uk.co.westhawk.snmp.stack
Class SnmpContextPool

java.lang.Object
  |
  +--uk.co.westhawk.snmp.stack.SnmpContextPool

All Implemented Interfaces:

SnmpContextBasisFace, SnmpContextFace

Direct Known Subclasses:

SnmpContextv2cPool

public class SnmpContextPool

extends java.lang.Object

implements SnmpContextFace

This class contains the pool of SNMP v1 contexts. This class reuses the existings contexts instead of creating a new one everytime.

Everytime a property changes the pool is checked for a SnmpContext context that matches all the new properties of this class. If no such context exists, a new one is made. The Pdus associated with the old context remain associated with the old context.

A counter indicates the number of times the context is referenced. The counter is decreased when destroy is called. When the counter reaches zero, the context is released.

Note that because the underlying context can change when a property is changed and the Pdus remain associated with the old context, all properties have to be set BEFORE a Pdu is send.

Thanks to Seon Lee (slee@virtc.com) for reporting thread safety problems.

Version:

$Revision: 3.14 $ $Date: 2002/11/06 11:27:59 $

Author:

Birgit Arkesteijn

See Also:

SnmpContext, SnmpContextv2cPool, SnmpContextv3Pool

Field Summary

protected java.lang.String	community
protected SnmpContext	context
protected static java.util.Hashtable	contextPool
protected java.lang.String	hostAddr
protected int	hostPort
protected java.lang.String	socketType

Fields inherited from interface uk.co.westhawk.snmp.stack.SnmpContextFace

version_id

Fields inherited from interface uk.co.westhawk.snmp.stack.SnmpContextBasisFace

DEFAULT_PORT, KVM_SOCKET, MAXPDU, MSS, NETSCAPE_SOCKET, STANDARD_SOCKET

Constructor Summary

SnmpContextPool(java.lang.String host, int port)
Constructor.

SnmpContextPool(java.lang.String host, int port, java.lang.String typeSocket)
Constructor.

SnmpContextPool(java.lang.String host, int port, java.lang.String comm, java.lang.String typeSocket)
Constructor.

Method Summary

boolean	addPdu(Pdu pdu) Adds a pdu.
void	addTrapListener(TrapListener l) Adds the specified trap listener.
void	destroy() Releases the resources held by this context.
void	dumpContexts(java.lang.String title) Dumps the pool of contexts.
byte[]	encodePacket(byte msg_type, int rId, int errstat, int errind, java.util.Enumeration ve) Encodes a pdu packet.
java.lang.String	getCommunity() Returns the community name.
java.lang.String	getHashKey() Returns the hash key.
java.lang.String	getHost() Returns the host
protected SnmpContext	getMatchingContext() Returns a context from the pool.
int	getPort() Returns the port number
java.lang.String	getTypeSocket() Returns the type socket
int	getVersion() Return the SNMP version of the context.
Pdu	processIncomingTrap(byte[] message) Processes the incoming trap with the current context.
boolean	removePdu(int requestId) Removes a pdu.
void	removeTrapListener(TrapListener l) Removes the specified trap listener.
void	sendPacket(byte[] packet) Pass a correctly encoded SNMP packet, and we'l send it...
void	setCommunity(java.lang.String newCommunity) Sets the community name.
java.lang.String	toString() Returns a string representation of the object.

Methods inherited from class java.lang.Object

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

Field Detail

contextPool

protected static java.util.Hashtable contextPool

context

protected SnmpContext context

hostAddr

protected java.lang.String hostAddr

socketType

protected java.lang.String socketType

hostPort

protected int hostPort

community

protected java.lang.String community

Constructor Detail

SnmpContextPool

public SnmpContextPool(java.lang.String host,
                       int port)
                throws java.io.IOException

Constructor.

Parameters:

host - The host to which the Pdu will send

port - The port where the SNMP server will be

See Also:

SnmpContext.SnmpContext(String, int)

SnmpContextPool

public SnmpContextPool(java.lang.String host,
                       int port,
                       java.lang.String typeSocket)
                throws java.io.IOException

Constructor.

Parameters:

host - The host to which the Pdu will send

port - The port where the SNMP server will be

typeSocket - The type of socket to use.

See Also:

SnmpContext.SnmpContext(String, int, String), SnmpContextBasisFace.STANDARD_SOCKET, SnmpContextBasisFace.NETSCAPE_SOCKET, SnmpContextBasisFace.KVM_SOCKET

SnmpContextPool

public SnmpContextPool(java.lang.String host,
                       int port,
                       java.lang.String comm,
                       java.lang.String typeSocket)
                throws java.io.IOException

Constructor.

Thanks to Ernest Jones (EJones@netopia.com) for suggesting this constructor.

Parameters:

host - The host to which the Pdu will send

port - The port where the SNMP server will be

comm - The community name.

typeSocket - The type of socket to use.

Since:

4_12

See Also:

SnmpContextBasisFace.STANDARD_SOCKET, SnmpContextBasisFace.NETSCAPE_SOCKET, SnmpContextBasisFace.KVM_SOCKET

Method Detail

getVersion

public int getVersion()

Return the SNMP version of the context.

Specified by:

getVersion in interface SnmpContextBasisFace

Returns:

The version

getHost

public java.lang.String getHost()

Returns the host

Specified by:

getHost in interface SnmpContextBasisFace

Returns:

The host

getPort

public int getPort()

Returns the port number

Specified by:

getPort in interface SnmpContextBasisFace

Returns:

The port no

getTypeSocket

public java.lang.String getTypeSocket()

Returns the type socket

Specified by:

getTypeSocket in interface SnmpContextBasisFace

Returns:

The type socket

getCommunity

public java.lang.String getCommunity()

Returns the community name.

Specified by:

getCommunity in interface SnmpContextFace

See Also:

SnmpContext.getCommunity()

setCommunity

public void setCommunity(java.lang.String newCommunity)

Sets the community name.

Specified by:

setCommunity in interface SnmpContextFace

See Also:

SnmpContext.setCommunity(String)

addPdu

public boolean addPdu(Pdu pdu)
               throws java.io.IOException,
                      PduException

Adds a pdu.

Specified by:

addPdu in interface SnmpContextBasisFace

Parameters:

pdu - the Pdu

Returns:

whether the pdu has been successfully added

removePdu

public boolean removePdu(int requestId)

Removes a pdu.

Specified by:

removePdu in interface SnmpContextBasisFace

Parameters:

rid - the Pdu request id

Returns:

whether the pdu has been successfully removed

encodePacket

public byte[] encodePacket(byte msg_type,
                           int rId,
                           int errstat,
                           int errind,
                           java.util.Enumeration ve)
                    throws java.io.IOException,
                           EncodingException

Encodes a pdu packet.

Specified by:

encodePacket in interface SnmpContextBasisFace

Following copied from interface: uk.co.westhawk.snmp.stack.SnmpContextBasisFace

Returns:

The encoded packet

sendPacket

public void sendPacket(byte[] packet)

Pass a correctly encoded SNMP packet, and we'l send it...

Specified by:

sendPacket in interface SnmpContextBasisFace

Following copied from interface: uk.co.westhawk.snmp.stack.SnmpContextBasisFace

Parameters:

packet - The encoded packet

destroy

public void destroy()

Releases the resources held by this context. This method will decrement the reference counter. When the reference counter reaches zero the actual context is removed from the pool and destroyed.

Specified by:

destroy in interface SnmpContextBasisFace

getMatchingContext

protected SnmpContext getMatchingContext()
                                  throws java.io.IOException

Returns a context from the pool. This methods checks for an existing context that matches all our properties. If such a context does not exist a new one is created and added to the pool.

Returns:

A context from the pool

See Also:

getHashKey()

dumpContexts

public void dumpContexts(java.lang.String title)

Dumps the pool of contexts. This is for debug purposes.

Parameters:

title - The title of the dump

getHashKey

public java.lang.String getHashKey()

Returns the hash key. This key is built out of all properties. It serves as key for the hashtable of (v1) contexts.

Returns:

The hash key

addTrapListener

public void addTrapListener(TrapListener l)
                     throws java.io.IOException

Adds the specified trap listener. The listener will be added to the current context, not to all the contexts in the hashtable.

Specified by:

addTrapListener in interface SnmpContextBasisFace

See Also:

AbstractSnmpContext.addTrapListener(uk.co.westhawk.snmp.event.TrapListener)

removeTrapListener

public void removeTrapListener(TrapListener l)
                        throws java.io.IOException

Removes the specified trap listener. The listener will be removed from the current context, not from all the contexts in the hashtable.

Specified by:

removeTrapListener in interface SnmpContextBasisFace

See Also:

AbstractSnmpContext.removeTrapListener(uk.co.westhawk.snmp.event.TrapListener)

processIncomingTrap

public Pdu processIncomingTrap(byte[] message)
                        throws DecodingException,
                               java.io.IOException

Processes the incoming trap with the current context.

Specified by:

processIncomingTrap in interface SnmpContextBasisFace

See Also:

SnmpContext.processIncomingTrap(byte[])

toString

public java.lang.String toString()

Returns a string representation of the object.

Overrides:

toString in class java.lang.Object

Returns:

The string