001/* ValueHandler.java --
002   Copyright (C) 2002, 2004, 2005 Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038
039package javax.rmi.CORBA;
040
041import java.io.Serializable;
042
043import org.omg.CORBA.CustomMarshal;
044import org.omg.CORBA.portable.InputStream;
045import org.omg.CORBA.portable.OutputStream;
046import org.omg.CORBA.portable.Streamable;
047import org.omg.SendingContext.RunTime;
048
049/**
050 * Serializes Java objects to and from CDR (GIOP) streams. The working instance
051 * of the value handler is returned by {@link Util#createValueHandler} and can
052 * be altered by setting the system property "javax.rmi.CORBA.ValueHandlerClass"
053 * to the name of the alternative class that must implement ValueHandler.
054 * 
055 * @author Audrius Meskauskas (AudriusA@Bioinformatics.org)
056 */
057public interface ValueHandler
058{
059  /**
060   * Get CORBA repository Id for the given java class.
061   * 
062   * The syntax of the repository ID is the initial ?RMI:?, followed by the Java
063   * class name, followed by name, followed by a hash code string, followed
064   * optionally by a serialization version UID string.
065   * 
066   * For Java identifiers that contain illegal OMG IDL identifier characters
067   * such as ?$?, any such illegal characters are replaced by ?\U? followed by
068   * the 4 hexadecimal characters (in upper case) representing the Unicode
069   * value.
070   * 
071   * @param clz a class for that the repository Id is required.
072   * 
073   * @return the class repository id.
074   */
075  String getRMIRepositoryID(Class clz);
076
077  /**
078   * Returns the CodeBase for this ValueHandler.
079   * 
080   * @return the codebase.
081   */
082  RunTime getRunTimeCodeBase();
083
084  /**
085   * Indicates that the given class is responsible itself for writing its
086   * content to the stream. Such classes implement either {@link Streamable}
087   * (default marshalling, generated by IDL-to-java compiler) or
088   * {@link CustomMarshal} (the user-programmed marshalling).
089   * 
090   * @param clz the class being checked.
091   * @return true if the class supports custom or default marshalling, false
092   * otherwise.
093   */
094  boolean isCustomMarshaled(Class clz);
095
096  /**
097   * Read value from the CORBA input stream in the case when the value is not
098   * Streamable or CustomMarshall'ed. The fields of the class being written will
099   * be accessed using reflection.
100   * 
101   * @param in a CORBA stream to read.
102   * @param offset the current position in the input stream.
103   * @param clz the type of value being read.
104   * @param repositoryID the repository Id of the value being read.
105   * @param sender the sending context that should provide data about the
106   * message originator.
107   * 
108   * @return the object, extracted from the stream.
109   */
110  Serializable readValue(InputStream in, int offset, Class clz,
111    String repositoryID, RunTime sender);
112
113  /**
114   * When the value provides the writeReplace method, the result of this method
115   * is written. Otherwise, the value itself is written.
116   * 
117   * @param value the value that should be written to the stream.
118   * 
119   * @return the value that will be actually written to the stream.
120   */
121  Serializable writeReplace(Serializable value);
122
123  /**
124   * Write value to CORBA output stream using java senmatics.
125   * 
126   * @param out a stream to write into.
127   * @param value a java object to write.
128   */
129  void writeValue(OutputStream out, Serializable value);
130}