Class Snmp
- All Implemented Interfaces:
EventListener
,CommandResponder
,Session
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
-
Nested Class Summary
Modifier and TypeClassDescriptionstatic interface
Interface for handling reports. -
Constructor Summary
ConstructorDescriptionSnmp()
Creates aSnmp
instance that uses aMessageDispatcherImpl
with no message processing models and no security protols (by default).Snmp
(MessageDispatcher messageDispatcher) Creates aSnmp
instance by supplying aMessageDispatcher
.Snmp
(MessageDispatcher messageDispatcher, TransportMapping<? extends Address> transportMapping) Creates aSnmp
instance by supplying aMessageDispatcher
and aTransportMapping
.Snmp
(TransportMapping<? extends Address> transportMapping) Creates aSnmp
instance that uses aMessageDispatcherImpl
with all supported message processing models and the default security protols for dispatching. -
Method Summary
Modifier and TypeMethodDescriptionvoid
addCommandResponder
(CommandResponder listener) Adds aCommandResponder
to this SNMP session.boolean
addNotificationListener
(Address listenAddress, CommandResponder listener) Adds a notification listener to this Snmp instance.boolean
addNotificationListener
(TransportMapping transportMapping, Address listenAddress, CommandResponder listener) Adds a notification listener to this Snmp instance.void
addTransportMapping
(TransportMapping<? extends Address> transportMapping) Adds aTransportMapping
to this SNMP session.void
cancel
(PDU request, ResponseListener listener) Cancels an asynchronous request.void
close()
Closes the session and frees any allocated resources, i.e.protected void
byte[]
discoverAuthoritativeEngineID
(Address address, long timeout) Discovers the engine ID of the SNMPv3 entity denoted by the supplied address.protected void
Fires aCommandResponderEvent
event to inform listeners about a received PDU.Sends a GET request to a target.void
get
(PDU pdu, Target target, Object userHandle, ResponseListener listener) Asynchronously sends a GET requestPDU
to the given target.Sends a GETBULK request to a target.void
getBulk
(PDU pdu, Target target, Object userHandle, ResponseListener listener) Asynchronously sends a GETBULK requestPDU
to the given target.getCachedContextEngineId
(Address targetAddress) Get a cached RFC 5343 context engine ID for the specified address.Gets the counter support for Snmp related counters.byte[]
Gets the local engine ID if the MPv3 is available, otherwise a runtime exception is thrown.Returns the message dispatcher associated with this SNMP session.getMessageProcessingModel
(int messageProcessingModel) Gets the message processing model for the supplied ID.Sends a GETNEXT request to a target.void
getNext
(PDU pdu, Target target, Object userHandle, ResponseListener listener) Asynchronously sends a GETNEXT requestPDU
to the given target.int
Gets the next unique request ID.getNotificationListenerTM
(Address listenAddress) Gets the transport mapping registered for the specified listen address.int
Gets the number of currently pending asynchronous requests.int
Gets the number of currently pending synchronous requests.Returns the report handler which is used internally to process reports received from command responders.Gets the timeout model associated with this SNMP session.getUSM()
Gets the User Based Security Model (USM).protected void
handleInternalResponse
(PDU response, PDU pdu, Address target) Sends an INFORM request to a target.void
inform
(PDU pdu, Target target, Object userHandle, ResponseListener listener) Asynchronously sends an INFORM requestPDU
to the given target.protected final void
boolean
Checks whether RFC5343 based context engine ID discovery is disabled or not.void
listen()
Puts all associated transport mappings into listen mode.protected TransportMapping
lookupTransportMapping
(Target target) void
Sends a SNMPv2c or SNMPv3 notification to a target.void
processPdu
(CommandResponderEvent event) Process an incoming request or notification PDU.removeCachedContextEngineId
(Address target) Remove a cached RFC 5343 context engine ID for the specified address and return it.void
removeCommandResponder
(CommandResponder listener) Removes aCommandResponder
from this SNMP session.boolean
removeNotificationListener
(Address listenAddress) Removes (deletes) the notification listener for the specified transport endpoint.void
removeTransportMapping
(TransportMapping<? extends Address> transportMapping) Removes the specified transport mapping from this SNMP session.protected boolean
resendRequest
(org.snmp4j.Snmp.PendingRequest request, PDU response) Sends aPDU
to the given target and returns the received responsePDU
.void
send
(PDU pdu, Target target, Object userHandle, ResponseListener listener) Asynchronously sends aPDU
to the given target.send
(PDU pdu, Target target, TransportMapping transport) Sends aPDU
to the given target and if thePDU
is a confirmed request, then the received response is returned synchronously.void
send
(PDU pdu, Target target, TransportMapping transport, Object userHandle, ResponseListener listener) Asynchronously sends aPDU
to the given target.protected PduHandle
sendMessage
(PDU pdu, Target target, TransportMapping transport, PduHandleCallback<PDU> pduHandleCallback) Actually sends a PDU to a target and returns a handle for the sent PDU.Sends a SET request to a target.void
set
(PDU pdu, Target target, Object userHandle, ResponseListener listener) Asynchronously sends a SET requestPDU
to the given target.void
setContextEngineIdDiscoveryDisabled
(boolean contextEngineIdDiscoveryDisabled) Sets the RFC5343 based context engine ID discovery.void
setCounterSupport
(CounterSupport counterSupport) Sets the counter support instance to handle counter events on behalf of this Snmp instance.void
setLocalEngine
(byte[] engineID, int engineBoots, int engineTime) Sets the local engine ID for the SNMP entity represented by thisSnmp
instance.void
setMessageDispatcher
(MessageDispatcher messageDispatcher) Sets the message dispatcher associated with this SNMP session.void
setReportHandler
(Snmp.ReportHandler reportHandler) Sets the report handler and overrides the default report handler.void
setTimeoutModel
(TimeoutModel timeoutModel) Sets the timeout model for this SNMP session.void
Sends a SNMPv1 trap to a target.
-
Constructor Details
-
Snmp
public Snmp()Creates aSnmp
instance that uses aMessageDispatcherImpl
with no message processing models and no security protols (by default). You will have to add those by calling the appropriate methods ongetMessageDispatcher()
.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
Creates aSnmp
instance that uses aMessageDispatcherImpl
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 initialTransportMapping
. You can add more or remove the same later.
-
Snmp
public Snmp(MessageDispatcher messageDispatcher, TransportMapping<? extends Address> transportMapping) Creates aSnmp
instance by supplying aMessageDispatcher
and aTransportMapping
.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
- aMessageDispatcher
instance that will be used to dispatch incoming and outgoing messages.transportMapping
- the initialTransportMapping
, which may benull
. You can add or remove transport mappings later usingaddTransportMapping(org.snmp4j.TransportMapping<? extends org.snmp4j.smi.Address>)
andremoveTransportMapping(org.snmp4j.TransportMapping<? extends org.snmp4j.smi.Address>)
respectively.
-
Snmp
Creates aSnmp
instance by supplying aMessageDispatcher
.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
- aMessageDispatcher
instance that will be used to dispatch incoming and outgoing messages.- Since:
- 1.5
-
-
Method Details
-
initMessageDispatcher
protected final void initMessageDispatcher() -
getMessageDispatcher
Returns the message dispatcher associated with this SNMP session.- Returns:
- a
MessageDispatcher
instance. - Since:
- 1.1
-
setMessageDispatcher
Sets the message dispatcher associated with this SNMP session. TheCommandResponder
registration is removed from the existing message dispatcher (if notnull
).- Parameters:
messageDispatcher
- a message dispatcher that processes incoming SNMPPDU
s.- Since:
- 2.5.7
-
addTransportMapping
Adds aTransportMapping
to this SNMP session.- Parameters:
transportMapping
- aTransportMapping
instance.
-
removeTransportMapping
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 addedTransportMapping
.
-
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 providedCommandResponder
with the internalNotificationDispatcher
.- Parameters:
transportMapping
- the TransportMapping that is listening on the provided listenAddress. CallTransportMappings.getInstance().createTransportMapping(listenAddress);
to create such a transport mapping.listenAddress
- theAddress
denoting the transport end-point (interface and port) to listen for incoming notifications.listener
- theCommandResponder
instance that should handle the received notifications.- Returns:
true
if registration was successful andfalse
if, for example, the transport mapping for the listen address could not be created.- Since:
- 2.5.0
-
addNotificationListener
Adds a notification listener to this Snmp instance. Calling this method will create a transport mapping for the specified listening address and registers the providedCommandResponder
with the internalNotificationDispatcher
.- Parameters:
listenAddress
- theAddress
denoting the transport end-point (interface and port) to listen for incoming notifications.listener
- theCommandResponder
instance that should handle the received notifications.- Returns:
true
if registration was successful andfalse
if, for example, the transport mapping for the listen address could not be created.- Since:
- 1.6
-
removeNotificationListener
Removes (deletes) the notification listener for the specified transport endpoint.- Parameters:
listenAddress
- the listenAddress
to be removed.- Returns:
true
if the notification listener has been removed successfully.
-
getNotificationListenerTM
Gets the transport mapping registered for the specified listen address.- Parameters:
listenAddress
- the listen address.- Returns:
- the
TransportMapping
for the specified listen address ornull
if there is no notification listener for that address. - Since:
- 2.5.0
-
listen
Puts all associated transport mappings into listen mode.- Throws:
IOException
- if a transport mapping throws anIOException
when itsTransportMapping.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
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 anull
response and aInterruptedException
in the error member of theResponseEvent
returned.After a
Session
has been closed it must not be used anymore.- Specified by:
close
in interfaceSession
- Throws:
IOException
- if a transport mapping cannot be closed successfully.
-
get
Sends a GET request to a target. This method sets the PDU's type toPDU.GET
and then sends a synchronous request to the supplied target.- Parameters:
pdu
- aPDU
instance. For SNMPv3 messages, the supplied PDU instance has to be aScopedPDU
instance.target
- the Target instance representing the target SNMP engine where to send thepdu
.- Returns:
- the received response encapsulated in a
ResponseEvent
instance. To obtain the received responsePDU
callResponseEvent.getResponse()
. If the request timed out, that method will returnnull
. - 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 requestPDU
to the given target. The response is then returned by calling the suppliedResponseListener
instance.- Parameters:
pdu
- the PDU instance to send.target
- the Target instance representing the target SNMP engine where to send thepdu
.userHandle
- an user defined handle that is returned when the request is returned via thelistener
object.listener
- aResponseListener
instance that is called whenpdu
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
Sends a GETNEXT request to a target. This method sets the PDU's type toPDU.GETNEXT
and then sends a synchronous request to the supplied target. This method is a convenience wrapper for thesend(PDU pdu, Target target)
method.- Parameters:
pdu
- aPDU
instance. For SNMPv3 messages, the supplied PDU instance has to be aScopedPDU
instance.target
- the Target instance representing the target SNMP engine where to send thepdu
.- Returns:
- the received response encapsulated in a
ResponseEvent
instance. To obtain the received responsePDU
callResponseEvent.getResponse()
. If the request timed out, that method will returnnull
. - 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 requestPDU
to the given target. The response is then returned by calling the suppliedResponseListener
instance.- Parameters:
pdu
- the PDU instance to send.target
- the Target instance representing the target SNMP engine where to send thepdu
.userHandle
- an user defined handle that is returned when the request is returned via thelistener
object.listener
- aResponseListener
instance that is called whenpdu
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
Sends a GETBULK request to a target. This method sets the PDU's type toPDU.GETBULK
and then sends a synchronous request to the supplied target. This method is a convenience wrapper for thesend(PDU pdu, Target target)
method.- Parameters:
pdu
- aPDU
instance. For SNMPv3 messages, the supplied PDU instance has to be aScopedPDU
instance.target
- the Target instance representing the target SNMP engine where to send thepdu
.- Returns:
- the received response encapsulated in a
ResponseEvent
instance. To obtain the received responsePDU
callResponseEvent.getResponse()
. If the request timed out, that method will returnnull
. - 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 requestPDU
to the given target. The response is then returned by calling the suppliedResponseListener
instance.- Parameters:
pdu
- the PDU instance to send.target
- the Target instance representing the target SNMP engine where to send thepdu
.userHandle
- an user defined handle that is returned when the request is returned via thelistener
object.listener
- aResponseListener
instance that is called whenpdu
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
Sends an INFORM request to a target. This method sets the PDU's type toPDU.INFORM
and then sends a synchronous request to the supplied target. This method is a convenience wrapper for thesend(PDU pdu, Target target)
method.- Parameters:
pdu
- aPDU
instance. For SNMPv3 messages, the supplied PDU instance has to be aScopedPDU
instance.target
- the Target instance representing the target SNMP engine where to send thepdu
.- Returns:
- the received response encapsulated in a
ResponseEvent
instance. To obtain the received responsePDU
callResponseEvent.getResponse()
. If the request timed out, that method will returnnull
. - 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 requestPDU
to the given target. The response is then returned by calling the suppliedResponseListener
instance.- Parameters:
pdu
- the PDU instance to send.target
- the Target instance representing the target SNMP engine where to send thepdu
.userHandle
- an user defined handle that is returned when the request is returned via thelistener
object.listener
- aResponseListener
instance that is called whenpdu
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
Sends a SNMPv1 trap to a target. This method sets the PDU's type toPDU.V1TRAP
and then sends it to the supplied target. This method is a convenience wrapper for thesend(PDU pdu, Target target)
method.- Parameters:
pdu
- aPDUv1
instance.target
- the Target instance representing the target SNMP engine where to send thepdu
. The selected SNMP protocol version for the target must beSnmpConstants.version1
.- Throws:
IOException
- if the trap cannot be sent.- Since:
- 1.1
-
notify
Sends a SNMPv2c or SNMPv3 notification to a target. This method sets the PDU's type toPDU.NOTIFICATION
and then sends it to the supplied target. This method is a convenience wrapper for thesend(PDU pdu, Target target)
method.- Parameters:
pdu
- aPDUv1
instance.target
- the Target instance representing the target SNMP engine where to send thepdu
. The selected SNMP protocol version for the target must beSnmpConstants.version2c
orSnmpConstants.version2c
.- Throws:
IOException
- if the notification cannot be sent.- Since:
- 1.1
-
set
Sends a SET request to a target. This method sets the PDU's type toPDU.SET
and then sends a synchronous request to the supplied target.- Parameters:
pdu
- aPDU
instance. For SNMPv3 messages, the supplied PDU instance has to be aScopedPDU
instance.target
- the Target instance representing the target SNMP engine where to send thepdu
.- Returns:
- the received response encapsulated in a
ResponseEvent
instance. To obtain the received responsePDU
callResponseEvent.getResponse()
. If the request timed out, that method will returnnull
. - 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 requestPDU
to the given target. The response is then returned by calling the suppliedResponseListener
instance.- Parameters:
pdu
- the PDU instance to send.target
- the Target instance representing the target SNMP engine where to send thepdu
.userHandle
- an user defined handle that is returned when the request is returned via thelistener
object.listener
- aResponseListener
instance that is called whenpdu
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
Description copied from interface:Session
Sends aPDU
to the given target and returns the received responsePDU
.- Specified by:
send
in interfaceSession
- Parameters:
pdu
- thePDU
to send.target
- theTarget
instance that specifies how and where to send the PDU.- Returns:
- the received response encapsulated in a
ResponseEvent
instance. To obtain the received responsePDU
callResponseEvent.getResponse()
. If the request timed out, that method will returnnull
. If the sentpdu
is an unconfirmed PDU (notification, response, or report), thennull
will be returned. - Throws:
IOException
- if the message could not be send.
-
send
Sends aPDU
to the given target and if thePDU
is a confirmed request, then the received response is returned synchronously.- Specified by:
send
in interfaceSession
- Parameters:
pdu
- aPDU
instance. When sending a SNMPv1 trap PDU, the supplied PDU instance must be aPDUv1
. For all types of SNMPv3 messages, the supplied PDU instance has to be aScopedPDU
instance.target
- the Target instance representing the target SNMP engine where to send thepdu
.transport
- specifies theTransportMapping
to be used when sending the PDU. Iftransport
isnull
, the associated message dispatcher will try to determine the transport mapping by thetarget
's address.- Returns:
- the received response encapsulated in a
ResponseEvent
instance. To obtain the received responsePDU
callResponseEvent.getResponse()
. If the request timed out, that method will returnnull
. If the sentpdu
is an unconfirmed PDU (notification, response, or report), thennull
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 aPDU
to the given target. The response is then returned by calling the suppliedResponseListener
instance.- Specified by:
send
in interfaceSession
- Parameters:
pdu
- the PDU instance to send.target
- the Target instance representing the target SNMP engine where to send thepdu
.userHandle
- an user defined handle that is returned when the request is returned via thelistener
object.listener
- aResponseListener
instance that is called whenpdu
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 aPDU
to the given target. The response is then returned by calling the suppliedResponseListener
instance.- Specified by:
send
in interfaceSession
- Parameters:
pdu
- the PDU instance to send.target
- the Target instance representing the target SNMP engine where to send thepdu
.transport
- specifies theTransportMapping
to be used when sending the PDU. Iftransport
isnull
, the associated message dispatcher will try to determine the transport mapping by thetarget
's address.userHandle
- an user defined handle that is returned when the request is returned via thelistener
object.listener
- aResponseListener
instance that is called whenpdu
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
- thePDU
instance to be sent.target
- aTarget
instance denoting the target SNMP entity.transport
- the (optional) transport mapping to be used to send the request. Iftransport
isnull
a suitable transport mapping is determined from thetarget
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
-
cancel
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 theResponseEvent
indicates an error.- Specified by:
cancel
in interfaceSession
- Parameters:
request
- a request PDU as sent viaSession.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 thisSnmp
instance. This is a convenience method that sets the local engine ID in the associatedMPv3
andUSM
.- 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
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 betrue
(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
Gets the User Based Security Model (USM). This is a convenience method that uses theMPv3.getSecurityModel(int)
method of the associated MPv3 instance to get the USM.- Returns:
- the
USM
instance associated with the MPv3 bound to thisSnmp
instance, ornull
otherwise.
-
getMessageProcessingModel
Gets the message processing model for the supplied ID.- Parameters:
messageProcessingModel
- a mesage processing model ID as defined inMessageProcessingModel
.- Returns:
- MessageProcessingModel a
MessageProcessingModel
ifmessageProcessingModel
has been registered with the message dispatcher associated with this SNMP session.
-
processPdu
Process an incoming request or notification PDU.- Specified by:
processPdu
in interfaceCommandResponder
- Parameters:
event
- aCommandResponderEvent
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 isfalse
.- 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 isfalse
.- Parameters:
contextEngineIdDiscoveryDisabled
-true
to disable context engine ID discovery,false
to enable context engine ID discovery.- Since:
- 2.0
-
getCachedContextEngineId
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 withremoveCachedContextEngineId(Address)
or implicitly because the address object was no longer associated with any open connection (i.e., the internallyWeakHashMap
recognized no more active references on the address key). - Since:
- 2.8.10
-
removeCachedContextEngineId
Remove a cached RFC 5343 context engine ID for the specified address and return it. To remove all cached IDs, callsetContextEngineIdDiscoveryDisabled(boolean)
withtrue
.- 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
-
handleInternalResponse
-
removeCommandResponder
Removes aCommandResponder
from this SNMP session.- Parameters:
listener
- a previously addedCommandResponder
instance.
-
addCommandResponder
Adds aCommandResponder
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
- theCommandResponder
instance to be added.
-
fireProcessPdu
Fires aCommandResponderEvent
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
- aCommandResponderEvent
.
-
getTimeoutModel
Gets the timeout model associated with this SNMP session.- Returns:
- a TimeoutModel instance (never
null
). - See Also:
-
getReportHandler
Returns the report handler which is used internally to process reports received from command responders.- Returns:
- the
ReportHandler
instance. - Since:
- 1.6
-
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 isSNMP4JSettings.Snmp4jStatistics.none
then no counter support will be created and no statistics will be collected. - Since:
- 2.4.2
-
setCounterSupport
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 alsogetCounterSupport()
.- Since:
- 2.4.2
-
setTimeoutModel
Sets the timeout model for this SNMP session. The default timeout model sends retries whenever the time specified by thetimeout
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
- aTimeoutModel
instance (must not benull
).
-
setReportHandler
Sets the report handler and overrides the default report handler.- Parameters:
reportHandler
- aReportHandler
instance which must not benull
.- 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
-