jdk与Eclipse环境搭建

当前下载的版本
https://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html

随后安装eclipse


附一个简单的多线程例子

public class Hello_Java {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		System.out.println("Hello Java and Hello World");
		UserThread t1,t2,t3,t4;
		t1=new UserThread("1");
		t2=new UserThread("2");
		t3=new UserThread("3");
		t4=new UserThread("4");

		t1.start();
		t2.start();
		t3.start();
		t4.start();
	}

}

class UserThread extends Thread{
	int sleeptime;
	public UserThread(String id) {
		super(id);
		sleeptime=(int)(Math.random()*1000);
		System.out.println("线程号: "+getName()+",睡眠"
				+sleeptime+"毫秒");
	}
	public void run(){
		try{
			Thread.sleep(sleeptime);
		}catch(InterruptedException e) {
			System.err.println("error"+e.toString());
		}
		
		System.out.println("运行的线程是："+getName());
	}
}

路漫漫其修远兮，吾将上下而求索！