1 /*

     2  * Copyright (c) 2003, 2006, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 package sun.management.snmp.util;

    26 

    27 import com.sun.jmx.mbeanserver.Util;

    28 import com.sun.jmx.snmp.agent.SnmpUserDataFactory;

    29 import com.sun.jmx.snmp.SnmpPdu;

    30 import com.sun.jmx.snmp.SnmpStatusException;

    31 

    32 import java.util.Collections;

    33 import java.util.HashMap;

    34 import java.util.Map;

    35 

    36 

    37 public class JvmContextFactory implements SnmpUserDataFactory {

    38 

    39     /**

    40      * Called by the <CODE>SnmpAdaptorServer</CODE> adaptor.

    41      * Allocate a contextual object containing some user data. This method

    42      * is called once for each incoming SNMP request. The scope

    43      * of this object will be the whole request. Since the request can be

    44      * handled in several threads, the user should make sure that this

    45      * object can be accessed in a thread-safe manner. The SNMP framework

    46      * will never access this object directly - it will simply pass

    47      * it to the <code>SnmpMibAgent</code> within

    48      * <code>SnmpMibRequest</code> objects - from where it can be retrieved

    49      * through the {@link com.sun.jmx.snmp.agent.SnmpMibRequest#getUserData() getUserData()} accessor.

    50      * <code>null</code> is considered to be a valid return value.

    51      *

    52      * This method is called just after the SnmpPduPacket has been

    53      * decoded.

    54      *

    55      * @param requestPdu The SnmpPduPacket received from the SNMP manager.

    56      *        <b>This parameter is owned by the SNMP framework and must be

    57      *        considered as transient.</b> If you wish to keep some of its

    58      *        content after this method returns (by storing it in the

    59      *        returned object for instance) you should clone that

    60      *        information.

    61      *

    62      * @return A newly allocated user-data contextual object, or

    63      *         <code>null</code>

    64      * @exception SnmpStatusException If an SnmpStatusException is thrown,

    65      *            the request will be aborted.

    66      *

    67      * @since Java DMK 5.0

    68      **/

    69     public Object allocateUserData(SnmpPdu requestPdu)

    70         throws SnmpStatusException {

    71         return Collections.synchronizedMap(new HashMap<Object, Object>());

    72     }

    73 

    74     /**

    75      * Called by the <CODE>SnmpAdaptorServer</CODE> adaptor.

    76      * Release a previously allocated contextual object containing user-data.

    77      * This method is called just before the responsePdu is sent back to the

    78      * manager. It gives the user a chance to alter the responsePdu packet

    79      * before it is encoded, and to free any resources that might have

    80      * been allocated when creating the contextual object.

    81      *

    82      * @param userData The contextual object being released.

    83      * @param responsePdu The SnmpPduPacket that will be sent back to the

    84      *        SNMP manager.

    85      *        <b>This parameter is owned by the SNMP framework and must be

    86      *        considered as transient.</b> If you wish to keep some of its

    87      *        content after this method returns you should clone that

    88      *        information.

    89      *

    90      * @exception SnmpStatusException If an SnmpStatusException is thrown,

    91      *            the responsePdu is dropped and nothing is returned to

    92      *            to the manager.

    93      *

    94      * @since Java DMK 5.0

    95      **/

    96     public void releaseUserData(Object userData, SnmpPdu responsePdu)

    97         throws SnmpStatusException {

    98         ((Map<?, ?>)userData).clear();

    99     }

   100 

   101 

   102     public static Map<Object, Object> getUserData() {

   103         final Object userData =

   104             com.sun.jmx.snmp.ThreadContext.get("SnmpUserData");

   105 

   106         if (userData instanceof Map<?, ?>) return Util.cast(userData);

   107         else return null;

   108     }

   109 

   110 }