Improved cleanup of database resources when web application is unloaded

git-svn-id: http://scm.dspace.org/svn/repo/branches/dspace-1_5_x@2926 9c30dcfa-912a-0410-8fc2-9e0234be79fd

dspace-api/src/main/java/org/dspace/app/util/DSpaceContextListener.java

@@ -0,0 +1,99 @@
+/*
+ * DSpaceContextListener.java
+ *
+ * Version: $Revision: 1.3 $
+ *
+ * Date: $Date: 2006/07/05 21:39:29 $
+ *
+ * Copyright (c) 2002-2005, Hewlett-Packard Company and Massachusetts
+ * Institute of Technology.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * - Neither the name of the Hewlett-Packard Company nor the name of the
+ * Massachusetts Institute of Technology nor the names of their
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
+ * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
+ * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ */
+
+package org.dspace.app.util;
+
+import org.dspace.storage.rdbms.DatabaseManager;
+import org.apache.log4j.Logger;
+
+import javax.servlet.ServletContextListener;
+import javax.servlet.ServletContextEvent;
+import java.beans.Introspector;
+import java.sql.Driver;
+import java.sql.DriverManager;
+import java.util.Enumeration;
+
+/**
+ * Class to initialise / cleanup resources used by DSpace when the web application
+ * is started or stopped
+ */
+public class DSpaceContextListener implements ServletContextListener
+{
+    private static Logger log = Logger.getLogger(DSpaceContextListener.class);
+
+    /**
+     * Initialise any resources required by the application
+     * @param event
+     */
+    public void contextInitialized(ServletContextEvent event)
+    {
+    }
+
+    /**
+     * Clean up resources used by the application when stopped
+     * 
+     * @param event
+     */
+    public void contextDestroyed(ServletContextEvent event)
+    {
+        try
+        {
+            // Remove the database pool
+            DatabaseManager.shutdown();
+
+            // Clean out the introspector
+            Introspector.flushCaches();
+
+            // Remove any drivers registered by this classloader
+            for (Enumeration e = DriverManager.getDrivers(); e.hasMoreElements();)
+            {
+                Driver driver = (Driver) e.nextElement();
+                if (driver.getClass().getClassLoader() == getClass().getClassLoader())
+                {
+                    DriverManager.deregisterDriver(driver);
+                }
+            }
+        }
+        catch (Throwable e)
+        {
+            log.error("Failled to cleanup ClassLoader for webapp", e);
+        }
+    }
+}

dspace-api/src/main/java/org/dspace/storage/rdbms/DatabaseManager.java

@@ -1429,10 +1429,8 @@ public class DatabaseManager
         try
         {
             // Register basic JDBC driver
-            Class driverClass = Class.forName(ConfigurationManager
-                    .getProperty("db.driver"));
-            Driver basicDriver = (Driver) driverClass.newInstance();
-            DriverManager.registerDriver(basicDriver);
+            Class.forName(ConfigurationManager.getProperty("db.driver"));
+            Class.forName("org.apache.commons.dbcp.PoolingDriver");
 
             // Read pool configuration parameter or use defaults
             // Note we check to see if property is null; getIntProperty returns
@@ -1459,7 +1457,7 @@ public class DatabaseManager
             {
                 maxIdle = -1;
             }
-            
+
             boolean useStatementPool = ConfigurationManager.getBooleanProperty("db.statementpool",true);
 
             // Create object pool
@@ -1529,14 +1527,15 @@ public class DatabaseManager
             }
 
             //
-            // Finally, we create the PoolingDriver itself...
+            // Finally, we get the PoolingDriver itself...
             //
-            PoolingDriver driver = new PoolingDriver();
+            PoolingDriver driver = (PoolingDriver)DriverManager.getDriver("jdbc:apache:commons:dbcp:");
 
             //
             // ...and register our pool with it.
             //
-            driver.registerPool(poolName, connectionPool);
+            if (driver != null)
+                driver.registerPool(poolName, connectionPool);
 
             // Old SimplePool init
             //DriverManager.registerDriver(new SimplePool());