001    /* ValueHandlerMultiFormat.java --
002       Copyright (C) 2005 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 javax.rmi.CORBA;
040    
041    import org.omg.CORBA.portable.OutputStream;
042    
043    import 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     */
054    public 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    }