The SNMP Proxy Implementation

public void initializeProxy(String h, int p,
                            String strOid, String name)
    throws UnknownHostException, SnmpStatusException {
	
    host = h;
    port = p;
    oid = strOid;
    mibName = name;
	
    // Initialization for SNMP v1 protocol.
    //
    SnmpParameters paramsV1 = new SnmpParameters("public", "private");
    paramsV1.setProtocolVersion(SnmpDefinitions.snmpVersionOne);
    SnmpPeer peerV1 = new SnmpPeer(host, port);
    peerV1.setSnmpParam(paramsV1);
    sessionV1 = new SnmpSession("SnmpMibAgentImpl session V1");
    sessionV1.setDefaultPeer(peerV1);

    // Using SNMP v1 protocol, errors are not fixed and
    // forwarded to the manager
    sessionV1.snmpOptions.setPduFixedOnError(false);

    // Initialization for SNMP v2 protocol.
    //
    SnmpParameters paramsV2 = new SnmpParameters("public", "private");
    paramsV2.setProtocolVersion(SnmpDefinitions.snmpVersionTwo);
    SnmpPeer peerV2 = new SnmpPeer(host, port);
    peerV2.setSnmpParam(paramsV2);
    // If we get an error, we don't retry the request using SNMP v2,
    // but we try the request using SNMP v1
    peerV2.setMaxRetries(0);
    sessionV2 = new SnmpSession("SnmpMibAgentImpl session V2");
    sessionV2.setDefaultPeer(peerV2);
    // Using SNMP v2 protocol, the error is fixed
    //
    sessionV2.snmpOptions.setPduFixedOnError(true);

    // Initialization for SNMP v2 protocol simulated
    // using SNMP v1 protocol
    //
    sessionV2WithV1 = new SnmpSession("SnmpMibAgentImpl session V2 with V1");
    sessionV2WithV1.setDefaultPeer(peerV1);
    // Simulating SNMP v2 with SNMP v1 protocol, the error is fixed.
    //
    sessionV2WithV1.snmpOptions.setPduFixedOnError(true);
}

// the exposed method
public void get(SnmpMibRequest inRequest) throws SnmpStatusException {
			  	  	  
    java.lang.System.out.println(
        "Proxy: Sending get request to SNMP sub-agent on " + 
            host + " using port " + port);

    // Get the protocol version
    final int version = inRequest.getVersion();

    // Request using SNMP v1 protocol
    if (version == SnmpDefinitions.snmpVersionOne) {
        get(inRequest, version, sessionV1);
    }

    // Request using SNMP v2 protocol.
    if (version == SnmpDefinitions.snmpVersionTwo) {
        get(inRequest, version, sessionV2);
    }
}

// the internal implementation
private void get(SnmpMibRequest inRequest, int version, SnmpSession session)
    throws SnmpStatusException {
	
    // Construction of the SnmpVarBindList for the request.
    final SnmpVarbindList varbindlist = 
        new SnmpVarbindList("SnmpMibAgentImpl varbind list",
                             inRequest.getSubList() );

    SnmpRequest request = null;
    try {
        request = session.snmpGet(null, varbindlist);
    } 
    catch (SnmpStatusException e) {
        throw new SnmpStatusException(SnmpDefinitions.snmpRspGenErr, 0);
    }
    java.lang.System.out.println("\nRequest:\n" + request.toString());
	
    boolean completed = request.waitForCompletion(10000);
    if (completed == false) {

        // If the completion failed using SNMP v1, we give up
        if (version == SnmpDefinitions.snmpVersionOne) {
            java.lang.System.out.println(
                "\nRequest timed out: check reachability of sub-agent.");
            return;
        }

        // If the completion failed using SNMP v2, we try again using v1

        if (version == SnmpDefinitions.snmpVersionTwo) {
            get(inRequest, SnmpDefinitions.snmpVersionOne, sessionV2WithV1);
            return;
        }
    }

    // Check the request result
    int errorStatus = request.getErrorStatus();
    int errorIndex = request.getErrorIndex() + 1;
    if (errorStatus != SnmpDefinitions.snmpRspNoError) {

        // If there is an error status using v1, we throw an exception
        if (version == SnmpDefinitions.snmpVersionOne) {
            throw new SnmpStatusException(errorStatus, errorIndex);
        }
        // If there is an error status using v2, we try again using v1
        if (version == SnmpDefinitions.snmpVersionTwo) {
            get(inRequest, SnmpDefinitions.snmpVersionOne, sessionV2WithV1);
            return;
        }
    }
    // Get and display the returned values
    final SnmpVarbindList result = request.getResponseVarBindList();
    java.lang.System.out.println("\nResult: \n" + 
                                 result.varBindListToString());

    // Update the list parameter with the result
    // The varbinds in the result list are expected to be in the same
    // order as in the request, so we can safely loop sequentially
    // over both lists.
    Enumeration l = list.elements();
    for (Enumeration e = result.elements(); e.hasMoreElements();) {
        SnmpVarBind varres = (SnmpVarBind) e.nextElement();
        SnmpVarBind varbind = (SnmpVarBind) l.nextElement();
        varbind.value = varres.value;
    }
}