IP

IP

IP地址：InetAddress

• 唯一定位一台网络计算机

• 127.0.0.1:本机localhost

• ip地址的分类：

  • ipv4/ipv6

    • IPV4127.0.0.1 ，4个字节组成，0~255,42亿~：30亿都在北美，亚洲4亿，2011年就用尽

    • IPV6128位，8个无符号整数！abcde

      2001:100b:aaaa:0012:0000:0000:a2b3:1574

  • 公网(互联网)-私网(局域网)

    • ABCD类地址

    • 192.168.xx.xx，专门给组织内部使用的

• 域名:记忆Ip问题！

• IP：www.vip.com 万网

package com.hua;

import java.net.InetAddress;
import java.net.UnknownHostException;

public class TestInetAddress {
    public static void main(String[] args) {
        try {
            //查询本机地址
            InetAddress inetAddress1 = InetAddress.getByName("127.0.0.1");
            System.out.println(inetAddress1);
            InetAddress inetAddress3 = InetAddress.getByName("localhost");
            System.out.println(inetAddress3);
            InetAddress inetAddress4 = InetAddress.getLocalHost();
            System.out.println(inetAddress4);
            //查询网站IP地址
            InetAddress inetAddress2 = InetAddress.getByName("www.baidu.com");
            System.out.println(inetAddress2);
            //常用方法
            //System.out.println(inetAddress2.getAddress());
            System.out.println(inetAddress2.getHostAddress());//ip
            System.out.println(inetAddress2.getCanonicalHostName());//规范的名字
            System.out.println(inetAddress2.getHostName());//域名，或者自己电脑的名字
        } catch (UnknownHostException e) {
            e.printStackTrace();
        }
    }
}