程2");
        t2.start();
        String str=Thread.currentThread().getName();
        for (int i = 0; i <100 ; i++) {
            System.out.println("........."+str+"........."+i);
        }
    }
}
class MyThread extends Thread{
    @Override
    public void run() {
        String str=Thread.currentThread().getName();
        for (int i = 0; i <100 ; i++) {
            System.out.println("....MyThread......run()..."+str+"......."+i);
        }
    }
}

    2、实现Runnable接口

public class Demo02 {
    public static void main(String[] args) {
        Runnable3 r=new Runnable3();
        Thread t1=new Thread(r);
        Thread t2=new Thread(r);
        t1.start();
        t2.start();
        for (int i = 0; i < 100; i++) {
            String str=Thread.currentThread().getName();
            System.out.println("......Demo02......"+str+"......"+i);
        }
    }
}
class Runnable3 implements Runnable{

    @Override
    public void run() {
        for (int i = 0; i < 100; i++) {
            String str=Thread.currentThread().getName();
            System.out.println("....Runnable3..  ."+str+"....."+i);
        }

    }
}

三、线程状态及生命周期

 

public class Demo04 {
    public static void main(String[] args) {
        MyThread4 mt=new MyThread4();
        mt.start();
    }
}
class MyThread4 extends Thread{
    @Override
    public void run() {

        for (int i = 0; i <60 ; i++) {
            try {
//                阻塞
                this.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println("i="+i+"\t\t\t"+new Date());
            if(i==10){
                break;
            }
        }
    }
}

四、线程优先级

优先级高代表cpu会给你多分配点运行时间，优先级用数字表示，范围1-10，主线程默认优先级为5

方法：

.sleep(毫秒数)；时间结束，自动唤醒

.wait();需要唤醒