1 

     2 /*

     3  * Copyright (c) 2007-2008 Nokia Corporation and/or its subsidiary(-ies).

     4  * All rights reserved.

     5  * This component and the accompanying materials are made available

     6  * under the terms of the License "Eclipse Public License v1.0"

     7  * which accompanies this distribution, and is available

     8  * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     9  *

    10  * Initial Contributors:

    11  * Nokia Corporation - initial contribution.

    12  *

    13  * Contributors:

    14  *

    15  * Description:  

    16  *

    17  */

    18 

    19 package com.nokia.helium.jpa;

    20 

    21 import org.apache.log4j.Logger;

    22 import java.util.HashMap;

    23 import org.apache.tools.ant.BuildException;

    24 import java.io.IOException;

    25 

    26 /**

    27  * Utility class to communicate to the database using JPA entity

    28  * manager.

    29  */

    30 public final class ORMUtil {

    31 

    32     private static Logger log = Logger.getLogger(ORMUtil.class);

    33     

    34     private static final int PERSISTANCE_COUNT_LIMIT = 1000;

    35 

    36     private static final int READ_CACHE_LIMIT = 30000;

    37 

    38     private static HashMap<String, ORMEntityManager> emMap = 

    39         new HashMap<String, ORMEntityManager>();

    40 

    41     private static HashMap<String, Integer> emMapCount = 

    42         new HashMap<String, Integer>();

    43 

    44     private static Object mutexObject = new Object();

    45     private ORMUtil() {

    46     }

    47     

    48     /**

    49      * Initializes the entity manager and begins the transcations.

    50      * @param urlPath - database path to be connected to.

    51      */

    52     public static synchronized void initializeORM(String urlPath) {

    53         ORMEntityManager manager = emMap.get(urlPath);

    54         log.debug("initializeORM: urlpath: " + urlPath);

    55         if (manager == null) {

    56             try {

    57                 log.debug("initializing for the first time");

    58                 manager = new ORMEntityManager(urlPath);

    59                 emMap.put(urlPath, manager);

    60                 Integer countObj = new Integer(1);

    61                 emMapCount.put(urlPath, countObj);

    62                 log.debug("initializeORM: manager: " + manager);

    63                 log.debug("initializeORM: manager: " + manager.getEntityManager());

    64             } catch ( IOException ex ) {

    65                 throw new BuildException("Entity Manager creation failure");

    66             }

    67         } else {

    68             Integer countObj = emMapCount.get(urlPath);

    69             log.debug("object exists and incrementing the value");

    70             countObj = new Integer(countObj.intValue() + 1);

    71             log.debug("object exists count value: " + countObj.intValue());

    72             emMapCount.put(urlPath, countObj);

    73         }

    74     }

    75 

    76     /**

    77      * Helper Function to return the entity manager.

    78      * @return entity manager created during initialization.

    79      */

    80     public static synchronized ORMEntityManager getEntityManager(String urlPath) {

    81         log.debug("getEntityManager: urlpath: " + urlPath);

    82         ORMEntityManager manager = emMap.get(urlPath);

    83         if (manager != null) {

    84             log.debug("getEntityManager: manager: " + manager);

    85             log.debug("getEntityManager: manager.entityManager: " + manager.getEntityManager());

    86             return manager;

    87         } else {

    88             log.debug("getEntityManager: manager: is null");

    89             throw new BuildException("ORM entity manager is null");

    90         }

    91     }

    92     

    93     /**

    94      * Finalize the entity manager and release all the objects.

    95      */

    96     public static synchronized void finalizeORM(String urlPath) {

    97         ORMEntityManager manager = emMap.get(urlPath);

    98         log.debug("finalizeORM: urlpath: " + urlPath);

    99         if (manager != null) {

   100             Integer countObj = emMapCount.get(urlPath);

   101             if (countObj != null) {

   102                 int count = countObj.intValue();

   103                 count = count - 1;

   104                 if (count > 0) {

   105                     countObj = new Integer(count);

   106                     log.debug("countOBj value: " + countObj.intValue());

   107                     emMapCount.put(urlPath, countObj);

   108                 } else {

   109                     manager.finalizeEntityManager();

   110                     manager = null;

   111                     log.debug("finalizeORM: manager" + manager);

   112                     emMap.remove(urlPath);

   113                     emMapCount.remove(urlPath);

   114                 }

   115             }

   116         }

   117     }

   118     

   119     public static Object getMutexObject() {

   120         return mutexObject;

   121     }

   122 }