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 }