根据主机来判断ip地址以及ip分类

MyIP

import java.net.Inet4Address;
import java.net.Inet6Address;
import java.net.InetAddress;
import java.util.Scanner;

public class MyIP {

  public static void main(String[] args) throws Exception {
		Scanner input=new Scanner(System.in);
		System.out.println("输入要判断IP地址的主机名（网站）：");
		String host=input.next();
		
		InetAddress address = InetAddress.getByName(host);
		System.out.println("IP: " + address.getHostAddress());
		switch (address.getAddress().length){
			case 4:
				System.out.println("根据byte数组长度判断这个IP地址是IPv4地址!");
				 break;
			case 16:
				System.out.println("根据byte数组长度判断这个IP地址是IPv6地址!");
				break;
		}
		
		if (address instanceof Inet4Address){
			System.out.println("使用instanceof判断这个IP地址是IPv4地址!");
		}
		if (address instanceof Inet6Address){
			System.out.println("使用instanceof判断这个IP地址是IPv6地址!");
		}
	}
}