/*

  * $Source$

  * $Revision$

  *

  * Copyright (C) 2000 William Chesters

  *

  * Part of Melati (http://melati.org), a framework for the rapid

  * development of clean, maintainable web applications.

  *

  * Melati is free software; Permission is granted to copy, distribute

  * and/or modify this software under the terms either:

  *

  * a) the GNU General Public License as published by the Free Software

  *    Foundation; either version 2 of the License, or (at your option)

  *    any later version,

  *

  *    or

  *

  * b) any version of the Melati Software License, as published

  *    at http://melati.org

  *

  * You should have received a copy of the GNU General Public License and

  * the Melati Software License along with this program;

  * if not, write to the Free Software Foundation, Inc.,

  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the

  * GNU General Public License and visit http://melati.org to obtain the

  * Melati Software License.

  *

  * Feel free to contact the Developers of Melati (http://melati.org),

  * if you would like to work out a different arrangement than the options

  * outlined here.  It is our intention to allow Melati to be used by as

  * wide an audience as possible.

  *

  * This program 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 General Public License for more details.

  *

  * Contact details for copyright holder:

  *

  *     William Chesters <williamc At paneris.org>

  *     http://paneris.org/~williamc

  *     Obrechtstraat 114, 2517VX Den Haag, The Netherlands

  */

 package org.melati.poem.transaction;

 import java.util.Vector;

 import java.util.Enumeration;

 import java.io.OutputStream;

 import java.io.InputStream;

 import java.io.Reader;

 import java.io.Writer;

 import java.sql.SQLException;

 import java.sql.Statement;

 import java.sql.ResultSet;

 import org.melati.poem.PoemBugPoemException;

 /**

  * List of objects which need closing when a <code>Transaction</code> is

  * terminated.

  */

 public class ToTidyList {

   /** Can be closed. */

   public interface Closeable {

     /**

      * Free any resources and prepare for death or reuse.

      */

     void close();

   }

   private Vector<Object> objects = new Vector<Object>();

   private static void tidy(Object o) {

     try {

       if (o instanceof ResultSet) 

         try { 

           ((ResultSet)o).close();

         } catch (SQLException e) {

           // HACK MSAccess not playing nice

           if (!e.getMessage().equals("ResultSet is closed"))

             throw e;

         }

       else if (o instanceof Statement)

         ((Statement)o).close();

       else if (o instanceof Reader)

         ((Reader)o).close();

       else if (o instanceof Writer)

         ((Writer)o).close();

       else if (o instanceof InputStream)

         ((InputStream)o).close();

       else if (o instanceof OutputStream)

         ((OutputStream)o).close();

       else if (o instanceof Closeable)

         ((Closeable)o).close();

     } catch (Exception e) {

       throw new PoemBugPoemException("Unexpected object type in ToTidy: " + o.getClass(), e);

     }

   }

   /**

    * Close all objects on list.

    */

   public synchronized void close() {

     for (int i = objects.size() - 1; i >= 0; --i)

       tidy(objects.elementAt(i));

     objects.setSize(0);

   }

   private void addObject(Object o) {

     objects.addElement(o);

   }

   /**

    * Add a ResultSet to the list.

    * @param o the ResultSet to add

    */

   public void add(ResultSet o) {

     addObject(o);

   }

   /**

    * Add a Statement to the list.

    * @param o the Statement to add

    */

   public void add(Statement o) {

     addObject(o);

   }

   /**

    * Add a Reader to the list.

    * @param o the Reader to add

    */

   public void add(Reader o) {

     addObject(o);

   }

   /**

    * Add a Writer to the list.

    * @param o the Writer to add

    */

   public void add(Writer o) {

     addObject(o);

   }

   /**

    * Add an InputStream to the list.

    * @param o the InputStream to add

    */

   public void add(InputStream o) {

     addObject(o);

   }

   /**

    * Add an OutputStream to the list.

    * @param o the OutputStream to add

    */

   public void add(OutputStream o) {

     addObject(o);

   }

   /**

    * Add any Closeable to the list.

    * @param o the Closeable to add

    */

   public void add(Closeable o) {

     addObject(o);

   }

   /**

    * @return an Enumeration of the items on the list

    */

   public Enumeration<Object> elements() {

     return objects.elements();

   }

 }