Package org.snmp4j

Class Snmp

java.lang.Object
org.snmp4j.Snmp
All Implemented Interfaces:
EventListener, CommandResponder, Session
public class Snmp extends Object implements Session, CommandResponder
The Snmp class is the core of SNMP4J. It provides functions to send and receive SNMP PDUs. All SNMP PDU types can be send. Confirmed PDUs can be sent synchronously and asynchronously.

The Snmp class is transport protocol independent. Support for a specific TransportMapping instance is added by calling the addTransportMapping(TransportMapping transportMapping) method or creating a Snmp instance by using the non-default constructor with the corresponding transport mapping. Transport mappings are used for incoming and outgoing messages.

To setup a default SNMP session for UDP transport and with SNMPv3 support the following code snippet can be used:

   Address targetAddress = GenericAddress.parse("udp:127.0.0.1/161");
   TransportMapping transport = new DefaultUdpTransportMapping();
   snmp = new Snmp(transport);
   USM usm = new USM(SecurityProtocols.getInstance(),
                     new OctetString(MPv3.createLocalEngineID()), 0);
   SecurityModels.getInstance().addSecurityModel(usm);
   transport.listen();

How a synchronous SNMPv3 message with authentication and privacy is then sent illustrates the following code snippet: 

   // add user to the USM
   snmp.getUSM().addUser(new OctetString("MD5DES"),
                         new UsmUser(new OctetString("MD5DES"),
                                     AuthMD5.ID,
                                     new OctetString("MD5DESUserAuthPassword"),
                                     PrivDES.ID,
                                     new OctetString("MD5DESUserPrivPassword")));
   // create the target
   UserTarget target = new UserTarget();
   target.setAddress(targetAddress);
   target.setRetries(1);
   target.setTimeout(5000);
   target.setVersion(SnmpConstants.version3);
   target.setSecurityLevel(SecurityLevel.AUTH_PRIV);
   target.setSecurityName(new OctetString("MD5DES"));

   // create the PDU
   PDU pdu = new ScopedPDU();
   pdu.add(new VariableBinding(new OID("1.3.6")));
   pdu.setType(PDU.GETNEXT);

   // send the PDU
   ResponseEvent response = snmp.send(pdu, target);
   // extract the response PDU (could be null if timed out)
   PDU responsePDU = response.getResponse();
   // extract the address used by the agent to send the response:
   Address peerAddress = response.getPeerAddress();

An asynchronous SNMPv1 request is sent by the following code: 

   // setting up target
   CommunityTarget target = new CommunityTarget();
   target.setCommunity(new OctetString("public"));
   target.setAddress(targetAddress);
   target.setRetries(2);
   target.setTimeout(1500);
   target.setVersion(SnmpConstants.version1);
   // creating PDU
   PDU pdu = new PDU();
   pdu.add(new VariableBinding(new OID(new int[] {1,3,6,1,2,1,1,1})));
   pdu.add(new VariableBinding(new OID(new int[] {1,3,6,1,2,1,1,2})));
   pdu.setType(PDU.GETNEXT);
   // sending request
   ResponseListener listener = new ResponseListener() {
     public void onResponse(ResponseEvent event) {
       // Always cancel async request when response has been received
       // otherwise a memory leak is created! Not canceling a request
       // immediately can be useful when sending a request to a broadcast
       // address.
       ((Snmp)event.getSource()).cancel(event.getRequest(), this);
       System.out.println("Received response PDU is: "+event.getResponse());
     }
   };
   snmp.sendPDU(pdu, target, null, listener);

Traps (notifications) and other SNMP PDUs can be received by adding the following code to the first code snippet above: 

   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);
Version:
1.10
Author:
Frank Fock

  • Constructor Details

    • Snmp

      public Snmp()
      Creates a Snmp instance that uses a MessageDispatcherImpl with no message processing models and no security protols (by default). You will have to add those by calling the appropriate methods on getMessageDispatcher().

      At least one transport mapping has to be added before listen() is called in order to be able to send and receive SNMP messages.

      To initialize a Snmp instance created with this constructor follow this sample code: 

       Transport transport = ...;
 Snmp snmp = new Snmp();
 SecurityProtocols.getInstance().addDefaultProtocols();
 MessageDispatcher disp = snmp.getMessageDispatcher();
 disp.addMessageProcessingModel(new MPv1());
 disp.addMessageProcessingModel(new MPv2c());
 snmp.addTransportMapping(transport);
 OctetString localEngineID = new OctetString(
    MPv3.createLocalEngineID());
    // For command generators, you may use the following code to avoid
    // engine ID clashes:
    // MPv3.createLocalEngineID(
    //   new OctetString("MyUniqueID"+System.currentTimeMillis())));
 USM usm = new USM(SecurityProtocols.getInstance(), localEngineID, 0);
 disp.addMessageProcessingModel(new MPv3(usm));
 snmp.listen();

    • Snmp

      public Snmp(TransportMapping<? extends Address> transportMapping)
      Creates a Snmp instance that uses a MessageDispatcherImpl with all supported message processing models and the default security protols for dispatching.

      To initialize a Snmp instance created with this constructor follow this sample code: 

       Transport transport = ...;
 Snmp snmp = new Snmp(transport);
 OctetString localEngineID =
   new OctetString(snmp.getMPv3().getLocalEngineID());
 USM usm = new USM(SecurityProtocols.getInstance(), localEngineID, 0);
 SecurityModels.getInstance().addSecurityModel(usm);
 snmp.listen();
      Parameters:
      transportMapping - TransportMapping the initial TransportMapping. You can add more or remove the same later.

    • Snmp

      public Snmp(MessageDispatcher messageDispatcher, TransportMapping<? extends Address> transportMapping)
      Creates a Snmp instance by supplying a MessageDispatcher and a TransportMapping.

      As of version 1.1, the supplied message dispatcher is not altered in terms of adding any message processing models to it. This has to be done now outside the Snmp class.

      To initialize a Snmp instance created with this constructor follow this sample code: 

       Transport transport = ...;
 SecurityProtocols.getInstance().addDefaultProtocols();
 MessageDispatcher disp = new MessageDispatcherImpl();
 disp.addMessageProcessingModel(new MPv1());
 disp.addMessageProcessingModel(new MPv2c());
 Snmp snmp = new Snmp(disp, transport);
 OctetString localEngineID = new OctetString(
    MPv3.createLocalEngineID());
    // For command generators, you may use the following code to avoid
    // engine ID clashes:
    // MPv3.createLocalEngineID(
    //   new OctetString("MyUniqueID"+System.currentTimeMillis())));
 USM usm = new USM(SecurityProtocols.getInstance(), localEngineID, 0);
 disp.addMessageProcessingModel(new MPv3(usm));
 snmp.listen();
      Parameters:
      messageDispatcher - a MessageDispatcher instance that will be used to dispatch incoming and outgoing messages.
      transportMapping - the initial TransportMapping, which may be null. You can add or remove transport mappings later using addTransportMapping(org.snmp4j.TransportMapping<? extends org.snmp4j.smi.Address>) and removeTransportMapping(org.snmp4j.TransportMapping<? extends org.snmp4j.smi.Address>) respectively.

    • Snmp

      public Snmp(MessageDispatcher messageDispatcher)
      Creates a Snmp instance by supplying a MessageDispatcher.

      The supplied message dispatcher is not altered in terms of adding any message processing models to it. This has to be done now outside the Snmp class.

      Do not forget to add at least one transport mapping before calling the listen method!

      To initialize a Snmp instance created with this constructor follow this sample code: 

       Transport transport = ...;
 SecurityProtocols.getInstance().addDefaultProtocols();
 MessageDispatcher disp = new MessageDispatcherImpl();
 disp.addMessageProcessingModel(new MPv1());
 disp.addMessageProcessingModel(new MPv2c());
 Snmp snmp = new Snmp(disp);
 snmp.addTransportMapping(transport);
 OctetString localEngineID = new OctetString(
    MPv3.createLocalEngineID());
    // For command generators, you may use the following code to avoid
    // engine ID clashes:
    // MPv3.createLocalEngineID(
    //   new OctetString("MyUniqueID"+System.currentTimeMillis())));
 USM usm = new USM(SecurityProtocols.getInstance(), localEngineID, 0);
 disp.addMessageProcessingModel(new MPv3(usm));
 snmp.listen();
      Parameters:
      messageDispatcher - a MessageDispatcher instance that will be used to dispatch incoming and outgoing messages.
      Since:
      1.5

  • Method Details

    • initMessageDispatcher

      protected final void initMessageDispatcher()

    • getMessageDispatcher

      public MessageDispatcher getMessageDispatcher()
      Returns the message dispatcher associated with this SNMP session.
      Returns:
      a MessageDispatcher instance.
      Since:
      1.1

    • setMessageDispatcher

      public void setMessageDispatcher(MessageDispatcher messageDispatcher)
      Sets the message dispatcher associated with this SNMP session. The CommandResponder registration is removed from the existing message dispatcher (if not null).
      Parameters:
      messageDispatcher - a message dispatcher that processes incoming SNMP PDUs.
      Since:
      2.5.7

    • addTransportMapping

      public void addTransportMapping(TransportMapping<? extends Address> transportMapping)
      Adds a TransportMapping to this SNMP session.
      Parameters:
      transportMapping - a TransportMapping instance.

    • removeTransportMapping

      public void removeTransportMapping(TransportMapping<? extends Address> transportMapping)
      Removes the specified transport mapping from this SNMP session. If the transport mapping is not currently part of this SNMP session, this method will have no effect.
      Parameters:
      transportMapping - a previously added TransportMapping.

    • addNotificationListener

      public boolean addNotificationListener(TransportMapping transportMapping, Address listenAddress, CommandResponder listener)
      Adds a notification listener to this Snmp instance. Calling this method will create a transport mapping for the specified listening address and registers the provided CommandResponder with the internal NotificationDispatcher.
      Parameters:
      transportMapping - the TransportMapping that is listening on the provided listenAddress. Call TransportMappings.getInstance().createTransportMapping(listenAddress); to create such a transport mapping.
      listenAddress - the Address denoting the transport end-point (interface and port) to listen for incoming notifications.
      listener - the CommandResponder instance that should handle the received notifications.
      Returns:
      true if registration was successful and false if, for example, the transport mapping for the listen address could not be created.
      Since:
      2.5.0

    • addNotificationListener

      public boolean addNotificationListener(Address listenAddress, CommandResponder listener)
      Adds a notification listener to this Snmp instance. Calling this method will create a transport mapping for the specified listening address and registers the provided CommandResponder with the internal NotificationDispatcher.
      Parameters:
      listenAddress - the Address denoting the transport end-point (interface and port) to listen for incoming notifications.
      listener - the CommandResponder instance that should handle the received notifications.
      Returns:
      true if registration was successful and false if, for example, the transport mapping for the listen address could not be created.
      Since:
      1.6

    • removeNotificationListener

      public boolean removeNotificationListener(Address listenAddress)
      Removes (deletes) the notification listener for the specified transport endpoint.
      Parameters:
      listenAddress - the listen Address to be removed.
      Returns:
      true if the notification listener has been removed successfully.

    • getNotificationListenerTM

      public TransportMapping getNotificationListenerTM(Address listenAddress)
      Gets the transport mapping registered for the specified listen address.
      Parameters:
      listenAddress - the listen address.
      Returns:
      the TransportMapping for the specified listen address or null if there is no notification listener for that address.
      Since:
      2.5.0

    • listen

      public void listen() throws IOException
      Puts all associated transport mappings into listen mode.
      Throws:
      IOException - if a transport mapping throws an IOException when its TransportMapping.listen() method has been called.

    • getNextRequestID

      public int getNextRequestID()
      Gets the next unique request ID. The returned ID is unique across the last 2^31-1 IDs generated by this message dispatcher.
      Returns:
      an integer value in the range 1..2^31-1. The returned ID can be used to map responses to requests send through this message dispatcher.
      Since:
      1.1
      See Also:

    • close

      public void close() throws IOException
      Closes the session and frees any allocated resources, i.e. sockets and the internal thread for processing request timeouts.

      If there are any pending requests, the ResponseListener associated with the pending requests, will be called with a null response and a InterruptedException in the error member of the ResponseEvent returned.

      After a Session has been closed it must not be used anymore.

      Specified by:
      close in interface Session
      Throws:
      IOException - if a transport mapping cannot be closed successfully.

    • get

      public ResponseEvent get(PDU pdu, Target target) throws IOException
      Sends a GET request to a target. This method sets the PDU's type to PDU.GET and then sends a synchronous request to the supplied target.
      Parameters:
      pdu - a PDU instance. For SNMPv3 messages, the supplied PDU instance has to be a ScopedPDU instance.
      target - the Target instance representing the target SNMP engine where to send the pdu.
      Returns:
      the received response encapsulated in a ResponseEvent instance. To obtain the received response PDU call ResponseEvent.getResponse(). If the request timed out, that method will return null.
      Throws:
      IOException - if the PDU cannot be sent to the target.
      Since:
      1.1

    • get

      public void get(PDU pdu, Target target, Object userHandle, ResponseListener listener) throws IOException
      Asynchronously sends a GET request PDU to the given target. The response is then returned by calling the supplied ResponseListener instance.
      Parameters:
      pdu - the PDU instance to send.
      target - the Target instance representing the target SNMP engine where to send the pdu.
      userHandle - an user defined handle that is returned when the request is returned via the listener object.
      listener - a ResponseListener instance that is called when pdu is a confirmed PDU and the request is either answered or timed out.
      Throws:
      IOException - if the PDU cannot be sent to the target.
      Since:
      1.1

    • getNext

      public ResponseEvent getNext(PDU pdu, Target target) throws IOException
      Sends a GETNEXT request to a target. This method sets the PDU's type to PDU.GETNEXT and then sends a synchronous request to the supplied target. This method is a convenience wrapper for the send(PDU pdu, Target target) method.
      Parameters:
      pdu - a PDU instance. For SNMPv3 messages, the supplied PDU instance has to be a ScopedPDU instance.
      target - the Target instance representing the target SNMP engine where to send the pdu.
      Returns:
      the received response encapsulated in a ResponseEvent instance. To obtain the received response PDU call ResponseEvent.getResponse(). If the request timed out, that method will return null.
      Throws:
      IOException - if the PDU cannot be sent to the target.
      Since:
      1.1

    • getNext

      public void getNext(PDU pdu, Target target, Object userHandle, ResponseListener listener) throws IOException
      Asynchronously sends a GETNEXT request PDU to the given target. The response is then returned by calling the supplied ResponseListener instance.
      Parameters:
      pdu - the PDU instance to send.
      target - the Target instance representing the target SNMP engine where to send the pdu.
      userHandle - an user defined handle that is returned when the request is returned via the listener object.
      listener - a ResponseListener instance that is called when pdu is a confirmed PDU and the request is either answered or timed out.
      Throws:
      IOException - if the PDU cannot be sent to the target.
      Since:
      1.1

    • getBulk

      public ResponseEvent getBulk(PDU pdu, Target target) throws IOException
      Sends a GETBULK request to a target. This method sets the PDU's type to PDU.GETBULK and then sends a synchronous request to the supplied target. This method is a convenience wrapper for the send(PDU pdu, Target target) method.
      Parameters:
      pdu - a PDU instance. For SNMPv3 messages, the supplied PDU instance has to be a ScopedPDU instance.
      target - the Target instance representing the target SNMP engine where to send the pdu.
      Returns:
      the received response encapsulated in a ResponseEvent instance. To obtain the received response PDU call ResponseEvent.getResponse(). If the request timed out, that method will return null.
      Throws:
      IOException - if the PDU cannot be sent to the target.
      Since:
      1.1

    • getBulk

      public void getBulk(PDU pdu, Target target, Object userHandle, ResponseListener listener) throws IOException
      Asynchronously sends a GETBULK request PDU to the given target. The response is then returned by calling the supplied ResponseListener instance.
      Parameters:
      pdu - the PDU instance to send.
      target - the Target instance representing the target SNMP engine where to send the pdu.
      userHandle - an user defined handle that is returned when the request is returned via the listener object.
      listener - a ResponseListener instance that is called when pdu is a confirmed PDU and the request is either answered or timed out.
      Throws:
      IOException - if the PDU cannot be sent to the target.
      Since:
      1.1

    • inform

      public ResponseEvent inform(PDU pdu, Target target) throws IOException
      Sends an INFORM request to a target. This method sets the PDU's type to PDU.INFORM and then sends a synchronous request to the supplied target. This method is a convenience wrapper for the send(PDU pdu, Target target) method.
      Parameters:
      pdu - a PDU instance. For SNMPv3 messages, the supplied PDU instance has to be a ScopedPDU instance.
      target - the Target instance representing the target SNMP engine where to send the pdu.
      Returns:
      the received response encapsulated in a ResponseEvent instance. To obtain the received response PDU call ResponseEvent.getResponse(). If the request timed out, that method will return null.
      Throws:
      IOException - if the inform request could not be send to the specified target.
      Since:
      1.1

    • inform

      public void inform(PDU pdu, Target target, Object userHandle, ResponseListener listener) throws IOException
      Asynchronously sends an INFORM request PDU to the given target. The response is then returned by calling the supplied ResponseListener instance.
      Parameters:
      pdu - the PDU instance to send.
      target - the Target instance representing the target SNMP engine where to send the pdu.
      userHandle - an user defined handle that is returned when the request is returned via the listener object.
      listener - a ResponseListener instance that is called when pdu is a confirmed PDU and the request is either answered or timed out.
      Throws:
      IOException - if the PDU cannot be sent to the target.
      Since:
      1.1

    • trap

      public void trap(PDUv1 pdu, Target target) throws IOException
      Sends a SNMPv1 trap to a target. This method sets the PDU's type to PDU.V1TRAP and then sends it to the supplied target. This method is a convenience wrapper for the send(PDU pdu, Target target) method.
      Parameters:
      pdu - a PDUv1 instance.
      target - the Target instance representing the target SNMP engine where to send the pdu. The selected SNMP protocol version for the target must be SnmpConstants.version1.
      Throws:
      IOException - if the trap cannot be sent.
      Since:
      1.1

    • notify

      public void notify(PDU pdu, Target target) throws IOException
      Sends a SNMPv2c or SNMPv3 notification to a target. This method sets the PDU's type to PDU.NOTIFICATION and then sends it to the supplied target. This method is a convenience wrapper for the send(PDU pdu, Target target) method.
      Parameters:
      pdu - a PDUv1 instance.
      target - the Target instance representing the target SNMP engine where to send the pdu. The selected SNMP protocol version for the target must be SnmpConstants.version2c or SnmpConstants.version2c.
      Throws:
      IOException - if the notification cannot be sent.
      Since:
      1.1

    • set

      public ResponseEvent set(PDU pdu, Target target) throws IOException
      Sends a SET request to a target. This method sets the PDU's type to PDU.SET and then sends a synchronous request to the supplied target.
      Parameters:
      pdu - a PDU instance. For SNMPv3 messages, the supplied PDU instance has to be a ScopedPDU instance.
      target - the Target instance representing the target SNMP engine where to send the pdu.
      Returns:
      the received response encapsulated in a ResponseEvent instance. To obtain the received response PDU call ResponseEvent.getResponse(). If the request timed out, that method will return null.
      Throws:
      IOException - if the PDU cannot be sent to the target.
      Since:
      1.1

    • set

      public void set(PDU pdu, Target target, Object userHandle, ResponseListener listener) throws IOException
      Asynchronously sends a SET request PDU to the given target. The response is then returned by calling the supplied ResponseListener instance.
      Parameters:
      pdu - the PDU instance to send.
      target - the Target instance representing the target SNMP engine where to send the pdu.
      userHandle - an user defined handle that is returned when the request is returned via the listener object.
      listener - a ResponseListener instance that is called when pdu is a confirmed PDU and the request is either answered or timed out.
      Throws:
      IOException - if the PDU cannot be sent to the target.
      Since:
      1.1

    • send

      public ResponseEvent send(PDU pdu, Target target) throws IOException
      Description copied from interface: Session
      Sends a PDU to the given target and returns the received response PDU.
      Specified by:
      send in interface Session
      Parameters:
      pdu - the PDU to send.
      target - the Target instance that specifies how and where to send the PDU.
      Returns:
      the received response encapsulated in a ResponseEvent instance. To obtain the received response PDU call ResponseEvent.getResponse(). If the request timed out, that method will return null. If the sent pdu is an unconfirmed PDU (notification, response, or report), then null will be returned.
      Throws:
      IOException - if the message could not be send.

    • send

      public ResponseEvent send(PDU pdu, Target target, TransportMapping transport) throws IOException
      Sends a PDU to the given target and if the PDU is a confirmed request, then the received response is returned synchronously.
      Specified by:
      send in interface Session
      Parameters:
      pdu - a PDU instance. When sending a SNMPv1 trap PDU, the supplied PDU instance must be a PDUv1. For all types of SNMPv3 messages, the supplied PDU instance has to be a ScopedPDU instance.
      target - the Target instance representing the target SNMP engine where to send the pdu.
      transport - specifies the TransportMapping to be used when sending the PDU. If transport is null, the associated message dispatcher will try to determine the transport mapping by the target's address.
      Returns:
      the received response encapsulated in a ResponseEvent instance. To obtain the received response PDU call ResponseEvent.getResponse(). If the request timed out, that method will return null. If the sent pdu is an unconfirmed PDU (notification, response, or report), then null will be returned.
      Throws:
      IOException - if the message could not be sent.
      See Also:

    • send

      public void send(PDU pdu, Target target, Object userHandle, ResponseListener listener) throws IOException
      Description copied from interface: Session
      Asynchronously sends a PDU to the given target. The response is then returned by calling the supplied ResponseListener instance.
      Specified by:
      send in interface Session
      Parameters:
      pdu - the PDU instance to send.
      target - the Target instance representing the target SNMP engine where to send the pdu.
      userHandle - an user defined handle that is returned when the request is returned via the listener object.
      listener - a ResponseListener instance that is called when pdu is a confirmed PDU and the request is either answered or timed out.
      Throws:
      IOException - if the message could not be send.

    • send

      public void send(PDU pdu, Target target, TransportMapping transport, Object userHandle, ResponseListener listener) throws IOException
      Description copied from interface: Session
      Asynchronously sends a PDU to the given target. The response is then returned by calling the supplied ResponseListener instance.
      Specified by:
      send in interface Session
      Parameters:
      pdu - the PDU instance to send.
      target - the Target instance representing the target SNMP engine where to send the pdu.
      transport - specifies the TransportMapping to be used when sending the PDU. If transport is null, the associated message dispatcher will try to determine the transport mapping by the target's address.
      userHandle - an user defined handle that is returned when the request is returned via the listener object.
      listener - a ResponseListener instance that is called when pdu is a confirmed PDU and the request is either answered or timed out.
      Throws:
      IOException - if the message could not be send.

    • sendMessage

      protected PduHandle sendMessage(PDU pdu, Target target, TransportMapping transport, PduHandleCallback<PDU> pduHandleCallback) throws IOException
      Actually sends a PDU to a target and returns a handle for the sent PDU.
      Parameters:
      pdu - the PDU instance to be sent.
      target - a Target instance denoting the target SNMP entity.
      transport - the (optional) transport mapping to be used to send the request. If transport is null a suitable transport mapping is determined from the target address.
      pduHandleCallback - callback for newly created PDU handles before the request is sent out.
      Returns:
      PduHandle that uniquely identifies the sent PDU for further reference.
      Throws:
      IOException - if the transport fails to send the PDU or the if the message cannot be BER encoded.

    • lookupTransportMapping

      protected TransportMapping lookupTransportMapping(Target target)

    • cancel

      public void cancel(PDU request, ResponseListener listener)
      Description copied from interface: Session
      Cancels an asynchronous request. Any asynchronous request must be canceled when the supplied response listener is being called, even if the ResponseEvent indicates an error.
      Specified by:
      cancel in interface Session
      Parameters:
      request - a request PDU as sent via Session.send(PDU pdu, Target target, Object userHandle, ResponseListener listener) or any .
      listener - a ResponseListener instance.

    • setLocalEngine

      public void setLocalEngine(byte[] engineID, int engineBoots, int engineTime)
      Sets the local engine ID for the SNMP entity represented by this Snmp instance. This is a convenience method that sets the local engine ID in the associated MPv3 and USM.
      Parameters:
      engineID - a byte array containing the local engine ID. The length and content has to comply with the constraints defined in the SNMP-FRAMEWORK-MIB.
      engineBoots - the number of boots of this SNMP engine (zero based).
      engineTime - the number of seconds since the value of engineBoots last changed.
      See Also:

    • getLocalEngineID

      public byte[] getLocalEngineID()
      Gets the local engine ID if the MPv3 is available, otherwise a runtime exception is thrown.
      Returns:
      byte[] the local engine ID.

    • discoverAuthoritativeEngineID

      public byte[] discoverAuthoritativeEngineID(Address address, long timeout)
      Discovers the engine ID of the SNMPv3 entity denoted by the supplied address. This method does not need to be called for normal operation, because SNMP4J automatically discovers authoritative engine IDs and also automatically synchronize engine time values.

      For this method to operate successfully, the discover engine IDs flag in USM must be true (which is the default).

      Parameters:
      address - an Address instance representing the transport address of the SNMPv3 entity for which its authoritative engine ID should be discovered.
      timeout - the maximum time in milliseconds to wait for a response.
      Returns:
      a byte array containing the authoritative engine ID or null if it could not be discovered.
      See Also:

    • getUSM

      public USM getUSM()
      Gets the User Based Security Model (USM). This is a convenience method that uses the MPv3.getSecurityModel(int) method of the associated MPv3 instance to get the USM.
      Returns:
      the USM instance associated with the MPv3 bound to this Snmp instance, or null otherwise.

    • getMessageProcessingModel

      public MessageProcessingModel getMessageProcessingModel(int messageProcessingModel)
      Gets the message processing model for the supplied ID.
      Parameters:
      messageProcessingModel - a mesage processing model ID as defined in MessageProcessingModel.
      Returns:
      MessageProcessingModel a MessageProcessingModel if messageProcessingModel has been registered with the message dispatcher associated with this SNMP session.

    • processPdu

      public void processPdu(CommandResponderEvent event)
      Process an incoming request or notification PDU.
      Specified by:
      processPdu in interface CommandResponder
      Parameters:
      event - a CommandResponderEvent with the decoded incoming PDU as dispatched to this method call by the associated message dispatcher.

    • isContextEngineIdDiscoveryDisabled

      public boolean isContextEngineIdDiscoveryDisabled()
      Checks whether RFC5343 based context engine ID discovery is disabled or not. The default value is false.
      Returns:
      true if context engine ID discovery is disabled.
      Since:
      2.0

    • setContextEngineIdDiscoveryDisabled

      public void setContextEngineIdDiscoveryDisabled(boolean contextEngineIdDiscoveryDisabled)
      Sets the RFC5343 based context engine ID discovery. The default value is false.
      Parameters:
      contextEngineIdDiscoveryDisabled - true to disable context engine ID discovery, false to enable context engine ID discovery.
      Since:
      2.0

    • getCachedContextEngineId

      public OctetString getCachedContextEngineId(Address targetAddress)
      Get a cached RFC 5343 context engine ID for the specified address.
      Parameters:
      targetAddress - the target address that returned the context engine ID.
      Returns:
      the cached context engine ID retrieved by RFC 5343 discovery or null if no such ID had been cached yet or the cached value was already removed either explicitly with removeCachedContextEngineId(Address) or implicitly because the address object was no longer associated with any open connection (i.e., the internally WeakHashMap recognized no more active references on the address key).
      Since:
      2.8.10

    • removeCachedContextEngineId

      public OctetString removeCachedContextEngineId(Address target)
      Remove a cached RFC 5343 context engine ID for the specified address and return it. To remove all cached IDs, call setContextEngineIdDiscoveryDisabled(boolean) with true.
      Parameters:
      target - the target address that returned the context engine ID.
      Returns:
      the removed cached context engine ID retrieved by RFC 5343 discovery or null if no such ID had been cached yet.
      Since:
      2.8.10

    • resendRequest

      protected boolean resendRequest(org.snmp4j.Snmp.PendingRequest request, PDU response)

    • handleInternalResponse

      protected void handleInternalResponse(PDU response, PDU pdu, Address target)

    • removeCommandResponder

      public void removeCommandResponder(CommandResponder listener)
      Removes a CommandResponder from this SNMP session.
      Parameters:
      listener - a previously added CommandResponder instance.

    • addCommandResponder

      public void addCommandResponder(CommandResponder listener)
      Adds a CommandResponder to this SNMP session. The command responder will then be informed about incoming SNMP PDUs of any kind that are not related to any outstanding requests of this SNMP session.
      Parameters:
      listener - the CommandResponder instance to be added.

    • fireProcessPdu

      protected void fireProcessPdu(CommandResponderEvent event)
      Fires a CommandResponderEvent event to inform listeners about a received PDU. If a listener has marked the event as processed further listeners will not be informed about the event.
      Parameters:
      event - a CommandResponderEvent.

    • getTimeoutModel

      public TimeoutModel getTimeoutModel()
      Gets the timeout model associated with this SNMP session.
      Returns:
      a TimeoutModel instance (never null).
      See Also:

    • getReportHandler

      public Snmp.ReportHandler getReportHandler()
      Returns the report handler which is used internally to process reports received from command responders.
      Returns:
      the ReportHandler instance.
      Since:
      1.6

    • getCounterSupport

      public CounterSupport getCounterSupport()
      Gets the counter support for Snmp related counters. These are for example: snmp4jStatsRequestTimeouts, snmp4jStatsRequestTimeouts, snmp4jStatsRequestWaitTime
      Returns:
      the counter support if available. If the SNMP4JSettings.getSnmp4jStatistics() value is SNMP4JSettings.Snmp4jStatistics.none then no counter support will be created and no statistics will be collected.
      Since:
      2.4.2

    • setCounterSupport

      public void setCounterSupport(CounterSupport counterSupport)
      Sets the counter support instance to handle counter events on behalf of this Snmp instance.
      Parameters:
      counterSupport - the counter support instance that collects the statistics events created by this Snmp instance. See also getCounterSupport().
      Since:
      2.4.2

    • setTimeoutModel

      public void setTimeoutModel(TimeoutModel timeoutModel)
      Sets the timeout model for this SNMP session. The default timeout model sends retries whenever the time specified by the timeout parameter of the target has elapsed without a response being received for the request. By specifying a different timeout model this behaviour can be changed.
      Parameters:
      timeoutModel - a TimeoutModel instance (must not be null).

    • setReportHandler

      public void setReportHandler(Snmp.ReportHandler reportHandler)
      Sets the report handler and overrides the default report handler.
      Parameters:
      reportHandler - a ReportHandler instance which must not be null.
      Since:
      1.6

    • getPendingSyncRequestCount

      public int getPendingSyncRequestCount()
      Gets the number of currently pending synchronous requests.
      Returns:
      the size of the synchronous request queue.
      Since:
      2.4.2

    • getPendingAsyncRequestCount

      public int getPendingAsyncRequestCount()
      Gets the number of currently pending asynchronous requests.
      Returns:
      the size of the asynchronous request queue.
      Since:
      2.4.2

    • closeTransportMapping

      protected void closeTransportMapping(TransportMapping tm)