Module org.snmp4j

Package org.snmp4j.transport

Class DefaultTcpTransportMapping

java.lang.Object

org.snmp4j.transport.AbstractTransportMapping<TcpAddress>

org.snmp4j.transport.AbstractConnectionOrientedTransportMapping<TcpAddress,DefaultTcpTransportMapping.SocketEntry>

org.snmp4j.transport.TcpTransportMapping<DefaultTcpTransportMapping.SocketEntry>

org.snmp4j.transport.DefaultTcpTransportMapping

All Implemented Interfaces:

Closeable, AutoCloseable, ConnectionOrientedTransportMapping<TcpAddress>, TransportMapping<TcpAddress>

public class DefaultTcpTransportMapping
extends TcpTransportMapping<DefaultTcpTransportMapping.SocketEntry>

The DefaultTcpTransportMapping implements a TCP transport mapping with the Java 1.4 new IO API.

It uses a single thread for processing incoming and outgoing messages. The thread is started when the listen method is called, or when an outgoing request is sent using the sendMessage method.

Version:

3.0

Author:

Frank Fock

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected class	DefaultTcpTransportMapping.ServerThread
static class	DefaultTcpTransportMapping.SnmpMesssageLengthDecoder
protected static class	DefaultTcpTransportMapping.SocketEntry

Field Summary

Fields

Modifier and Type	Field	Description
static final int	DEFAULT_MAX_BUSY_LOOPS	The maximum number of loops trying to read data from an incoming port but no data has been received.
protected MessageLengthDecoder	messageLengthDecoder
protected DefaultTcpTransportMapping.ServerThread	serverThread

Fields inherited from class org.snmp4j.transport.TcpTransportMapping

openSocketOnSending, tcpAddress

Fields inherited from class org.snmp4j.transport.AbstractConnectionOrientedTransportMapping

serverEnabled, sockets

Fields inherited from class org.snmp4j.transport.AbstractTransportMapping

asyncMsgProcessingSupported, connectionTimeout, listenWorkerTask, maxInboundMessageSize, socketCleaner, suspendedAddresses, transportListener, transportStateListeners

Constructor Summary

Constructors

Constructor	Description
DefaultTcpTransportMapping()	Creates a default TCP transport mapping with the server for incoming messages disabled.
DefaultTcpTransportMapping(TcpAddress serverAddress)	Creates a default TCP transport mapping that binds to the given address (interface) on the local host and enables server mode (i.e.
DefaultTcpTransportMapping(TcpAddress serverAddress, boolean serverEnabled)	Creates a default TCP transport mapping that binds to the given address (interface) on the local host and enables server mode on request.

Method Summary

Modifier and Type	Method	Description
protected void	addBufferToReadBuffer(DefaultTcpTransportMapping.SocketEntry entry, ByteBuffer byteBuffer)
TcpAddress	getListenAddress()	Returns the address that represents the actual incoming address this transport mapping uses to listen for incoming packets.
MessageLengthDecoder	getMessageLengthDecoder()	Returns the MessageLengthDecoder used by this transport mapping.
CommonTimer	getSocketCleaner()	Gets the CommonTimer that controls socket cleanup operations.
TransportType	getSupportedTransportType()	Gets the TransportType this TransportMapping supports depending on AbstractConnectionOrientedTransportMapping.isServerEnabled().
void	listen()	Listen for incoming and outgoing requests.
void	sendMessage(TcpAddress address, byte[] message, TransportStateReference tmStateReference, long timeoutMillis, int maxRetries)	Sends a SNMP message to the supplied address.
void	setMaxInboundMessageSize(int maxInboundMessageSize)	Sets the maximum buffer size for incoming requests.
void	setMessageLengthDecoder(MessageLengthDecoder messageLengthDecoder)	Sets the message length decoder.
protected void	socketClosedRemotely(SelectionKey sk, SocketChannel readChannel, TcpAddress incomingAddress)
void	wakeupServerSelector()

Methods inherited from class org.snmp4j.transport.TcpTransportMapping

getAddress, getSupportedAddressClass, isOpenSocketOnSending, setOpenSocketOnSending

Methods inherited from class org.snmp4j.transport.AbstractConnectionOrientedTransportMapping

cancelNonServerSelectionKey, close, close, closeSockets, getConnectionTimeout, getMaxBusyLoops, getSockets, isServerEnabled, setConnectionTimeout, setMaxBusyLoops, setServerEnabled, setSocketOptions, timeoutSocket

Methods inherited from class org.snmp4j.transport.AbstractTransportMapping

addTransportListener, addTransportStateListener, fireConnectionStateChanged, fireProcessMessage, getListenWorkerTask, getMaxInboundMessageSize, getPriority, getSuspendedAddresses, getThreadName, handleDroppedMessageToSend, isAsyncMsgProcessingSupported, isListening, removeAllTransportListeners, removeTransportListener, removeTransportStateListener, resumeAddress, setAsyncMsgProcessingSupported, setPriority, setThreadName, suspendAddress

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.snmp4j.transport.ConnectionOrientedTransportMapping

addTransportStateListener, close, getConnectionTimeout, isServerEnabled, removeTransportStateListener, resumeAddress, setConnectionTimeout, setServerEnabled, suspendAddress

Methods inherited from interface org.snmp4j.TransportMapping

addTransportListener, close, getMaxInboundMessageSize, getMaxOutboundMessageSize, getSupportedAddressClasses, isAddressSupported, isAddressSupported, isListening, removeTransportListener

Field Details

DEFAULT_MAX_BUSY_LOOPS

public static final int DEFAULT_MAX_BUSY_LOOPS

The maximum number of loops trying to read data from an incoming port but no data has been received. A value of 0 or less disables the check.

See Also:

• Constant Field Values

serverThread

protected DefaultTcpTransportMapping.ServerThread serverThread

messageLengthDecoder

protected MessageLengthDecoder messageLengthDecoder

Constructor Details

DefaultTcpTransportMapping

public DefaultTcpTransportMapping()
                           throws IOException

Creates a default TCP transport mapping with the server for incoming messages disabled.

Throws:

IOException - on failure of binding a local port.

DefaultTcpTransportMapping

public DefaultTcpTransportMapping(TcpAddress serverAddress,
 boolean serverEnabled)
                           throws IOException

Creates a default TCP transport mapping that binds to the given address (interface) on the local host and enables server mode on request.

Parameters:

serverAddress - the TcpAddress instance that describes the server address to listen on incoming connection requests.

serverEnabled - if true the server mode is enabled and incoming new connections are accepted. Use false to allow outgoing messages and their responses only (client mode).

Throws:

IOException - if the given address cannot be bound.

DefaultTcpTransportMapping

public DefaultTcpTransportMapping(TcpAddress serverAddress)
                           throws IOException

Creates a default TCP transport mapping that binds to the given address (interface) on the local host and enables server mode (i.e. accepts incoming new connections).

Parameters:

serverAddress - the TcpAddress instance that describes the server address to listen on incoming connection requests.

Throws:

IOException - if the given address cannot be bound.

Method Details

listen

public void listen()
            throws IOException

Listen for incoming and outgoing requests. If the serverEnabled member is false the server for incoming requests is not started. This starts the internal server thread that processes messages.

Specified by:

listen in interface TransportMapping<TcpAddress>

Specified by:

listen in class TcpTransportMapping<DefaultTcpTransportMapping.SocketEntry>

Throws:

SocketException - when the transport is already listening for incoming/outgoing messages.

IOException - if the listen port could not be bound to the server thread.

getSupportedTransportType

public TransportType getSupportedTransportType()

Gets the TransportType this TransportMapping supports depending on AbstractConnectionOrientedTransportMapping.isServerEnabled().

Returns:

TransportType.any if AbstractConnectionOrientedTransportMapping.isServerEnabled() is true and TransportType.sender otherwise.

Since:

3.2.0

sendMessage

public void sendMessage(TcpAddress address,
 byte[] message,
 TransportStateReference tmStateReference,
 long timeoutMillis,
 int maxRetries)
                 throws IOException

Sends a SNMP message to the supplied address.

Specified by:

sendMessage in interface TransportMapping<TcpAddress>

Specified by:

sendMessage in class TcpTransportMapping<DefaultTcpTransportMapping.SocketEntry>

Parameters:

address - an TcpAddress. A ClassCastException is thrown if address is not a TcpAddress instance.

message - byte[] the message to sent.

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

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

maxRetries - maximum retries during connection creation.

Throws:

IOException - if an IO exception occurs while trying to send the message.

getMessageLengthDecoder

public MessageLengthDecoder getMessageLengthDecoder()

Description copied from class: TcpTransportMapping

Returns the MessageLengthDecoder used by this transport mapping.

Specified by:

getMessageLengthDecoder in interface ConnectionOrientedTransportMapping<TcpAddress>

Specified by:

getMessageLengthDecoder in class TcpTransportMapping<DefaultTcpTransportMapping.SocketEntry>

Returns:

a MessageLengthDecoder instance.

setMessageLengthDecoder

public void setMessageLengthDecoder(MessageLengthDecoder messageLengthDecoder)

Sets the message length decoder. Default message length decoder is the DefaultTcpTransportMapping.SnmpMesssageLengthDecoder. The message length decoder must be able to decode the total length of a message for this transport mapping protocol(s).

Specified by:

setMessageLengthDecoder in interface ConnectionOrientedTransportMapping<TcpAddress>

Specified by:

setMessageLengthDecoder in class TcpTransportMapping<DefaultTcpTransportMapping.SocketEntry>

Parameters:

messageLengthDecoder - a MessageLengthDecoder instance.

getSocketCleaner

public CommonTimer getSocketCleaner()

Gets the CommonTimer that controls socket cleanup operations.

Specified by:

getSocketCleaner in interface ConnectionOrientedTransportMapping<TcpAddress>

Overrides:

getSocketCleaner in class AbstractTransportMapping<TcpAddress>

Returns:

a socket cleaner timer.

Since:

3.0

setMaxInboundMessageSize

public void setMaxInboundMessageSize(int maxInboundMessageSize)

Sets the maximum buffer size for incoming requests. When SNMP packets are received that are longer than this maximum size, the messages will be silently dropped and the connection will be closed.

Parameters:

maxInboundMessageSize - the length of the inbound buffer in bytes.

getListenAddress

public TcpAddress getListenAddress()

Description copied from interface: TransportMapping

Returns the address that represents the actual incoming address this transport mapping uses to listen for incoming packets.

Specified by:

getListenAddress in interface TransportMapping<TcpAddress>

Overrides:

getListenAddress in class TcpTransportMapping<DefaultTcpTransportMapping.SocketEntry>

Returns:

the address for incoming packets or null this transport mapping is not configured to listen for incoming packets.

wakeupServerSelector

public void wakeupServerSelector()

Specified by:

wakeupServerSelector in class AbstractConnectionOrientedTransportMapping<TcpAddress,DefaultTcpTransportMapping.SocketEntry>

addBufferToReadBuffer

protected void addBufferToReadBuffer(DefaultTcpTransportMapping.SocketEntry entry,
 ByteBuffer byteBuffer)

socketClosedRemotely

protected void socketClosedRemotely(SelectionKey sk,
 SocketChannel readChannel,
 TcpAddress incomingAddress)
                             throws IOException

Throws:

IOException