BasePersistenceUnitDependencyResolver.java

/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2008, 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.jpa.resolvers;

import org.jboss.beans.metadata.api.annotations.Inject;
import org.jboss.deployers.structure.spi.DeploymentUnit;
import org.jboss.jpa.javaee.JavaEEModuleInformer;
import org.jboss.jpa.resolvers.strategy.SearchStrategy;

/**
 * A configurable PersistenceUnitDependencyResolver.
 * 
 * @author <a href="mailto:cdewolf@redhat.com">Carlo de Wolf</a>
 * @version $Revision: $
 */
public abstract class BasePersistenceUnitDependencyResolver implements PersistenceUnitDependencyResolver
{
   private JavaEEModuleInformer javaEEModuleInformer;
   
   private SearchStrategy strategy;
   
   /**
    * Make sure to set the strategy before using!
    */
   protected BasePersistenceUnitDependencyResolver()
   {
      
   }
   
   protected BasePersistenceUnitDependencyResolver(SearchStrategy strategy)
   {
      assert strategy != null : "strategy is null";
      
      this.strategy = strategy;
   }
   
   public String createBeanName(DeploymentUnit deploymentUnit, String persistenceUnitName)
   {
      // persistenceUnitName must be a simple name
      assert persistenceUnitName.indexOf('/') == -1;
      assert persistenceUnitName.indexOf('#') == -1;
      
      String appName = javaEEModuleInformer.getApplicationName(deploymentUnit);
      String modulePath = javaEEModuleInformer.getModulePath(deploymentUnit);
      String unitName = (appName != null ? appName + "/" : "") + modulePath + "#" + persistenceUnitName;
      return "persistence.unit:unitName=" + unitName;
   }

   protected static DeploymentUnit getDeploymentUnit(DeploymentUnit current, String path)
   {
      if(path.startsWith("/"))
         return getDeploymentUnit(current.getTopLevel(), path.substring(1));
      if(path.startsWith("./"))
         return getDeploymentUnit(current, path.substring(2));
      if(path.startsWith("../"))
         return getDeploymentUnit(current.getParent(), path.substring(3));
      int i = path.indexOf('/');
      String name;
      if(i == -1)
         name = path;
      else
         name = path.substring(0, i);
      for(DeploymentUnit child : current.getChildren())
      {
         if(child.getSimpleName().equals(name))
            return child;
      }
      throw new IllegalArgumentException("Can't find a deployment unit named " + name + " at " + current);
   }
   
   public String resolvePersistenceUnitSupplier(DeploymentUnit deploymentUnit, String persistenceUnitName)
   {
      int i = (persistenceUnitName == null ? -1 : persistenceUnitName.indexOf('#'));
      if(i != -1)
      {
         String path = persistenceUnitName.substring(0, i);
         String unitName = persistenceUnitName.substring(i + 1);
         DeploymentUnit targetDeploymentUnit = getDeploymentUnit(deploymentUnit, path);
         // TODO: verify the existence of PersistenceUnitMetaData?
         return createBeanName(targetDeploymentUnit, unitName);
      }
      else
      {
         if(strategy == null)
            throw new IllegalStateException("No strategy was set on " + this);
         String name = strategy.findPersistenceUnitSupplier(this, deploymentUnit, persistenceUnitName);
         if(name == null)
            throw new IllegalArgumentException("Can't find a persistence unit named '" + persistenceUnitName + "' in " + deploymentUnit);
         return name;
      }
   }
   
   @Inject
   public void setJavaEEModuleInformer(JavaEEModuleInformer informer)
   {
      this.javaEEModuleInformer = informer;
   }
   
   protected void setSearchStrategy(SearchStrategy strategy)
   {
      assert strategy != null : "strategy is null";
      
      this.strategy = strategy;
   }
}