網路程式設計—IP

IP地址： InetAddress

• 唯一定位的網路上的計算機

• 127.0.0.1 ；本機Locathost

• ip地址分類

  • ipv4/ipv6

    • IPV4 127.0.0.1 , 0~255, 42億

    • IPV6 128位 8個無符號整數

• 公網(網際網路)—私網(區域網)

​ ABCD類地址

​ 192.168.XX.XX 專門給組織內部使用

• 域名：記憶問題

  • IP

package com.deng.lesson01;

import java.net.InetAddress;
import java.net.UnknownHostException;
//測試IP
public class TestInetAddress {
    public static void main(String[] args) {
        try {
            //查詢本機地址
            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);
            
            //查詢網站IP地址
            InetAddress inetAddress2 = InetAddress.getByName("www.baidu.com");
            System.out.println(inetAddress2);

            //常用方法
            //System.out.println(inetAddress1.getAddress());
            System.out.println(inetAddress2.getCanonicalHostName());//規範的名字
            System.out.println(inetAddress3.getHostAddress());//IP
            System.out.println(inetAddress4.getHostName());//域名 或者本機的名字
        }catch (UnknownHostException e){
          e.printStackTrace();
        }
    }
}