[SNMP4J] Basic test run question

[Tetsuro Motoyama]

I am new to the snmp4j and trying to test if I can run the simple program.

I took sample from SNMP class and created the following program that is
not working.  It compiles and runs with the outputs below.
Can anyone help me?

===================================================================
package Test;
import java.io.IOException;

import org.snmp4j.*;
import org.snmp4j.event.ResponseEvent;
import org.snmp4j.event.ResponseListener;
import org.snmp4j.mp.MPv3;
import org.snmp4j.mp.SnmpConstants;
import org.snmp4j.security.SecurityModels;
import org.snmp4j.security.SecurityProtocols;
import org.snmp4j.security.USM;
import org.snmp4j.smi.Address;
import org.snmp4j.smi.GenericAddress;
import org.snmp4j.smi.OID;
import org.snmp4j.smi.OctetString;
import org.snmp4j.smi.VariableBinding;
import org.snmp4j.transport.DefaultUdpTransportMapping;

public class TestClass {

	/**
	 * @param args
	 */
	@SuppressWarnings("deprecation")
	public static void main(String[] args) {
		Address targetAddress =
GenericAddress.parse("udp:172.30.4.51/161");
		TransportMapping transport = null;
		try {
			transport = new DefaultUdpTransportMapping();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		Snmp snmp = new Snmp(transport);

		
		   // setting up target
		   CommunityTarget target = new CommunityTarget();
		   target.setCommunity(new OctetString("public"));
		   target.setAddress(targetAddress);
		   target.setRetries(2);
		   target.setTimeout(100000);
		   target.setVersion(SnmpConstants.version1);
		   // creating PDU
		   PDU pdu = new PDU();
		   pdu.add(new VariableBinding(new OID(new int[]
{1,3,6,1,2,1,1})));
		   pdu.setType(PDU.GETNEXT);
		   // sending request
		   

		   ResponseEvent response = null;
		try {
			//response = snmp.send(pdu, target);
			response = snmp.getNext(pdu, target);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		Exception error = response.getError();
		 PDU responsePDU = response.getResponse();
		   // extract the address used by the agent to send the
response:
		   Address peerAddress = response.getPeerAddress();

		System.out.println("done: " + response);
		System.out.println("\nError is" + error);
		System.out.println("\n"+responsePDU);
		System.out.println("\n" + peerAddress);
	}
}
====================================================
Outputs are:
---------------------
done: org.snmp4j.event.ResponseEvent[source=org.snmp4j.Snmp at 192b996]

Error isnull

null

null