package com.example;public class App {        public static void main(String[] args) {                DoDaemon d1 = new DoDaemon();        DoRunnable d2 = new DoRunnable("Sinny");                Thread t1 = new Thread(d1);        Thread t2 = new Thread(d2);        //设置为后台线程，        t1.setDaemon(true);                t1.start();        t2.start();//用户线程结束后，JVM自动退出，不再等待后台进程    }}

package com.example;public class DoDaemon implements Runnable{    @Override    public void run() {        for (int i = 0; i < 300; i++) {            try {                Thread.sleep(5);            } catch (InterruptedException e) {                e.printStackTrace();            }                        System.out.println("Hello__Deamon");        }    }}

package com.example;public class DoRunnable implements Runnable {    private String name;    public DoRunnable(String name) {        this.name = name;    }    @Override    public void run() {        for (int i = 0; i < 3; i++) {            try {                Thread.sleep(5);            } catch (InterruptedException e) {                e.printStackTrace();            }            System.out.println("Hello__" + this.name);        }    }}