SNMP4J adding user - snmp

Question

I've been doing some very basic SNMP4J programming. All I want to do is send a simple "get" request but so far my responses have been null. I opened up wireshark and found that in the under Simple Network Management Protocol, my msgUserName is blank and I need that to be populated.
I thought I had set it using the following code:
Snmp snmp = new Snmp(transport);
USM usm = new USM(SecurityProtocols.getInstance(), new OctetString(MPv3.createLocalEngineID()), 0);
SecurityModels.getInstance().addSecurityModel(usm);
transport.listen();
UsmUser user = new UsmUser(new OctetString("SNMPManager"), AuthSHA.ID,new OctetString("password"),null,null);
// add user to the USM
snmp.getUSM().addUser(user.getSecurityName(), user);
Am I going about it the wrong way? If not, how do I set the msgUserName as seen in my wireshark dump of the get-request? I'm very new to SNMP, so I'm essentially running off examples.

Answer 1

This is a working snmpset you can write snmp get same way.Snmp4j v2 and v3 not using same api classes.
private void snmpSetV3(VariableBinding[] bindings) throws TimeOutException, OperationFailed {
Snmp snmp = null;
try {
PDU pdu = new ScopedPDU();
USM usm = new USM(SecurityProtocols.getInstance(), new OctetString(MPv3.createLocalEngineID()), 0);
SecurityModels.getInstance().addSecurityModel(usm);
snmp = new Snmp(new DefaultUdpTransportMapping());
snmp.getUSM().addUser(new OctetString(Username), new UsmUser(new OctetString(Username), AuthMD5.ID, new OctetString(Password), AuthMD5.ID, null));
ScopedPDU scopedPDU = (ScopedPDU) pdu;
scopedPDU.setType(PDU.SET);
scopedPDU.addAll(bindings);
UserTarget target = new UserTarget();
target.setAddress(new UdpAddress(IPAddress + "/" + Port));
target.setVersion(version); //SnmpConstants.version3
target.setRetries(retries);
target.setTimeout(timeout);
target.setSecurityLevel(securityLevel); //SecurityLevel.AUTH_NOPRIV
target.setSecurityName(new OctetString(Username));
snmp.listen();
ResponseEvent response = snmp.send(pdu, target);
if (response.getResponse() != null) {
PDU responsePDU = response.getResponse();
if (responsePDU != null) {
if (responsePDU.getErrorStatus() == PDU.noError) {
return;
}
throw new OperationFailed("Error: Request Failed, "
+ "Error Status = " + responsePDU.getErrorStatus()
+ ", Error Index = " + responsePDU.getErrorIndex()
+ ", Error Status Text = " + responsePDU.getErrorStatusText());
}
}
throw new TimeOutException("Error: Agent Timeout... ");
} catch (IOException e) {
throw new OperationFailed(e.getMessage(), e);
} finally {
if (snmp != null) {
try {
snmp.close();
} catch (IOException ex) {
_logger.error(ex.getMessage(), ex);
}
}
}
}