welcomemessage.java

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

        do {
            int c = in.read();
            
            switch( c ) {
                case -1 :
                    throw new EOFException( "Stream terminated before end of welcome message" );
                    
                case '\r' :
                    if( sawCR ) {
                        welcomeBytes[readAt++] = (byte) 0x0D;
                    }
                    
                    sawCR = true;
                    break;
                    
                case '\n' :
                    if( sawCR ) {
                        sawCRLF = true;
                    } else {
                        welcomeBytes[readAt++] = (byte) 0x0A;
                    }
                    break;
                    
                default :
                    welcomeBytes[readAt++] = (byte) c;
                    sawCR = false;
            }
            
            if( readAt == welcomeBytes.length ) {
                throw new IOException( "Invalid welcome message, too long" );
            }
            
        } while( !sawCRLF );
        
        byte [] truncatedBytes = new byte [readAt];
        
        System.arraycopy( welcomeBytes, 0, truncatedBytes, 0, readAt );
        
        welcomeBytes = truncatedBytes;
        
        welcomeString = new String( welcomeBytes, "UTF-8" );
        
        // we have the message, parse it.
        List<String> thePieces = Arrays.asList( welcomeString.split( "\\s" ) );
        
        if( 0 == thePieces.size() ) {
            throw new IOException( "Invalid welcome message, did not contain any tokens." );
        }
        
        if( thePieces.size() < 5 ) {
            throw new IOException( "Invalid welcome message, did not contain enough tokens." );
        }
        
        if( !GREETING.equals(thePieces.get(0)) ) {
            throw new IOException( "Invalid welcome message, did not start with greeting" );
        }
        
        try {
            destinationAddress = new EndpointAddress( thePieces.get(1) );
        } catch( IllegalArgumentException badAddress ) {
            IOException failed = new IOException( "Invalid welcome message, bad destination address" );
            
            failed.initCause( badAddress );
            
            throw failed;
        }
        
        try {
            publicAddress = new EndpointAddress( thePieces.get(2) );
        } catch( IllegalArgumentException badAddress ) {
            IOException failed = new IOException( "Invalid welcome message, bad publicAddress address" );
            
            failed.initCause( badAddress );
            
            throw failed;
        }
        
        try {
            URI peerURI =  new URI( thePieces.get(3) );
            
            peerID = IDFactory.fromURI( peerURI );
        } catch( URISyntaxException badURI ) {
            IOException failed = new IOException( "Invalid welcome message, bad peer id" );
            
            failed.initCause( badURI );
            
            throw failed;
        }
        
        versionString  = thePieces.get( thePieces.size() - 1 );
        
        if( WELCOME_VERSION_1_1.equals(versionString) ) {
            if( 6 != thePieces.size() )  {
                throw new IOException( "Invalid welcome message, incorrect number of tokens." );
            }
            
            String noPropagateStr = thePieces.get(4);
            
            if( noPropagateStr.equals( "1" ) ) {
                noPropagate = true;
            } else if( noPropagateStr.equals( "0" ) ) {
                noPropagate = false;
            } else {
                throw new IOException( "Invalid welcome message, illegal value for propagate flag" );
            }
            
            // preferred message version is not set in 
            preferredMessageVersion = 0;
        } else if( WELCOME_VERSION_3_0.equals(versionString) ) {
            if( 7 != thePieces.size() )  {
                throw new IOException( "Invalid welcome message, incorrect number of tokens." );
            }
            
            String noPropagateStr = thePieces.get(4);
            
            if( noPropagateStr.equals( "1" ) ) {
                noPropagate = true;
            } else if( noPropagateStr.equals( "0" ) ) {
                noPropagate = false;
            } else {
                throw new IOException( "Invalid welcome message, illegal value for propagate flag" );
            }
            
            String preferredVersionStr = thePieces.get(5);

            try {
                preferredMessageVersion = Integer.valueOf(preferredVersionStr); 
            } catch( IllegalArgumentException failed ) {
                IOException failure = new IOException( "Invalid welcome message, illegal value for preferred message version" );
                failure.initCause(failed);
                
                throw failure;
            }
        } else {
            // Unrecognized Welcome message version. Use default values.
            noPropagate = false;
            preferredMessageVersion = 0;
        }
    }
    
    /**
     *  Write the welcome message to the provided stream.
     *
     *  @param theStream The OutputStream to which to write the welcome message.
     *  @throws IOException If there is a problem writing the welcome message.
     */
    public void sendToStream( OutputStream theStream ) throws IOException {
        theStream.write( welcomeBytes );
        theStream.write( '\r' );
        theStream.write( '\n' );
    }
    
    /**
     *  Return the peerid associated with the Welcome Message.
     *
     *  @return The peer ID from the Welcome Message.
     */
    public ID getPeerID() {
        return peerID;
    }
    
    /**
     *  Return the source address associated with the Welcome Message.
     *
     *  @return The source address from the Welcome Message.
     */
    public EndpointAddress getPublicAddress() {
        return publicAddress;
    }
    
    /**
     *  Return the destination address associated with the Welcome Message.
     *
     *  @return The destination address from the Welcome Message.
     */
    public EndpointAddress getDestinationAddress() {
        return destinationAddress;
    }
    
    /**
     *  Return the propagation preference from the Welcome Message.
     *
     *  @return <tt>true</tt> if <strong>no</strong> propagation is desired
     *  otherwise <tt>false</tt>
     */
    public boolean dontPropagate() {
        return noPropagate;
    }
    
    /**
     *  Return the preferred message version from the Welcome Message.
     *
     *  @return The preferred Message Version.
     */
    public int getPreferredMessageVersion() {
        return preferredMessageVersion;
    }
    
    /**
     *  Return the version associated with the Welcome Message.
     *
     *  @return The version from the Welcome Message.
     */
    public String getWelcomeVersion() {
        return versionString;
    }
    
    /**
     *  Return a String containing the Welcome Message.
     *
     *  @return a String containing the Welcome Message.
     */
    public String getWelcomeString() {
        return welcomeString;
    }
}