一般情况直接输出的是127.0.0.1

import java.net.Inet4Address;
import java.net.Inet6Address;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.util.Enumeration;

public class Util {
public static void main(String[] a) throws UnknownHostException, SocketException{
	InetAddress inet = getFirstNonLoopbackAddress(true,false);
	System.out.println("local realIP: " + getIp());
	
}
public static String getIp(){
	try {
		return getFirstNonLoopbackAddress(true,false).getHostName() + "/" + getFirstNonLoopbackAddress(true,false).getHostAddress();
	} catch (SocketException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	}
	return " noIP!! ";
}

public static InetAddress getFirstNonLoopbackAddress(boolean preferIpv4, boolean preferIPv6) throws SocketException {
    Enumeration en = NetworkInterface.getNetworkInterfaces();
    while (en.hasMoreElements()) {
        NetworkInterface i = (NetworkInterface) en.nextElement();
        for (Enumeration en2 = i.getInetAddresses(); en2.hasMoreElements();) {
            InetAddress addr = (InetAddress) en2.nextElement();
            if (!addr.isLoopbackAddress()) {
                if (addr instanceof Inet4Address) {
                    if (preferIPv6) {
                        continue;
                    }
                    return addr;
                }
                if (addr instanceof Inet6Address) {
                    if (preferIpv4) {
                        continue;
                    }
                    return addr;
                }
            }
        }
    }
    return null;
}

}