001/* ValueHandlerMultiFormat.java --
002   Copyright (C) 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 org.omg.CORBA.portable.OutputStream;
042
043import java.io.Serializable;
044
045/**
046 * This interface extends the previous ValueHandler, supporting various stream
047 * format versions. The {@link ValueHandler} can be casted into this interface
048 * to access additional features.
049 *
050 * @since 1.5
051 *
052 * @author Audrius Meskauskas, Lithuania (AudriusA@Bioinformatics.org)
053 */
054public interface ValueHandlerMultiFormat
055  extends ValueHandler
056{
057  /**
058   * Get the maximal supported version for the value types, supported by
059   * this value handler. The versions are integer numbers, the currently valid
060   * values being 1 and 2.
061   *
062   * These two versions differ in how the additional data, stored by the
063   * writeObject method, are encoded.
064   * <ul>
065   * <li> For version 1 (GNU Classpath default), that data (if present) are
066   * written "as is". </li>
067   * <li>For version 2, this data fragment is enclosed within a CDR custom
068   * valuetype with no codebase and repository Id "RMI:org.omg.custom.<class>"
069   * where <class> is the fully-qualified name of the class whose writeObject
070   * method is being invoked. If the object does not write any data via
071   * writeObject method, the null valuetype (0x0) must be written.</li>
072   * </ul>
073   * As the version number is part of the value type record, there is no need
074   * to the format control during the reading.
075   *
076   * @return the maximal supported version.
077   */
078  byte getMaximumStreamFormatVersion();
079
080  /**
081   * Write the value type to the output stream using the given format version.
082   * The older method {@link ValueHandler#writeValue} always uses the version 1.
083   *
084   * @param output the stream, where the value should be written, must implement
085   * {@link ValueOutputStream}.
086   * @param value the value that should be written.
087   * @param version the version of the format that must be used to write the
088   * value.
089   *
090   * @throws BAD_PARAM if the version number is less than 1 or greater than the
091   * maximal supported version.
092   */
093  void writeValue(OutputStream output, Serializable value, byte version);
094}