wireformatmessagebinary.java

jxta_src_2.41b jxta 2.41b 最新版源码 from www.jxta.org

/************************************************************************
 *
 * $Id: WireFormatMessageBinary.java,v 1.27 2006/06/21 19:39:18 bondolo Exp $
 *
 * Copyright (c) 2001-2006 Sun Microsystems, Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *       Sun Microsystems, Inc. for Project JXTA."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA"
 *    must not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact Project JXTA at http://www.jxta.org.
 *
 * 5. Products derived from this software may not be called "JXTA",
 *    nor may "JXTA" appear in their name, without prior written
 *    permission of Sun.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL SUN MICROSYSTEMS  OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of Project JXTA.  For more
 * information on Project JXTA, please see
 * <http://www.jxta.org/>.
 *
 * This license is based on the BSD license adopted by the Apache Foundation.
 *********************************************************************************/

package net.jxta.impl.endpoint;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.SequenceInputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import java.io.IOException;
import java.io.EOFException;

import org.apache.log4j.Logger;
import org.apache.log4j.Level;

import net.jxta.document.Document;
import net.jxta.document.MimeMediaType;
import net.jxta.endpoint.ByteArrayMessageElement;
import net.jxta.endpoint.Message;
import net.jxta.endpoint.MessageElement;
import net.jxta.endpoint.WireFormatMessage;
import net.jxta.endpoint.WireFormatMessageFactory;
import net.jxta.util.LimitInputStream;

/**
 *  A Wire Format Message which encodes the message into MIME Type
 *  "application/x-jxta-msg".
 *
 *  <p/>This implementation does nothing with encodings.
 *
 *  <p/>This implementation does not use any MIME parameters attached to the
 *  requesting mime type.
 *
 *  @see net.jxta.endpoint.WireFormatMessageFactory
 *  @see <a href="http://spec.jxta.org/nonav/v1.0/docbook/JXTAProtocols.html#msgs-fmts-jbm" target="_blank">JXTA Protocols Specification : Binary Message Format</a>
 **/
public class WireFormatMessageBinary implements WireFormatMessage {
    
    /*
     *  Log4J Logger
     */
    private final static transient Logger LOG = Logger.getLogger( WireFormatMessageBinary.class.getName() );
    
    // Flag bits
    protected static final byte HAS_TYPE      = 0x01;
    protected static final byte HAS_ENCODING  = 0x02;
    protected static final byte HAS_SIGNATURE = 0x04;
    
    protected static final int MESSAGE_VERSION = 0;
    
    /**
     * Our Mime Media Type(s)
     **/
    private static final MimeMediaType [] myTypes = {
        MimeMediaType.valueOf( "application/x-jxta-msg" )
    };
    
    /**
     * These are the content encodings we support.
     **/
    private static final MimeMediaType [] myContentEncodings = {
        
        // we support raw binary!
        null
    };
    
    /**
     * Our instantiator for the factory.
     **/
    public static final WireFormatMessageFactory.Instantiator INSTANTIATOR = new Instantiator();
    
    /**
     *  Our instantiator.
     **/
    static class Instantiator implements WireFormatMessageFactory.Instantiator {
        
        /**
         * Creates new WireFormatMessageBinary Instantiator
         */
        public Instantiator() {
        }
        
        /**
         * {@inheritDoc}
         **/
        public MimeMediaType[] getSupportedMimeTypes() {
            return myTypes;
        }
        
        /**
         * {@inheritDoc}
         **/
        public MimeMediaType[] getSupportedContentEncodings() {
            return myContentEncodings;
        }
        
        /**
         * {@inheritDoc}
         **/
        public Message fromWire( InputStream is, MimeMediaType type, MimeMediaType contentEncoding ) throws IOException {
            // FIXME 20020504 [e-mail]  Ignores type and contentEncoding completely.
            Message msg = new Message();
            
            if ( LOG.isEnabledFor(Level.DEBUG) ) {
                LOG.debug( "Reading " + msg + " from " + is );
            }
            
            DataInputStream dis = new DataInputStream( is );
            
            HashMap idToNamespace = readHeader( dis );
            
            int elementCnt = dis.readShort();
            
            if ( LOG.isEnabledFor(Level.DEBUG) ) {
                LOG.debug( "Message element count " + elementCnt + " from " + is );
            }
            
            int eachElement = 0;
            do {
                if ( LOG.isEnabledFor(Level.DEBUG) ) {
                    LOG.debug( "Read element " + eachElement + " of " + elementCnt + " from " + is + " for " + msg );
                }
                
                Object [] anElement = null;
                
                try {
                    anElement = readMessageElement( dis, is );
                } catch ( IOException failed ) {
                    if ( LOG.isEnabledFor(Level.ERROR) ) {
                        LOG.error( "Failure reading element " + eachElement + " of " + elementCnt + " from " + is + " for " + msg, failed );
                    }
                    
                    throw failed;
                }
                
                if( null == anElement ) {
                    break;
                }
                
                String namespace = (String) idToNamespace.get(anElement[0]);
                
                if( null == namespace ) {
                    if ( LOG.isEnabledFor(Level.ERROR) ) {
                        LOG.error( "Element identified a namespace which was not defined for this message." );
                    }
                    
                    throw new IOException( "Element identified a namespace which was not defined for this message." );
                }
                
                msg.addMessageElement( namespace, (MessageElement) anElement[1] );
                eachElement++;
                
                if ( LOG.isEnabledFor(Level.DEBUG) ) {
                    LOG.debug( "Add element (name='" +
                    ((MessageElement) anElement[1]).getElementName() + "') #"
                    + eachElement + " of #" + elementCnt + " elements from "
                    + dis.toString() );
                }
            } while ( true && ((0 == elementCnt) || (eachElement < elementCnt)) );
            
            if( (elementCnt != 0) && (eachElement != elementCnt) ) {
                throw new IOException( "Found wrong number of elements in message." );
            }
            
            return msg;
        }
        
        /**
         * {@inheritDoc}
         **/
        public WireFormatMessage toWire(Message msg, MimeMediaType type, MimeMediaType[] preferedContentEncoding) {
            try {
                return new WireFormatMessageBinary( msg, type, preferedContentEncoding );
            } catch ( IOException caught ) {
                throw new IllegalStateException( "Could not build wire format for message due to " + caught.getMessage() );
            }
        }
        
        /**
         *  Read in a message header from the provided data stream.
         *
         *  @param dis  the data stream to read from
         *  @return hashmap containing the namespace id to namespace values
         *  @throws IOException if EOF or other IOException is encountered
         *  during the reading of the header.
         **/
        private static HashMap readHeader( DataInputStream dis ) throws IOException {
            // Read message signature
            char [] msgsig = new char[4];
            
            try {
                msgsig[0] = (char) dis.readByte();
            } catch( EOFException failed ) {
                if ( LOG.isEnabledFor(Level.DEBUG) ) {
                    LOG.debug( "EOF reading message at first byte of header.", failed );
                }
                
                throw failed;
            }
            msgsig[1] = (char) dis.readByte();
            msgsig[2] = (char) dis.readByte();
            msgsig[3] = (char) dis.readByte();
            
            if ( msgsig[0] != 'j' || msgsig[1] != 'x' || msgsig[2] != 'm' || msgsig[3] != 'g') {
                IOException failure = new IOException( "Not a message (incorrect signature '" +
                msgsig[0] + msgsig[1] + msgsig[2] + msgsig[3]
                + "') "  );
                
                if ( LOG.isEnabledFor(Level.ERROR) ) {
                    LOG.error( failure );
                }
                
                throw failure;
            }
            
            // Message version
            if (dis.readByte() != MESSAGE_VERSION ) {
                IOException failure = new IOException( "Message not version " + MESSAGE_VERSION );
                
                if ( LOG.isEnabledFor(Level.ERROR) ) {
                    LOG.error( failure, failure );
                }
                
                throw failure;
            }
            
            int namespaceCnt = dis.readShort();
            
            if( namespaceCnt > 253 ) {
                IOException failure = new IOException( "Message contains too many namespaces (>253)" );
                
                if ( LOG.isEnabledFor(Level.ERROR) ) {
                    LOG.error( failure, failure );
                }
                
                throw failure;
            }
            
            HashMap id2namespace = new HashMap( 2 + namespaceCnt );
            id2namespace.put(new Integer(0), "");