java.net包中的InetAddress类是与IP地址相关的类，利用该类可以获取IP地址、主机地址等信息。

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

public class Address {
    public static void main(String[] args) {
        InetAddress ip;
        try {
            ip = InetAddress.getLocalHost();
            String localname = ip.getHostName();
            String localip = ip.getHostAddress();
            System.out.println("本机名/本机IP地址：" + ip);
            System.out.println("本机名：" + localname);
            System.out.println("本机IP地址：" + localip);
        } catch (UnknownHostException e) {
            e.printStackTrace();
        }
    }
}

Java网络通信