import java.net.*;

public class NetTool {
    InetAddress myIPaddress = null;

    InetAddress myServer = null;

    public static void main(String args[]) {
        NetTool mytool;
        mytool = new NetTool();
        System.out.println("Your host IP is: " + mytool.getMyIP());
        System.out.println("The Server IP is :" + mytool.getServerIP());

    }

    // 取得LOCALHOST的IP地址

    public InetAddress getMyIP() {
        try {
            myIPaddress = InetAddress.getLocalHost();
        } catch (UnknownHostException e) {
        }
        return (myIPaddress);
    }

    // 取得 www.abc.com 的IP地址

    public InetAddress getServerIP() {
        try {
            myServer = InetAddress.getByName("www.abc.com");
        } catch (UnknownHostException e) {
        }
        return (myServer);
    }

}

呵呵
不错啊````````