Source for gnu.java.beans.encoder.CollectionPersistenceDelegate

   1: /* CollectionPersistenceDelegate.java - A PersistenceDelegate for Collection subclasses.
   2:  Copyright (C) 2005 Free Software Foundation, Inc.
   3: 
   4:  This file is part of GNU Classpath.
   5: 
   6:  GNU Classpath is free software; you can redistribute it and/or modify
   7:  it under the terms of the GNU General Public License as published by
   8:  the Free Software Foundation; either version 2, or (at your option)
   9:  any later version.
  10: 
  11:  GNU Classpath is distributed in the hope that it will be useful, but
  12:  WITHOUT ANY WARRANTY; without even the implied warranty of
  13:  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14:  General Public License for more details.
  15: 
  16:  You should have received a copy of the GNU General Public License
  17:  along with GNU Classpath; see the file COPYING.  If not, write to the
  18:  Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19:  02110-1301 USA.
  20: 
  21:  Linking this library statically or dynamically with other modules is
  22:  making a combined work based on this library.  Thus, the terms and
  23:  conditions of the GNU General Public License cover the whole
  24:  combination.
  25: 
  26:  As a special exception, the copyright holders of this library give you
  27:  permission to link this library with independent modules to produce an
  28:  executable, regardless of the license terms of these independent
  29:  modules, and to copy and distribute the resulting executable under
  30:  terms of your choice, provided that you also meet, for each linked
  31:  independent module, the terms and conditions of the license of that
  32:  module.  An independent module is a module which is not derived from
  33:  or based on this library.  If you modify this library, you may extend
  34:  this exception to your version of the library, but you are not
  35:  obligated to do so.  If you do not wish to do so, delete this
  36:  exception statement from your version. */
  37: 
  38: 
  39: package gnu.java.beans.encoder;
  40: 
  41: import java.util.Collection;
  42: import java.beans.Encoder;
  43: import java.beans.Expression;
  44: import java.beans.PersistenceDelegate;
  45: import java.beans.Statement;
  46: 
  47: import java.util.Iterator;
  48: 
  49: /** <p>A <code>PersistenceDelegate</code> implementation that calls
  50:  * the no-argument constructor to create the Collection instance and
  51:  * uses an iterator to add all the objects it reaches through it.</p>
  52:  *
  53:  * <p>It is used for <code>Set</code> and <code>List</code>
  54:  * implementations.</p>
  55:  *
  56:  * @author Robert Schuster (robertschuster@fsfe.org)
  57:  */
  58: public class CollectionPersistenceDelegate extends PersistenceDelegate
  59: {
  60: 
  61:   protected Expression instantiate(Object oldInstance, Encoder out)
  62:   {
  63:     return new Expression(
  64:                           oldInstance,
  65:                           oldInstance.getClass(),
  66:                           "new",
  67:                           null);
  68:   }
  69: 
  70:   protected void initialize(Class type, Object oldInstance, Object newInstance,
  71:                             Encoder out)
  72:   {
  73:     Iterator ite = ((Collection) oldInstance).iterator();
  74: 
  75:     while (ite.hasNext())
  76:       {
  77:         out.writeStatement(new Statement(oldInstance, "add",
  78:                                          new Object[] { ite.next() }));
  79: 
  80:       }
  81: 
  82:   }
  83: 
  84: }