[SNMP4J] snmpTRAP

[abdel]

Hello, I have a small problem with function TRAP I am to go to see in the class snmpRequest but I am not able to find my problem here my code: 

import org.snmp4j.*;
import org.snmp4j.smi.*;
import org.snmp4j.util.*;
import org.snmp4j.event.*;
import org.snmp4j.transport.*;
import org.snmp4j.mp.*;
import org.snmp4j.security.*;
import org.apache.log4j.*;

public class snmpTrap {
    
    /** Creates a new instance of snmpTrap */
    public snmpTrap() 
    {
         int numDispatcherThreads = 2;
         try
        {
          Address targetAddress = GenericAddress.parse("udp:127.0.0.1/162");
                                     
          TransportMapping transport = new DefaultUdpTransportMapping();
                                
          CommandResponder trapPrinter = new CommandResponder() { 
          public synchronized void processPdu(CommandResponderEvent e) 
          {
            PDU command = e.getPDU();
            if (command != null) 
            {
               System.out.println(command.toString());
            }
          }
        };
        
          ThreadPool threadPool =
          ThreadPool.create("DispatcherPool", numDispatcherThreads);
          MessageDispatcher mtDispatcher =
          new MultiThreadedMessageDispatcher(threadPool, new MessageDispatcherImpl());
          mtDispatcher.addMessageProcessingModel(new MPv1());

          Snmp snmp = new Snmp(mtDispatcher, transport);
          snmp.addCommandResponder(trapPrinter);
          
          transport.listen();
          try {
                    this.wait();
              }
          catch (InterruptedException ex) {
              }    

      }
      catch(Exception ex)
      {
          ex.printStackTrace();
          System.out.println(ex.getMessage());
          System.exit(0);
      }
        
    }
}
but it posts me this error: 
java.lang.IllegalMonitorStateException: current thread not owner
        at java.lang.Object.wait(Native Method)
        at java.lang.Object.wait(Object.java:429)
        at snmpTrap.<init>(snmpTrap.java:47)
        at applic.main(applic.java:19)
log4j:WARN No appenders could be found for logger (org.snmp4j.transport.DefaultUdpTransportMapping).
log4j:WARN Please initialize the log4j system properly.