/* * @(#)file SnmpUserDataFactory.java * @(#)author Sun Microsystems, Inc. * @(#)version 1.16 * @(#)date 06/05/03 * * Copyright 2004 Sun Microsystems, Inc. All rights reserved. * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. */ package com.sun.jmx.snmp.agent; import com.sun.jmx.snmp.SnmpPduPacket; import com.sun.jmx.snmp.SnmpPdu; import com.sun.jmx.snmp.SnmpStatusException; /** * This interface is provided to enable fine customization of the SNMP * agent behaviour. * *
You will not need to implement this interface except if your agent * needs extra customization requiring some contextual information.
* *If an SnmpUserDataFactory is set on the SnmpAdaptorServer, then a new * object containing user-data will be allocated through this factory * for each incoming request. This object will be passed along to * the SnmpMibAgent within SnmpMibRequest objects. By default, no * SnmpUserDataFactory is set on the SnmpAdaptorServer, and the contextual * object passed to SnmpMibAgent is null.
* *You can use this feature to obtain on contextual information * (such as community string etc...) or to implement a caching * mechanism, or for whatever purpose might be required by your specific * agent implementation.
* *The sequence allocateUserData() / releaseUserData()
can
* also be used to implement a caching mechanism:
*
allocateUserData()
could be used to allocate
* some cache space,releaseUserData()
could be used to flush it.This API is a Sun Microsystems internal API and is subject * to change without notice.
* @see com.sun.jmx.snmp.agent.SnmpMibRequest * @see com.sun.jmx.snmp.agent.SnmpMibAgent * @see com.sun.jmx.snmp.daemon.SnmpAdaptorServer * **/ public interface SnmpUserDataFactory { /** * Called by theSnmpAdaptorServer
adaptor.
* Allocate a contextual object containing some user data. This method
* is called once for each incoming SNMP request. The scope
* of this object will be the whole request. Since the request can be
* handled in several threads, the user should make sure that this
* object can be accessed in a thread-safe manner. The SNMP framework
* will never access this object directly - it will simply pass
* it to the SnmpMibAgent
within
* SnmpMibRequest
objects - from where it can be retrieved
* through the {@link com.sun.jmx.snmp.agent.SnmpMibRequest#getUserData() getUserData()} accessor.
* null
is considered to be a valid return value.
*
* This method is called just after the SnmpPduPacket has been
* decoded.
*
* @param requestPdu The SnmpPduPacket received from the SNMP manager.
* This parameter is owned by the SNMP framework and must be
* considered as transient. If you wish to keep some of its
* content after this method returns (by storing it in the
* returned object for instance) you should clone that
* information.
*
* @return A newly allocated user-data contextual object, or
* null
* @exception SnmpStatusException If an SnmpStatusException is thrown,
* the request will be aborted.
*
* @since 1.5
**/
public Object allocateUserData(SnmpPdu requestPdu)
throws SnmpStatusException;
/**
* Called by the SnmpAdaptorServer
adaptor.
* Release a previously allocated contextual object containing user-data.
* This method is called just before the responsePdu is sent back to the
* manager. It gives the user a chance to alter the responsePdu packet
* before it is encoded, and to free any resources that might have
* been allocated when creating the contextual object.
*
* @param userData The contextual object being released.
* @param responsePdu The SnmpPduPacket that will be sent back to the
* SNMP manager.
* This parameter is owned by the SNMP framework and must be
* considered as transient. If you wish to keep some of its
* content after this method returns you should clone that
* information.
*
* @exception SnmpStatusException If an SnmpStatusException is thrown,
* the responsePdu is dropped and nothing is returned to
* to the manager.
*
* @since 1.5
**/
public void releaseUserData(Object userData, SnmpPdu responsePdu)
throws SnmpStatusException;
}