SNMP4J Синглтон Реализация

Question

public class SNMPProxy implements Cloneable, Serializable
{

    Snmp snmp = null;

    /**
     * The transport mapping helps to use either UDP or TCP .
     */
    TransportMapping transport = null;

    /**
     * The snmp address of the robot.
     */
    String address = null;

    /**
     * Community of each device
     */
    private String community;

    /**
     * SNMP Version on each device
     */
    private int snmpVersion;

    //---------------------------------------------------------------------
    // Constructors.
    //---------------------------------------------------------------------
    /**
     * Constructor which takes in SNMP address of the device
     * @param address  SNMP Address of the bot
     */
    public SNMPProxy(String address, String community, int snmpVersion)
    {
        this.address = address;
        this.community = community;
        this.snmpVersion = snmpVersion;
    }

    /**
     * Empty Constructor
     */
    public SNMPProxy()
    {

    }

    //---------------------------------------------------------------------
    // SNMP Methods.
    //---------------------------------------------------------------------
    /**
     * Start the Snmp session. If you forget the listen() method you will not
     * get any data because the communication is asynchronous
     * and the listen() method listens for data.
     * If you are only using SNMPv2c( MPv2c()), you can make a cleaner
     * initialization that does not load cryptography related classes of v3
     * @throws IOException
     */
    public void start(MessageDispatcher disp) throws IOException

    {
        transport = new DefaultUdpTransportMapping();
        snmp = new Snmp(disp,transport);
        transport.listen();
    }

    /**
     * Close the SNMP connection which will close the socket connection and the Thread.
     */
    public void close() throws IOException
    {
        if (snmp != null)
        {
            snmp.close();
        }
        if (transport != null)
        {
            transport.close();
        }
    }

    /**
     * TODO pdu
     */
    public PDU getPDU(OID... oids)
    {
        PDU pdu = new PDU();
        pdu.setMaxRepetitions(512);
        pdu.setNonRepeaters(0);
        for (OID oid : oids)
        {
            pdu.add(new VariableBinding(oid));
        }
        pdu.setType(PDU.GET);
        return pdu;
    }

    /**
     * TODO ResponseEvent
     */
    public  ResponseEvent get(OID... oids) throws IOException
    {
        ResponseEvent response = snmp.send(getPDU(oids), getTarget(),null);

        if (response != null)
        {
            return response;
        }
        throw new RuntimeException("GET timed out");
    }

    /**
     * TODO
     */
    public int dataToInt(ResponseEvent evn, int n)
    {
        return evn.getResponse().get(n).getVariable().toInt();
    }

    /**
     * TODO
     */
    public String dataToString(ResponseEvent evn, int n)
    {
        return evn.getResponse().get(n).getVariable().toString();
    }

    /**
     * This method returns a Target, which contains information about
     * where the data should be fetched and how.
     * @return target
     */
    public  Target getTarget()

    {
        Address targetAddress = GenericAddress.parse(address);
        CommunityTarget target = new CommunityTarget();
        target.setCommunity(new OctetString(community));
        target.setAddress(targetAddress);
        target.setRetries(2);
        target.setTimeout(1500);
        target.setVersion(snmpVersion);
        return target;
    }

}

Я хочу создать экземпляр Singleton для SNMP. У меня есть несколько устройств, которые разговаривают с одним и тем же классом. Всякий раз, когда я говорю с этим классом, он создает экземпляр snmp и закрывает экземпляр после получения данных. Может ли кто-нибудь помочь мне с созданием одного экземпляра снаружи и вызывать один и тот же экземпляр каждый раз с любого устройства.