001 /* InputStream.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_2_3.portable;
040
041 import gnu.CORBA.CDR.Vio;
042
043 import org.omg.CORBA.CustomMarshal;
044 import org.omg.CORBA.portable.BoxedValueHelper;
045 import org.omg.CORBA.portable.StreamableValue;
046
047 import java.io.Serializable;
048
049 /**
050 * This class defines a new CDR input stream methods, added since
051 * CORBA 2.3.
052 *
053 * This class is abstract; no direct instances can be instantiated.
054 * Also, up till v 1.4 inclusive there are no methods that would
055 * return it, and only one unimplemented interface,
056 * {@link org.omg.CORBA.portable.ValueFactory }, needs it as a parameter.
057 *
058 * However since 1.3 all methods, declared as returning an
059 * org.omg.CORBA.portable.InputStream actually return the instance of this
060 * derived class and the new methods are accessible after the casting
061 * operation.
062 *
063 * @author Audrius Meskauskas, Lithuania (AudriusA@Bioinformatics.org)
064 */
065 public abstract class InputStream
066 extends org.omg.CORBA.portable.InputStream
067 {
068 /**
069 * Read the abstract interface. An abstract interface can be either
070 * CORBA value type or CORBA object and is returned as an abstract
071 * java.lang.Object.
072 *
073 * As specified in OMG specification, this reads a single
074 * boolean and then delegates either to {@link #read_Object()} (for false)
075 * or to {@link #read_value()} (for true).
076 *
077 * @return an abstract interface, unmarshaled from the stream.
078 */
079 public Object read_abstract_interface()
080 {
081 boolean isObject = read_boolean();
082
083 if (isObject)
084 return read_Object();
085 else
086 return read_value();
087 }
088
089 /**
090 * Read the abstract interface, corresponding to the passed type.
091 * An abstract interface can be either CORBA value type or CORBA
092 * object and is returned as an abstract java.lang.Object.
093 *
094 * As specified in OMG specification, this reads a single
095 * boolean and then delegates either to {@link #read_Object(Class)} (for false)
096 * or to {@link #read_value(Class)} (for true).
097 *
098 * @param clz a base class for the abstract interface.
099 *
100 * @return an abstract interface, unmarshaled from the stream
101 */
102 public Object read_abstract_interface(Class clz)
103 {
104 boolean isValue = read_boolean();
105
106 if (isValue)
107 return read_value(clz);
108 else
109 return read_Object(clz);
110 }
111
112 /**
113 * Read a value type structure, extracting the repository id
114 * from the input stream itself. The repository id is optional
115 * in the value type record, but it must be present for this
116 * method to succeed. The {@link OutputStream} of this
117 * implementation always stores the repository id.
118 *
119 * The casts the streams ORB into a CORBA 2.3 ORB and then
120 * searched for a suitable value factory, where it delegates
121 * the functionality.
122 *
123 * If you know the exact class or can create an unitialised instance
124 * of the value type, it is recommended (faster) to use
125 * {@link #read_value(Class)} or {@link #read_value(Serializable)}
126 * instead.
127 *
128 * @return an value type structure, unmarshaled from the stream
129 */
130 public Serializable read_value()
131 {
132 return Vio.read(this);
133 }
134
135 /**
136 * Read a value type structure, corresponing to the passed type.
137 * As the type is known, the repository Id in the input stream is
138 * optional an not required. The codebase, if present, is also ignored.
139 *
140 * The passed class must implement either {@link CustomMarshal}
141 * for the user-defined reading operations or {@link StreamableValue}
142 * for the standard (generated by IDL compiler) reading operations.
143 * Also, it must have the parameterless constructor to create a new
144 * instance.
145 *
146 * @param clz a base class for a value type.
147 *
148 * @return an value type structure, unmarshaled from the stream
149 */
150 public Serializable read_value(Class clz)
151 {
152 return Vio.read(this, clz);
153 }
154
155 /**
156 * Read a value type structure content, when the unitialised
157 * instance is passed as a parameter. It is a fastest method to read
158 * a value type.
159 *
160 * As the type is known, the repository Id in the input stream is
161 * optional an not required. The codebase, if present, is also ignored.
162 *
163 * The passed instance must implement either {@link CustomMarshal}
164 * for the user-defined reading operations or {@link StreamableValue}
165 * for the standard (generated by IDL compiler) reading operations.
166 *
167 * @param unitialised_value the unitialised value.
168 *
169 * @return same value, filled in by the stream content.
170 */
171 public Serializable read_value(Serializable unitialised_value)
172 {
173 return (Serializable) Vio.read(this, unitialised_value, null);
174 }
175
176 /**
177 * Read a value type structure, having the given repository id.
178 * The casts the streams ORB into a CORBA 2.3 ORB and then
179 * searched for a suitable value factory, where it delegates
180 * the functionality.
181 *
182 * If you know the exact class or can create an unitialised instance
183 * of the value type, it is recommended (faster) to use
184 * {@link #read_value(Class)} or {@link #read_value(Serializable)}
185 * instead.
186 *
187 * @param repository_id a repository id of the value type.
188 *
189 * @return an value type structure, unmarshaled from the stream
190 */
191 public Serializable read_value(String repository_id)
192 {
193 return Vio.read(this, repository_id);
194 }
195
196 /**
197 * Use the provided boxed value helper to read the value.
198 *
199 * @param helper a helper for reading the value from the stream.
200 *
201 * @return an value type structure, unmarshaled from the stream.
202 */
203 public Serializable read_value(BoxedValueHelper helper)
204 {
205 return Vio.read(this, helper);
206 }
207 }