Module org.snmp4j

Package org.snmp4j.transport

Class AbstractTransportMapping<A extends Address>

java.lang.Object

org.snmp4j.transport.AbstractTransportMapping<A>

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, TransportMapping<A>

Direct Known Subclasses:

DummyTransport, DummyTransport.DummyTransportResponder, TcpTransportMapping, UdpTransportMapping

public abstract class AbstractTransportMapping<A extends Address>
extends java.lang.Object
implements TransportMapping<A>

The AbstractTransportMapping provides an abstract implementation for the message dispatcher list and the maximum inbound message size.

Version:

3.6.0

Field Summary

Fields

Modifier and Type	Field	Description
protected boolean	asyncMsgProcessingSupported
protected WorkerTask	listenWorkerTask
private static LogAdapter	logger
protected int	maxInboundMessageSize
protected java.util.Set<A>	suspendedAddresses
protected java.util.List<TransportListener>	transportListener

Constructor Summary

Constructors

Constructor	Description
AbstractTransportMapping()

Method Summary

Modifier and Type	Method	Description
void	addTransportListener(TransportListener l)	Adds a transport listener to the transport.
abstract void	close()	Closes the transport an releases all bound resources synchronously.
protected void	fireProcessMessage(A address, java.nio.ByteBuffer buf, TransportStateReference tmStateReference)
protected abstract WorkerTask	getListenerWorkerTask()	Gets the WorkerTask that is responsible for receiving new messages.
int	getMaxInboundMessageSize()	Gets the maximum length of an incoming message that can be successfully processed by this transport mapping implementation.
int	getPriority()	Returns the priority of the internal listen thread.
abstract java.lang.Class<? extends Address>	getSupportedAddressClass()	Gets the primary Address class that is supported by this transport mapping.
java.lang.String	getThreadName()	Returns the name of the listen thread.
protected void	handleDroppedMessageToSend(A address, byte[] message, TransportStateReference transportStateReference, long timeoutMillis, int maxRetries)	Handle a message that could not be send to the specified address, because there is no server socket for receiving responses.
boolean	isAsyncMsgProcessingSupported()	Returns true if asynchronous (multi-threaded) message processing may be implemented.
boolean	isListening()	Returns true if the transport mapping is listening for incoming messages.
abstract void	listen()	Listen for incoming messages.
void	removeAllTransportListeners()
void	removeTransportListener(TransportListener l)	Removes a transport listener.
boolean	resumeAddress(A addressToResumeSending)	Resume sending of messages to the specified address.
abstract void	sendMessage(A address, byte[] message, TransportStateReference tmStateReference, long timeoutMillis, int maxRetries)	Sends a message to the supplied address using this transport.
void	setAsyncMsgProcessingSupported(boolean asyncMsgProcessingSupported)	Specifies whether this transport mapping has to support asynchronous messages processing or not.
void	setPriority(int newPriority)	Changes the priority of the listen thread for this UDP transport mapping.
void	setThreadName(java.lang.String name)	Sets the name of the listen thread for this UDP transport mapping.
void	suspendAddress(A addressToSuspendSending)	Suspend sending of messages to the specified address, regardless if a connection is already established or not.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.snmp4j.TransportMapping

getListenAddress, getSupportedAddressClasses, getSupportedTransportType, isAddressSupported, isAddressSupported

Field Detail

logger

private static final LogAdapter logger

transportListener

protected java.util.List<TransportListener> transportListener

maxInboundMessageSize

protected int maxInboundMessageSize

asyncMsgProcessingSupported

protected boolean asyncMsgProcessingSupported

suspendedAddresses

protected java.util.Set<A extends Address> suspendedAddresses

listenWorkerTask

protected WorkerTask listenWorkerTask

Constructor Detail

AbstractTransportMapping

public AbstractTransportMapping()

Method Detail

getSupportedAddressClass

public abstract java.lang.Class<? extends Address> getSupportedAddressClass()

Description copied from interface: TransportMapping

Gets the primary Address class that is supported by this transport mapping.

Specified by:

getSupportedAddressClass in interface TransportMapping<A extends Address>

Returns:

a subclass of Address.

isListening

public boolean isListening()

Description copied from interface: TransportMapping

Returns true if the transport mapping is listening for incoming messages. For connection oriented transport mappings this is a prerequisite to be able to send SNMP messages. For connectionless transport mappings it is a prerequisite to be able to receive responses.

Specified by:

isListening in interface TransportMapping<A extends Address>

Returns:

true if this transport mapping is listening for messages.

sendMessage

public abstract void sendMessage(A address,
                                 byte[] message,
                                 TransportStateReference tmStateReference,
                                 long timeoutMillis,
                                 int maxRetries)
                          throws java.io.IOException

Sends a message to the supplied address using this transport. If the target address has been suspended, then instead actually sending the message on the wire, the method handleDroppedMessageToSend(Address, byte[], TransportStateReference, long, int) will be called. To stop suspending of a target address, call resumeAddress(Address) for that address.

Specified by:

sendMessage in interface TransportMapping<A extends Address>

Parameters:

address - an Address instance denoting the target address.

message - the whole message as an array of bytes.

tmStateReference - the (optional) transport model state reference as defined by RFC 5590 section 6.1.

timeoutMillis - maximum number of milli seconds the connection creation might take (if connection based).

maxRetries - maximum retries during connection creation.

Throws:

java.io.IOException - if any underlying IO operation fails.

addTransportListener

public void addTransportListener(TransportListener l)

Description copied from interface: TransportMapping

Adds a transport listener to the transport. Normally, at least one transport listener needs to be added to process incoming messages.

Specified by:

addTransportListener in interface TransportMapping<A extends Address>

Parameters:

l - a TransportListener instance.

removeTransportListener

public void removeTransportListener(TransportListener l)

Description copied from interface: TransportMapping

Removes a transport listener. Incoming messages will no longer be propagated to the supplied TransportListener.

Specified by:

removeTransportListener in interface TransportMapping<A extends Address>

Parameters:

l - a TransportListener instance.

removeAllTransportListeners

public void removeAllTransportListeners()

fireProcessMessage

protected void fireProcessMessage(A address,
                                  java.nio.ByteBuffer buf,
                                  TransportStateReference tmStateReference)

close

public abstract void close()
                    throws java.io.IOException

Description copied from interface: TransportMapping

Closes the transport an releases all bound resources synchronously.

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface TransportMapping<A extends Address>

Throws:

java.io.IOException - if any IO operation for the close fails.

suspendAddress

public void suspendAddress(A addressToSuspendSending)

Suspend sending of messages to the specified address, regardless if a connection is already established or not. To be able to send messages again to the specified address using sendMessage(Address, byte[], TransportStateReference, long, int), call resumeAddress(Address).

Parameters:

addressToSuspendSending - an arbitrary remote address for which any messages send by sendMessage(Address, byte[], TransportStateReference, long, int) should be dropped before sending and reopening a connection to that address.

Since:

3.4.4

resumeAddress

public boolean resumeAddress(A addressToResumeSending)

Resume sending of messages to the specified address.

Parameters:

addressToResumeSending - an arbitrary remote address for which any messages send by sendMessage(Address, byte[], TransportStateReference, long, int) should be dropped before sending and reopening a connection to that address.

Returns:

true if the specified address was previously suspended and is now resumed to allow sending messages, false otherwise.

Since:

3.4.4

handleDroppedMessageToSend

protected void handleDroppedMessageToSend(A address,
                                          byte[] message,
                                          TransportStateReference transportStateReference,
                                          long timeoutMillis,
                                          int maxRetries)

Handle a message that could not be send to the specified address, because there is no server socket for receiving responses.

Parameters:

address - an Address instance denoting the target address.

message - the whole message as an array of bytes.

transportStateReference - the (optional) transport model state reference as defined by RFC 5590 section 6.1.

timeoutMillis - maximum number of milli seconds the connection creation might take (if connection based).

maxRetries - maximum retries during connection creation.

Since:

3.4.4

listen

public abstract void listen()
                     throws java.io.IOException

Description copied from interface: TransportMapping

Listen for incoming messages. For connection oriented transports, this method needs to be called before TransportMapping.sendMessage(A, byte[], org.snmp4j.TransportStateReference, long, int) is called for the first time.

Specified by:

listen in interface TransportMapping<A extends Address>

Throws:

java.io.IOException - if an IO operation exception occurs while starting the listener.

getMaxInboundMessageSize

public int getMaxInboundMessageSize()

Description copied from interface: TransportMapping

Gets the maximum length of an incoming message that can be successfully processed by this transport mapping implementation.

Specified by:

getMaxInboundMessageSize in interface TransportMapping<A extends Address>

Returns:

an integer > 484.

isAsyncMsgProcessingSupported

public boolean isAsyncMsgProcessingSupported()

Returns true if asynchronous (multi-threaded) message processing may be implemented. The default is true.

Returns:

if false is returned the MessageDispatcher.processMessage(org.snmp4j.TransportMapping, org.snmp4j.smi.Address, java.nio.ByteBuffer, org.snmp4j.TransportStateReference) method must not return before the message has been entirely processed.

setAsyncMsgProcessingSupported

public void setAsyncMsgProcessingSupported(boolean asyncMsgProcessingSupported)

Specifies whether this transport mapping has to support asynchronous messages processing or not.

Parameters:

asyncMsgProcessingSupported - if false the MessageDispatcher.processMessage(org.snmp4j.TransportMapping, org.snmp4j.smi.Address, java.nio.ByteBuffer, org.snmp4j.TransportStateReference) method must not return before the message has been entirely processed, because the incoming message buffer is not copied before the message is being processed. If true the message buffer is copied for each call, so that the message processing can be implemented asynchronously.

setPriority

public void setPriority(int newPriority)

Changes the priority of the listen thread for this UDP transport mapping. This method has no effect, if called before listen() has been called for this transport mapping.

Parameters:

newPriority - the new priority.

Since:

3.6.0

See Also:

Thread.setPriority(int)

getPriority

public int getPriority()

Returns the priority of the internal listen thread.

Returns:

a value between Thread.MIN_PRIORITY and Thread.MAX_PRIORITY.

Since:

3.6.0

setThreadName

public void setThreadName(java.lang.String name)

Sets the name of the listen thread for this UDP transport mapping. This method has no effect, if called before listen() has been called for this transport mapping.

Parameters:

name - the new thread name.

Since:

3.6.0

getThreadName

public java.lang.String getThreadName()

Returns the name of the listen thread.

Returns:

the thread name if in listening mode, otherwise null.

Since:

3.6.0

getListenerWorkerTask

protected abstract WorkerTask getListenerWorkerTask()

Gets the WorkerTask that is responsible for receiving new messages.

Returns:

a WorkerTask instance which is most likely a DefaultThreadFactory.WorkerThread.

Since:

3.6.0