/*

  * Copyright 2007-2008 The Kuali Foundation

  *

  * Licensed under the Educational Community License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  *

  * http://www.opensource.org/licenses/ecl2.php

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package org.kuali.rice.core.resourceloader;

 import javax.xml.namespace.QName;

 import org.kuali.rice.core.config.ConfigurationException;

 import org.kuali.rice.core.resourceloader.ResourceLoader;

 import org.springframework.beans.factory.BeanNameAware;

 import org.springframework.beans.factory.FactoryBean;

 import org.springframework.beans.factory.InitializingBean;

 /**

  * Exports services in the {@link GlobalResourceLoader} as beans available to Spring.

  * 

  * @author Kuali Rice Team (rice.collab@kuali.org)

  */

 public class ResourceLoaderServiceFactoryBean implements BeanNameAware, FactoryBean, InitializingBean {

     /**

      * The service to retrieve.  If unset, defaults to bean name.

      */

     private String serviceName;

     /**

      * The KSB namespace in which to look for the service, default is null, which is 'local' services

      */

     private String namespace;

     /**

      * Whether we provide a singleton.  Since we cannot make that guarantee, the default is 'false'

      */

     private boolean singleton;

     /**

      * The resource loader in which to look up the service

      */

     private ResourceLoader resourceLoader;

     /**

      * @return the configured service name

      */

     public String getServiceName() {

         return serviceName;

     }

     /**

      * @param serviceName the service name to retrieve from the ResourceLoader

      */

     public void setServiceName(String serviceName) {

         this.serviceName = serviceName;

     }

     /**

      * @return the namespace under which to look up the service/bean

      */

     public String getNamespace() {

         return namespace;

     }

     /**

      * @param namespace the namespace under which to look up the service/bean

      */

     public void setNamespace(String namespace) {

         this.namespace = namespace;

     }

     /**

      * @param singleton whether we know that the target bean will be a singleton

      */

     public void setSingleton(boolean singleton) {

         this.singleton = singleton;

     }

     /**

      * @see org.springframework.beans.factory.FactoryBean#isSingleton()

      */

     public boolean isSingleton() {

         return singleton;

     }

     /**

      * @param resourceLoader the ResourceLoader in which to look up the service

      */

     public void setResourceLoader(ResourceLoader resourceLoader) {

         this.resourceLoader = resourceLoader;

     }

     /**

      * @return the ResourceLoader with which this factory bean has been configured

      */

     public ResourceLoader getResourceLoader() {

         return resourceLoader;

     }

     /**

      * @see org.springframework.beans.factory.BeanNameAware#setBeanName(java.lang.String)

      */

     public void setBeanName(String name) {

         // by default the service name is just the bean name

         this.serviceName = name;

     }

     public void afterPropertiesSet() throws Exception {

         if (this.getServiceName() == null) {

             throw new ConfigurationException("No serviceName given.");

         }

         if (this.resourceLoader == null) {

             this.resourceLoader = GlobalResourceLoader.getResourceLoader();

         }

     }

     /**

      * Constructs a QName from the defined namespace and beanName

      * @param beanName the bean name to look up

      * @return a QName with beanName qualified with namespace

      */

     protected QName getQName(String beanName) {

         return new QName(namespace, beanName);

     }

     /**

      * @see org.springframework.beans.factory.FactoryBean#getObject()

      */

     public Object getObject() throws Exception {

         return resourceLoader.getService(getQName(this.getServiceName()));

     }

     /**

      * @see org.springframework.beans.factory.FactoryBean#getObjectType()

      */

     public Class getObjectType() {

         // we cannot know the type before lookup, so return null as per contract

         return null;

     }

 }