/*

  * Copyright 2001,2004 The Apache Software Foundation.

  * 

  * Licensed under the Apache 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.apache.org/licenses/LICENSE-2.0

  * 

  * 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.apache.commons.scaffold.sql;

 import java.sql.SQLException;

 import javax.servlet.http.HttpServlet;

 import javax.sql.DataSource;

 /**

  * Connection adaptor for a connection pool that is exposed

  * through the servlet context, like the Struts generic

  * connection pool.

  * <p>

  * The ConnectionServlet will automatically set a reference

  * to itself if an instance of this class is specified

  * as the ConnectionAdaptor.

  *

  * @author Ted Husted

  * @version $Revision: 155464 $ $Date: 2005-02-26 13:26:54 +0000 (Sat, 26 Feb 2005) $

  */

 public class ServletAdaptor extends ConnectionAdaptor {

     /**

      * Field to store a link to a servlet in the application.

      */

     private static HttpServlet servlet = null;

     /**

      * Set a reference to a servlet in the application

      * to allow access to the servlet context.

      */

     public void setServlet(HttpServlet servlet) {

         ServletAdaptor.servlet = servlet;

     }

    /**

     * Return datasource from the servlet context using

     * key as the attribute name.

     *

     * @param key The attribute name for the resource.

     * If null is passed, null is returned.

     * @returns null or the datasource object related to "key"

     */

     protected DataSource getDataSource(String key)

             throws SQLException {

         if (null==key) return null;

         return (DataSource)

             servlet.getServletContext().getAttribute(key);

     }

      // Required

     public ServletAdaptor() {

         if (null==pool) pool = this;

     }

 } // end ServletAdaptor