This class can catch the AUTH_PRIV v3 trap, also can catch the snmp v1, v2 and v3 normal trap. Contains SNMP4j v1 and v3 trap sender example.

MultiThreadedTrapReceiver

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package testsnmp4j;

import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.Vector;
import java.util.logging.Level;
import java.util.logging.Logger;

import org.snmp4j.*;
import org.snmp4j.mp.*;
import org.snmp4j.security.*;
import org.snmp4j.smi.*;
import org.snmp4j.transport.*;
import org.snmp4j.util.*;

/**
 *
 * @author kim_hu
 * 
 */
public class MultiThreadedTrapReceiver implements CommandResponder {

    private Address address = GenericAddress.parse("0.0.0.0/162");
    private int numDispatcherThreads = 2;
    private OID authProtocol = AuthMD5.ID;
    private OID privProtocol = PrivDES.ID;
    private OctetString securityName = new OctetString("MD5DES");
    private OctetString privPassphrase = new OctetString("MD5DESUserPrivPassword");
    private OctetString authPassphrase = new OctetString("MD5DESUserAuthPassword");

    public MultiThreadedTrapReceiver() {
        try {
            listen();
        } catch (IOException ex) {
            Logger.getLogger(MultiThreadedTrapReceiver.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
    
    public synchronized void listen() throws IOException {
        AbstractTransportMapping transport;
        if (address instanceof TcpAddress) {
            transport = new DefaultTcpTransportMapping((TcpAddress) address);
        } else {
            transport = new DefaultUdpTransportMapping((UdpAddress) address);
        }
        ThreadPool threadPool =
                ThreadPool.create("DispatcherPool", numDispatcherThreads);
        MessageDispatcher mtDispatcher =
                new MultiThreadedMessageDispatcher(threadPool, new MessageDispatcherImpl());

        // add message processing models
        mtDispatcher.addMessageProcessingModel(new MPv1());
        mtDispatcher.addMessageProcessingModel(new MPv2c());
        mtDispatcher.addMessageProcessingModel(new MPv3(new OctetString(MPv3.createLocalEngineID()).getValue()));

        // add all security protocols
        SecurityProtocols.getInstance().addDefaultProtocols();
        SecurityProtocols.getInstance().addPrivacyProtocol(new Priv3DES());

        Snmp snmp = new Snmp(mtDispatcher, transport);
        USM usm = new USM(SecurityProtocols.getInstance(), new OctetString(MPv3.createLocalEngineID()), 0);
        SecurityModels.getInstance().addSecurityModel(usm);
        // Add the configured user to the USM
        addUsmUser(snmp);

        snmp.addCommandResponder(this);

        transport.listen();

        try {
            this.wait();
        } catch (InterruptedException ex) {
            Thread.currentThread().interrupt();
        }
    }

    private void addUsmUser(Snmp snmp) {
        snmp.getUSM().addUser(securityName, new UsmUser(securityName,
                authProtocol,
                authPassphrase,
                privProtocol,
                privPassphrase));
    }

    @Override
    public void processPdu(CommandResponderEvent respEvnt) {
        System.out.println(respEvnt.getPDU());
        InetAddress pduAgentAddress = null;
        //System.out.println(respEvnt.getPDU() + " recieved;");
        //this.setPdu(respEvnt.getPDU());
        OctetString community = new OctetString(respEvnt.getSecurityName());
        System.out.println("community: " + community.toString());

        //handle the SNMP v1
        if (respEvnt.getPDU().getType() == PDU.V1TRAP) {
            Address address = respEvnt.getPeerAddress();
            String hostName = address.toString().split("/")[0];
            int nPort = Integer.parseInt(address.toString().split("/")[1]);
            try {
                pduAgentAddress = InetAddress.getByName(hostName);
            } catch (UnknownHostException ex) {
                Logger.getLogger(MultiThreadedTrapReceiver1.class.getName()).log(Level.SEVERE, null, ex);
            }
            System.out.println("hostname: " + pduAgentAddress.getHostAddress() + "; port: " + nPort);
        } else {
            Address address = respEvnt.getPeerAddress();
            String hostName = address.toString().split("/")[0];
            int nPort = Integer.parseInt(address.toString().split("/")[1]);
            try {
                pduAgentAddress = InetAddress.getByName(hostName);
            } catch (UnknownHostException ex) {
                Logger.getLogger(MultiThreadedTrapReceiver1.class.getName()).log(Level.SEVERE, null, ex);
            }
            System.out.println("hostname: " + pduAgentAddress.getHostAddress() + "; port: " + nPort);
        }
    }

    public static void main(String[] args) {
        MultiThreadedTrapReceiver trap = new MultiThreadedTrapReceiver();
    }
}

SnmpUtilSendTrapV1

/*
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 * and open the template in the editor.
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package testsnmp4j;

import java.io.IOException;

import org.snmp4j.*;
import org.snmp4j.mp.*;
import org.snmp4j.smi.*;
import org.snmp4j.transport.*;

/**
 *
 * @author kim_hu
 * SNMP4J v1 trap sender example
 * 
 */
public class SnmpUtilSendTrapV1 {

    private Snmp snmp = null;
    private Address targetAddress = null;

    public void initComm() throws IOException {
        targetAddress = GenericAddress.parse("udp:127.0.0.1/162");
        TransportMapping transport = new DefaultUdpTransportMapping();
        snmp = new Snmp(transport);
        transport.listen();
    }

    public void sendPDU() throws IOException {
        //Create Target 
        CommunityTarget comtarget = new CommunityTarget();
        comtarget.setVersion(SnmpConstants.version1);
        comtarget.setAddress(targetAddress);
        //comtarget.setRetries(2);
        comtarget.setTimeout(5000);
        comtarget.setSecurityName(new OctetString("public"));

        //Create PDU for V1
        PDUv1 pdu = new PDUv1();
        pdu.setType(PDU.V1TRAP);
        pdu.add(new VariableBinding(new OID("1.3.6.1.2.3377.10.1.1.1.1"),
                new OctetString("SnmpTrapv1")));
        pdu.add(new VariableBinding(new OID("1.3.6.1.2.3377.10.1.1.1.2"),
                new OctetString("JavaEE")));

        //Send the PDU
        snmp.send(pdu, comtarget);
    }
    
     public static void main(String[] args) {
        try {
            SnmpUtilSendTrapV1 util = new SnmpUtilSendTrapV1();
            util.initComm();
            util.sendPDU();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

SnmpUtilSendTrapV3

/*
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 * and open the template in the editor.
 */
package testsnmp4j;

import java.io.IOException;
import java.util.Vector;

import org.snmp4j.*;
import org.snmp4j.event.*;
import org.snmp4j.mp.*;
import org.snmp4j.security.*;
import org.snmp4j.smi.*;
import org.snmp4j.transport.*;

/**
 *
 * @author kim_hu
 * SNMP4j v3 trap sender example
 */
public class SnmpUtilSendTrapV3 {

    private Snmp snmp = null;
    private Address targetAddress = null;

    public void initComm() throws IOException {
        targetAddress = GenericAddress.parse("127.0.0.1/162");
        TransportMapping transport = new DefaultUdpTransportMapping();
        snmp = new Snmp(transport);
        snmp.listen();

    }

    /**
     * send trap
     *
     * @throws IOException
     */
    public void sendPDU() throws IOException {
        UserTarget target = new UserTarget();
        target.setAddress(targetAddress);
        target.setRetries(2);
        target.setTimeout(1500);
        // snmp version
        target.setVersion(SnmpConstants.version3);

        //target.setSecurityLevel(SecurityLevel.NOAUTH_NOPRIV);
        target.setSecurityLevel(SecurityLevel.AUTH_PRIV);
        target.setSecurityName(new OctetString("MD5DES"));

        USM usm = new USM(SecurityProtocols.getInstance(),
                new OctetString(MPv3.createLocalEngineID()), 0);
        usm.setEngineDiscoveryEnabled(true);
        SecurityModels.getInstance().addSecurityModel(usm);

        UsmUser user = new UsmUser(new OctetString("MD5DES"),
                AuthMD5.ID,
                new OctetString("MD5DESUserAuthPassword"),
                PrivDES.ID,
                new OctetString("MD5DESUserPrivPassword")); 
        snmp.getUSM().addUser(new OctetString("MD5DES"), user);

        // create PDU
        ScopedPDU pdu = new ScopedPDU();
        pdu.add(new VariableBinding(new OID("1.3.6.1.2.1.1.3.0"),
                new OctetString("SnmpTrapv3")));
        pdu.add(new VariableBinding(new OID("1.3.6.1.2.1.1.5.0"),
                new OctetString("JavaEE")));
        pdu.setType(PDU.TRAP);

        // send PDU to Agent and recieve Response
        ResponseEvent respEvnt = snmp.send(pdu, target);

        // analyze Response
        if (respEvnt != null && respEvnt.getResponse() != null) {
            Vector<VariableBinding> recVBs = (Vector<VariableBinding>) respEvnt.getResponse()
                    .getVariableBindings();
            for (int i = 0; i < recVBs.size(); i++) {
                VariableBinding recVB = recVBs.elementAt(i);
                System.out.println(recVB.getOid() + " : " + recVB.getVariable());
            }
        }
        snmp.close();
    }

    public static void main(String[] args) {
        try {
            SnmpUtilSendTrapV3 util = new SnmpUtilSendTrapV3();
            util.initComm();
            util.sendPDU();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

how to store trap from socket to in a queue before processing them by process pdu

good job

MultiThreadedTrapReceiver1

what is this class?

where is the process PDU for Trap v3 ?

This has been very helpful to me, thank you