Package org.snmp4j
Interface MessageDispatcher
- All Superinterfaces:
TransportListener
- All Known Implementing Classes:
MessageDispatcherImpl
,MultiThreadedMessageDispatcher
The
MessageDispatcher
interface defines common services of
instances that process incoming SNMP messages and dispatch them to
interested CommandResponder
instances. It also provides a service
to send out outgoing SNMP messages.
A MessageDispatcher
needs at least one TransportMapping
and at least one MessageProcessingModel
in order to be able to
process any messages.- Version:
- 2.0
- Author:
- Frank Fock
-
Method Summary
Modifier and TypeMethodDescriptionvoid
addCommandResponder
(CommandResponder listener) Adds aCommandResponder
instance to the message dispatcher.void
Adds aMessageProcessingModel
to the dispatcher.void
addTransportMapping
(TransportMapping<? extends Address> transport) Adds aTransportMapping
to the dispatcher.getMessageProcessingModel
(int messageProcessingModel) Gets theMessageProcessingModel
for the supplied message processing model ID.int
Gets the next unique request ID.getTransport
(Address destAddress) Returns a transport mapping that can handle the supplied address.Gets theCollection
of transport mappings in this message dispatcher.void
processMessage
(TransportMapping sourceTransport, Address incomingAddress, ByteBuffer wholeMessage, TransportStateReference tmStateReference) Process an incoming SNMP message.void
releaseStateReference
(int messageProcessingModel, PduHandle pduHandle) Release any state references associated with the suppliedPduHandle
in the specified message processing model.void
removeCommandResponder
(CommandResponder listener) Removes a previously addedCommandResponder
instance from the message dispatcher.void
Removes a previously addedMessageProcessingModel
from the dispatcher.removeTransportMapping
(TransportMapping<? extends Address> transport) Removes a previously addedTransportMapping
from the dispatcher.int
returnResponsePdu
(int messageProcessingModel, int securityModel, byte[] securityName, int securityLevel, PDU pdu, int maxSizeResponseScopedPDU, StateReference stateReference, StatusInformation statusInformation) Returns a response PDU to the sender of the corresponding request PDU.Sends a PDU to the supplied transport address.sendPdu
(TransportMapping transportMapping, Target target, PDU pdu, boolean expectResponse) Sends a PDU to the supplied transport address.sendPdu
(TransportMapping transportMapping, Target target, PDU pdu, boolean expectResponse, PduHandleCallback<PDU> callback) Sends a PDU to the supplied transport address and returns thePduHandle
that uniquely identifies the request as response after the request has been sent and optional, if aPduHandleCallback
is given, it returns also thePduHandle
just before the request is sent through the the callback interface.
-
Method Details
-
getNextRequestID
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
-
addMessageProcessingModel
Adds aMessageProcessingModel
to the dispatcher. In order to support a specific SNMP protocol version, the message dispatcher needs a message processing model to process messages before they can be dispatched.- Parameters:
model
- aMessageProcessingModel
instance.
-
removeMessageProcessingModel
Removes a previously addedMessageProcessingModel
from the dispatcher.- Parameters:
model
- aMessageProcessingModel
instance.
-
getMessageProcessingModel
Gets theMessageProcessingModel
for the supplied message processing model ID.- Parameters:
messageProcessingModel
- a message processing model ID (seeMessageProcessingModel.getID()
).- Returns:
- a MessageProcessingModel instance if the ID is known, otherwise
null
-
addTransportMapping
Adds aTransportMapping
to the dispatcher. The transport mapping is used to send and receive messages to/from the network.- Parameters:
transport
- aTransportMapping
instance.
-
removeTransportMapping
Removes a previously addedTransportMapping
from the dispatcher.- Parameters:
transport
- aTransportMapping
instance.- Returns:
- the
TransportMapping
instance supplied if it could be successfully removed,null
otherwise.
-
getTransportMappings
Collection<TransportMapping> getTransportMappings()Gets theCollection
of transport mappings in this message dispatcher.- Returns:
- a Collection with the registered transport mappings.
-
getTransport
Returns a transport mapping that can handle the supplied address.- Parameters:
destAddress
- an Address instance.- Returns:
- a
TransportMapping
instance that can be used to sent a SNMP message todestAddress
ornull
if such a transport mapping does not exists. - Since:
- 1.6
-
addCommandResponder
Adds aCommandResponder
instance to the message dispatcher. Successfully processed SNMP messages will be presented to all command responder (in the order in which they have been added) until a responder uses theCommandResponderEvent.setProcessed(boolean processed)
to set the processed status of the event totrue
.- Parameters:
listener
- aCommandResponder
instance.
-
removeCommandResponder
Removes a previously addedCommandResponder
instance from the message dispatcher.- Parameters:
listener
- aCommandResponder
instance.
-
sendPdu
PduHandle sendPdu(TransportMapping transportMapping, Target target, PDU pdu, boolean expectResponse) throws MessageException Sends a PDU to the supplied transport address.- Parameters:
transportMapping
- theTransportMapping
to be used to send the PDU. IftransportMapping
isnull
the message dispatcher will determine the appropriate transport mapping for the given transport address.target
- the target which identifies, transport address, message processing model, security model, security name and level.pdu
- the SNMP Protocol Data UnitexpectResponse
-true
if a response is expected and a state reference should be saved (if needed for the supplied message processing model).- Returns:
- an
PduHandle
that uniquely identifies this request. - Throws:
MessageException
- if sending of the PDU failed.
-
sendPdu
PduHandle sendPdu(TransportMapping transportMapping, Target target, PDU pdu, boolean expectResponse, PduHandleCallback<PDU> callback) throws MessageException Sends a PDU to the supplied transport address and returns thePduHandle
that uniquely identifies the request as response after the request has been sent and optional, if aPduHandleCallback
is given, it returns also thePduHandle
just before the request is sent through the the callback interface.- Parameters:
transportMapping
- theTransportMapping
to be used to send the PDU. IftransportMapping
isnull
the message dispatcher will determine the appropriate transport mapping for the given transport address.target
- the target which identifies, transport address, message processing model, security model, security name and level.pdu
- the SNMP Protocol Data UnitexpectResponse
-true
if a response is expected and a state reference should be saved (if needed for the supplied message processing model).callback
- an optional callback instance that is informed (if notnull
) about the newly assigned PduHandle just before the message is sent out.- Returns:
- an
PduHandle
that uniquely identifies this request. - Throws:
MessageException
- if sending of the PDU failed.
-
sendPdu
Sends a PDU to the supplied transport address. This method behaves like a call tosendPdu(TransportMapping transportMapping, Target target, PDU pdu, boolean expectResponse)
withtransportMapping
set tonull
.- Parameters:
target
- the target which identifies, transport address, message processing model, security model, security name and level.pdu
- the SNMP Protocol Data UnitexpectResponse
-true
if a response is expected and a state reference should be saved (if needed for the supplied message processing model).- Returns:
- an
PduHandle
that uniquely identifies this request. - Throws:
MessageException
- if sending of the PDU failed.
-
returnResponsePdu
int returnResponsePdu(int messageProcessingModel, int securityModel, byte[] securityName, int securityLevel, PDU pdu, int maxSizeResponseScopedPDU, StateReference stateReference, StatusInformation statusInformation) throws MessageException Returns a response PDU to the sender of the corresponding request PDU.- Parameters:
messageProcessingModel
- intsecurityModel
- intsecurityName
- byte[]securityLevel
- intpdu
- PDUmaxSizeResponseScopedPDU
- intstateReference
- StateReferencestatusInformation
- StatusInformation- Returns:
- an MP error status or
SnmpConstants.SNMP_MP_OK
if the operation was successful. - Throws:
MessageException
- if message processing fails with a fatal error.
-
processMessage
void processMessage(TransportMapping sourceTransport, Address incomingAddress, ByteBuffer wholeMessage, TransportStateReference tmStateReference) Process an incoming SNMP message. The message is processed and dispatched according to the message's content, the message processing models, and the command responder available to the dispatcher.- Specified by:
processMessage
in interfaceTransportListener
- Parameters:
sourceTransport
- aTransportMapping
instance denoting the transport that received the message and that will be used to send any responses to this message. ThesourceTransport
has to support theincomingAddress
's implementation class.incomingAddress
- theAddress
from which the message has been received.wholeMessage
- anByteBuffer
containing the received SNMP message.tmStateReference
- the transport model state reference as defined by RFC 5590.
-
releaseStateReference
Release any state references associated with the suppliedPduHandle
in the specified message processing model.- Parameters:
messageProcessingModel
- a message processing model ID.pduHandle
- thePduHandle
that identifies a confirmed class message.- See Also:
-