7.1（java学习笔记）InetAddress&InetSc…

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

public class TestNet {
    public static void main(String[] args) throws UnknownHostException {
        //InetAddress 封装了IP和DNS（域名）
        InetAddress localhost = InetAddress.getLocalHost();//返回代表本地InetAddress对象
        System.out.println(localhost.getHostName());//获取该该对象的IP域名     Ni
        System.out.println(localhost.getHostAddress());//获取该对象的IP地址  192.168.17.1
        InetAddress a = InetAddress.getByName("localhost");//返回该域名所代表的InetAddres对象
        System.out.println(a.getHostName());//获取该对象代表的域名               localhost
        System.out.println(a.getHostAddress());//获取该对象代表的IP地址 127.0.0.1
        InetAddress b = InetAddress.getByName("192.168.17.1");//返回该IP地址所代表的InetAddress对象
        System.out.println(b.getHostName());//返回该对象所代表域名    Ni
        System.out.println(b.getHostAddress());//返回该对象的IP地址 192.168.17.1
    }
}

Ni
192.168.17.1
localhost
127.0.0.1
Ni
192.168.17.1

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

public class TestNet {
    public static void main(String[] args) throws UnknownHostException {
        InetAddress b = InetAddress.getByName("www.baidu.com");
        System.out.println(b.getHostName());
        System.out.println(b.getHostAddress());
    }
}

运行结果：
www.baidu.com
119.75.217.109

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

public class TestNet {
    public static void main(String[] args) throws UnknownHostException {
        InetAddress b = InetAddress.getByName("119.75.217.109");
        System.out.println(b.getHostName());
        System.out.println(b.getHostAddress());
    }
}

运行结果；
119.75.217.109
119.75.217.109

import java.net.InetSocketAddress;
import java.net.UnknownHostException;

public class TestNet {
    public static void main(String[] args) throws UnknownHostException {
        //最好不要分配1024以下的端口
        InetSocketAddress i = new InetSocketAddress("localhost",2048);//初始化，域名|主机名|地址
        //InetSocketAddress e = new InetSocketAddress("127.0.0.1"，2049);
        System.out.println(i.getAddress().getHostName());
        System.out.println(i.getPort());//端口号
        InetAddress ia = i.getAddress();//返回一个InetAddress对象
        System.out.println(ia.getHostName());//后续就可以调用InetAddress中的方法对其操作 （主机名）
        System.out.println(ia.getHostAddress());//主机IP地址
    }
}

运行结果：
localhost
2048
localhost
127.0.0.1