JavaTest.java

import java.net.InetAddress;
import java.net.UnknownHostException;
import java.nio.ByteBuffer;

import fr.free.miniupnp.libnatpmp.NatPmp;
import fr.free.miniupnp.libnatpmp.NatPmpResponse;

class JavaTest {
 public static void main(String[] args) {
	NatPmp natpmp = new NatPmp();

 natpmp.sendPublicAddressRequest();
 NatPmpResponse response = new NatPmpResponse();

 int result = -1;
 do{
 result = natpmp.readNatPmpResponseOrRetry(response);
	 try {
		Thread.sleep(4000);
	 } catch (InterruptedException e) {
		//fallthrough
	 }
 } while (result != 0);

	byte[] bytes = intToByteArray(response.addr);

	try {
	 InetAddress inetAddress = InetAddress.getByAddress(bytes);
	 System.out.println("Public address is " + inetAddress);
	} catch (UnknownHostException e) {
	 throw new RuntimeException(e);
	}
 }

 public static final byte[] intToByteArray(int value) {
 return new byte[] {
 (byte)value,
 (byte)(value >>> 8),
 (byte)(value >>> 16),
 (byte)(value >>> 24)};
 }
}