001    /* ObjectHolder.java --
002       Copyright (C) 2005, 2006 Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    
039    package org.omg.CORBA;
040    
041    import gnu.CORBA.typecodes.RecordTypeCode;
042    
043    import org.omg.CORBA.portable.InputStream;
044    import org.omg.CORBA.portable.OutputStream;
045    import org.omg.CORBA.portable.Streamable;
046    
047    /**
048     * A holder for CORBA <code>Object</code> that is mapped into
049     * java <code>org.omg.CORBA.Object</code>.
050     *
051     * The holders have several application areas. The end user usually
052     * sees them implementing CORBA methods where the primitive type
053     * is passed by reference. While CORBA (or, for example, C) supports
054     * this, the java does not and a wrapper class is required.
055     *
056     * @author Audrius Meskauskas (AudriusA@Bioinformatics.org)
057     */
058    public final class ObjectHolder
059      implements Streamable
060    {
061      /**
062       * The default type code for this holder if the object type code with
063       * the zero length string as id.
064       */
065      private static final RecordTypeCode t_object;
066    
067      static
068      {
069        t_object = new RecordTypeCode(TCKind.tk_objref);
070        t_object.setId("");
071      }
072    
073      /**
074       * The <code>org.omg.CORBA.Object</code> (CORBA <code>Object</code>) value,
075       * held by this ObjectHolder.
076       */
077      public org.omg.CORBA.Object value;
078    
079      /**
080       * Constructs an instance of ObjectHolder,
081       * initializing {@link #value} to <code>0</code>.
082       */
083      public ObjectHolder()
084      {
085      }
086    
087      /**
088       * Constructs an instance of ObjectHolder,
089       * initializing {@link #value} to the given <code>org.omg.CORBA.Object</code>.
090       *
091       * @param initial_value a value that will be assigned to the
092       * {@link #value} field.
093       */
094      public ObjectHolder(org.omg.CORBA.Object initial_value)
095      {
096        value = initial_value;
097      }
098    
099      /**
100       * Fill in the {@link #value } field by reading the required data
101       * from the given stream. For <code>org.omg.CORBA.Object</code>, the
102       * functionality is delegated to
103       * {@link org.omg.CORBA.portable.InputStream#read_Object()}.
104       *
105       * @param input the input stream to read from.
106       */
107      public void _read(InputStream input)
108      {
109        value = input.read_Object();
110      }
111    
112      /**
113       * Returns the TypeCode, corresponding the CORBA type that is stored
114       * using this holder.
115       */
116      public TypeCode _type()
117      {
118        return ObjectHelper.type();
119      }
120    
121      /**
122       * Write the {@link #value } field to the given stream.
123       * For <code>Object</code>, the functionality
124       * is delegated to
125       * {@link org.omg.CORBA.portable.OutputStream#write_Object(Object) }.
126       *
127       * @param output the output stream to write into.
128       */
129      public void _write(OutputStream output)
130      {
131        output.write_Object(value);
132      }
133    }