libjava/classpath/gnu/java/beans/encoder/CollectionPersistenceDelegate.java

   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 }