BaseSearchStrategy.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.strategy;

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.PersistenceUnitDependencyResolver;
import org.jboss.metadata.jpa.spec.PersistenceMetaData;
import org.jboss.metadata.jpa.spec.PersistenceUnitMetaData;

/**
 * The spec compliant persistence unit search stragegy.
 * 
 * To allow injection by class it has a base name.
 * 
 * See EJB 3.0 6.2.2.
 * 
 * @author <a href="mailto:cdewolf@redhat.com">Carlo de Wolf</a>
 * @version $Revision: $
 */
public abstract class BaseSearchStrategy implements SearchStrategy
{
   private JavaEEModuleInformer javaEEModuleInformer;
   
   public String findPersistenceUnitSupplier(PersistenceUnitDependencyResolver resolver, DeploymentUnit deploymentUnit, String persistenceUnitName)
   {
      String name = findWithinModule(resolver, deploymentUnit, persistenceUnitName, true);
      if(name == null)
         name = findWithinApplication(resolver, deploymentUnit.getTopLevel(), persistenceUnitName);
      return name;
   }
   
   protected String findWithinApplication(PersistenceUnitDependencyResolver resolver, DeploymentUnit unit, String persistenceUnitName)
   {
      String name = findWithinModule(resolver, unit, persistenceUnitName, false);
      if(name != null)
         return name;
      
      for(DeploymentUnit child : unit.getChildren())
      {
         name = findWithinApplication(resolver, child, persistenceUnitName);
         if(name != null)
            return name;
      }
      return null;
   }
   
   /*
    * When finding the default persistence unit, the first persistence unit encountered is returned.
    * TODO: Maybe the name of unscoped persistence units should be changed, so only one can be deployed anyway.
    */
   protected String findWithinModule(PersistenceUnitDependencyResolver resolver, DeploymentUnit unit, String persistenceUnitName, boolean allowScoped)
   {
      if(!allowScoped && isScoped(unit))
         return null;
      
      PersistenceMetaData persistenceMetaData = unit.getAttachment(PersistenceMetaData.class);
      if(persistenceMetaData == null)
         return null;
      for(PersistenceUnitMetaData persistenceUnit : persistenceMetaData.getPersistenceUnits())
      {
         if(persistenceUnitName == null || persistenceUnitName.length() == 0 || persistenceUnit.getName().equals(persistenceUnitName))
            return resolver.createBeanName(unit, persistenceUnit.getName());
      }
      return null;
   }
   
   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);
   }
   
   /*
    * EJB3 JPA 6.2.2: Persistence Unit Scope
    */
   private boolean isScoped(DeploymentUnit unit)
   {
      JavaEEModuleInformer.ModuleType type = javaEEModuleInformer.getModuleType(unit);
      if(type == JavaEEModuleInformer.ModuleType.APP_CLIENT)
         return true;
      if(type == JavaEEModuleInformer.ModuleType.EJB)
         return true;
      if(type == JavaEEModuleInformer.ModuleType.WEB)
         return true;
      return false;
   }
   
   @Inject
   public void setJavaEEModuleInformer(JavaEEModuleInformer informer)
   {
      this.javaEEModuleInformer = informer;
   }
}