[jboss-cvs] JBossAS SVN: r71958 - projects/cluster/ha-server-api/trunk/src/main/java/org/jboss/ha/framework/server.

jboss-cvs-commits at lists.jboss.org jboss-cvs-commits at lists.jboss.org
Thu Apr 10 12:39:46 EDT 2008


Author: bstansberry at jboss.com
Date: 2008-04-10 12:39:45 -0400 (Thu, 10 Apr 2008)
New Revision: 71958

Added:
   projects/cluster/ha-server-api/trunk/src/main/java/org/jboss/ha/framework/server/HAPartitionLocator.java
Log:
[JBCLUSTER-192] Add a service locator utility class for HAPartition

Added: projects/cluster/ha-server-api/trunk/src/main/java/org/jboss/ha/framework/server/HAPartitionLocator.java
===================================================================
--- projects/cluster/ha-server-api/trunk/src/main/java/org/jboss/ha/framework/server/HAPartitionLocator.java	                        (rev 0)
+++ projects/cluster/ha-server-api/trunk/src/main/java/org/jboss/ha/framework/server/HAPartitionLocator.java	2008-04-10 16:39:45 UTC (rev 71958)
@@ -0,0 +1,190 @@
+/*
+ * JBoss, Home of Professional Open Source.
+ * Copyright 2006, Red Hat Middleware LLC, and individual contributors
+ * as indicated by the @author tags. See the copyright.txt file in the
+ * distribution for a full listing of individual contributors.
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this software; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
+ */
+
+package org.jboss.ha.framework.server;
+
+import java.util.Hashtable;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+import javax.naming.Context;
+import javax.naming.InitialContext;
+import javax.naming.NameNotFoundException;
+import javax.naming.NamingException;
+
+import org.jboss.ha.framework.interfaces.HAPartition;
+import org.jboss.logging.Logger;
+
+/**
+ * Service Locator utility for locating an {@link HAPartition}. Maintains
+ * an internal registry of partitions, and if it cannot find a partition there,
+ * will attempt to find it in JNDI using a standard naming pattern.
+ * 
+ * @author <a href="brian.stansberry at jboss.com">Brian Stansberry</a>
+ * @version $Revision: 1.1 $
+ */
+public class HAPartitionLocator
+{
+   private static final Logger log = Logger.getLogger(HAPartitionLocator.class);
+   
+   private static HAPartitionLocator sharedInstance = new HAPartitionLocator();
+   
+   /** Name of the standard JNDI context under which HAPartitions are bound */
+   public static final String JNDI_CONTEXT_NAME = "/HAPartition/";
+   
+   private Map<String, HAPartition> registeredPartitions = new ConcurrentHashMap<String, HAPartition>();
+   
+   /**
+    * Gets the 
+    * @return the shared HAPartitionLocator; will not be <code>null</code>
+    */
+   public static HAPartitionLocator getHAPartitionResolver()
+   {
+      return sharedInstance;
+   }
+   
+   /**
+    * Appends the partition name to {@link #JNDI_CONTEXT_NAME}; e.g.
+    * <code>/HAPartition/DefaultPartition</code>.
+    * 
+    * @param partitionName the name of the partition
+    * @return a string representing the standard name under which a 
+    *         partition is bound in JNDI.
+    */
+   public static final String getStandardJndiBinding(String partitionName)
+   {
+      return JNDI_CONTEXT_NAME + partitionName;
+   }
+   
+   /**
+    * Allows replacement of the default implementation.
+    * 
+    * @param shared the locator to use. Cannot be <code>null</code>.
+    */
+   protected static void setSharedInstance(HAPartitionLocator shared)
+   {
+      if (shared == null)
+         throw new IllegalArgumentException("shared cannot be null");
+      
+      sharedInstance = shared;
+   }
+   
+   /**
+    * Allow subclasses to create a new HAPartitionLocator.
+    */
+   protected HAPartitionLocator()
+   {      
+   }
+   
+   /**
+    * Locates and returns the {@link HAPartition} whose partition name matches
+    * the given <code>partitionName</code>.
+    * 
+    * @param partitionName  the name of the partition. Cannot be <code>null</code>.
+    * @param jndiProperties any naming properties to pass to new InitialContext() 
+    *                       if JNDI lookup is needed.
+    * @return the partition. Will not return <code>null</code>
+    * 
+    * @throws IllegalStateException if no matching partition can be found
+    */
+   public HAPartition getHAPartition(String partitionName, Hashtable jndiProperties)
+   {
+      HAPartition partition = findInRegistry(partitionName);
+      if (partition == null)
+      {
+         try
+         {
+            partition = findInJndi(partitionName, jndiProperties);
+         }
+         catch (NamingException e)
+         {
+            log.error("Problem finding partition " + partitionName + " in JNDI", e);        
+         }
+      }
+      
+      if (partition == null)
+         throw new IllegalStateException("Partition " + partitionName + " not found");
+      
+      return partition;
+   }
+   
+   /**
+    * Register a partition with this locator.
+    * 
+    * @param partition the partition
+    */
+   public void registerHAPartition(HAPartition partition)
+   {
+      if (partition != null)
+         registeredPartitions.put(partition.getPartitionName(), partition);
+   }
+   
+   /**
+    * Deregister a partition from this locator.
+    * 
+    * @param partition the partition
+    */
+   public void deregisterHAPartition(HAPartition partition)
+   {
+      if (partition != null)
+         registeredPartitions.remove(partition.getPartitionName());
+   }
+   
+   /**
+    * Find the given partition in the local registry.
+    * 
+    * @param partitionName the name of the partition. Cannot be <code>null</code>.
+    * @return the partition, or <code>null</code>
+    */
+   protected HAPartition findInRegistry(String partitionName)
+   {
+      return registeredPartitions.get(partitionName);
+   }
+   
+   /**
+    * Find the given partition in JNDI under a 
+    * {@link #getStandardJndiBinding(String) standard binding}.
+    * 
+    * @param partitionName the name of the partition. Cannot be <code>null</code>.
+    * @return the partition, or <code>null</code>
+    * 
+    * @throws NamingException if there is a problem with the naming context. Will
+    *                         not throw NameNotFoundException; if not found, will
+    *                         return <code>null</code>.
+    *                         
+    * @see #getStandardJndiBinding(String)
+    */
+   protected HAPartition findInJndi(String partitionName, Hashtable jndiProperties) throws NamingException
+   {
+      try
+      {
+         Context ctx = new InitialContext(jndiProperties);
+         return (HAPartition) ctx.lookup(getStandardJndiBinding(partitionName));
+      }
+      catch (NameNotFoundException e)
+      {
+         // just not there
+         return null;
+      }     
+      
+   }
+}




More information about the jboss-cvs-commits mailing list