[SNMP4J] Writinf SNMP Manager using SNMP4J

[Tsiyona.Dershowitz at alcatel.co.il]

Hello,
 
I am writing a SNMP Manager that is supposed to do the following:
(1) Send snmp commands to snmp-agents, and handle their response.
(2) Receive snmp traps from snmp-agents.
 
I am using SNMP4J software package for writing the snmp manager.
 
I would like to use a SINGLE Snmp object (SNMP4J object) , both
for sending a snmp command and for receiving snmp traps.
 
So far, I have written two separate programs:
 
****************
*** Program 1:
****************
** The first program only listens for Snmp trap-PDUs.
** Its main code is as follows:
 
 // configure Snmp object
 UdpAddress address = new UdpAddress("127.0.0.1/1990");
 TransportMapping transport = new DefaultUdpTransportMapping(address);
 Snmp snmp = new Snmp(transport);
 transport.listen();
 
 // handle received traps here
 CommandResponder trapPrinter = new CommandResponder() {
  public synchronized void processPdu(CommandResponderEvent e) {
   PDU command = e.getPdu();
   if (command != null) {
    System.out.println(command.toString());
   }
  }
 };
 snmp.addCommandResponder(trapPrinter);
 
 
 
****************
*** Program 2:
****************
** The second program sends GET PDUs, and its main code is as follows:
 
 // configure Snmp object
 UdpAddress targetAddress = new UdpAddress("127.0.0.1/1985");
 CommunityTarget target = new CommunityTarget();
 target.setCommunity(new OctetString("public"));
 target.setAddress(targetAddress);
 target.setRetries(2);
 target.setTimeout(10000);
 target.setVersion(SnmpConstants.version1);
 Snmp snmp = new Snmp(new DefaultUdpTransportMapping());
 snmp.listen();
 
 // prepare the PDU for sending
 PDU command = new PDU();
 command.setType(PDU.GET);
 command.add(new VariableBinding(new OID("1.3.6.1.4.1.1331.11.5.1.0")));
 
 // now send the PDU
 ResponseEvent responseEvent = snmp.send(pdu, target);
 if (responseEvent != null)
 {
  // response has arrived. handle it
 }
 else
  System.out.println("null response received...");
 

*******************************************************************
 
I would like to unite these two programs into one, however, I cannot
seem to
properly allocate one Snmp object to handle both the sending and
receiving of PDUs.
 
I run two threads: thread-1 that does the listening for snmp traps,
and thread-2 which in charge of sending get/set PDUs.
 
I allocate the Snmp object in one place as follows:
 
 TransportMapping transport = new DefaultUdpTransportMapping(new
UdpAddress("127.0.0.1/1990"));
 Snmp snmp = new Snmp(transport);
 snmp.listen();
 
and I transfer it to both threads to be used there.
However, thread-2 sometimes fails to send PDUs using snmp.send(...);
 

What am I doing wrong? 
Can anyone guide me as for how I should allocate the Snmp object so
it is good for both sending PDUs, and for receiving traps?
 
Thanks,
Tsiyona