Tomcat example source code file (JkInputStream.java)

This example Tomcat source code file (JkInputStream.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Tomcat tags/keywords

bytechunk, inputbuffer, io, ioexception, ioexception, jkinputstream, jkinputstream, messagebytes, messagebytes, mimeheaders, msg, msgajp, msgcontext, string, string

The Tomcat JkInputStream.java source code

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package org.apache.jk.common;

import java.io.IOException;

import org.apache.coyote.OutputBuffer;
import org.apache.coyote.InputBuffer;
import org.apache.coyote.Request;
import org.apache.coyote.Response;

import org.apache.jk.core.Msg;
import org.apache.jk.core.MsgContext;

import org.apache.tomcat.util.buf.ByteChunk;
import org.apache.tomcat.util.buf.MessageBytes;
import org.apache.tomcat.util.buf.C2BConverter;
import org.apache.tomcat.util.http.HttpMessages;
import org.apache.tomcat.util.http.MimeHeaders;

/** Generic input stream impl on top of ajp
 */
public class JkInputStream implements InputBuffer, OutputBuffer {
    private static org.apache.juli.logging.Log log=
        org.apache.juli.logging.LogFactory.getLog( JkInputStream.class );

    private Msg bodyMsg;
    private Msg outputMsg;
    private MsgContext mc;

    
    // Holds incoming chunks of request body data
    private MessageBytes bodyBuff = MessageBytes.newInstance();
    private MessageBytes tempMB = MessageBytes.newInstance();
    private boolean end_of_stream=false; 
    private boolean isEmpty = true;
    private boolean isFirst = true;
    private boolean isReplay = false;
    private boolean isReadRequired = false;

    static {
        // Make certain HttpMessages is loaded for SecurityManager
        try {
            Class.forName("org.apache.tomcat.util.http.HttpMessages");
        } catch(Exception ex) {
            // ignore
        }
    }

    public JkInputStream(MsgContext context, int bsize) {
        mc = context;
        bodyMsg = new MsgAjp(bsize);
        outputMsg = new MsgAjp(bsize);
    }
    /**
     * @deprecated
     */
    public JkInputStream(MsgContext context) {
        this(context, 8*1024);
    }

    // -------------------- Jk specific methods --------------------


    /**
     * Set the flag saying that the server is sending a body
     */
    public void setIsReadRequired(boolean irr) {
        isReadRequired = irr;
    }

    /**
     * Return the flag saying that the server is sending a body
     */
    public boolean isReadRequired() {
        return isReadRequired;
    }

    
    /** Must be called before or after each request
     */
    public void recycle() {
        if(isReadRequired && isFirst) {
            // The Servlet never read the request body, so we need to junk it
            try {
              receive();
            } catch(IOException iex) {
              log.debug("Error consuming request body",iex);
            }
        }

        end_of_stream = false;
        isEmpty = true;
        isFirst = true;
        isReplay = false;
        isReadRequired = false;
        bodyBuff.recycle();
        tempMB.recycle();
    }


    public void endMessage() throws IOException {
        outputMsg.reset();
        outputMsg.appendByte(AjpConstants.JK_AJP13_END_RESPONSE);
        outputMsg.appendByte(1);
        mc.getSource().send(outputMsg, mc);
        mc.getSource().flush(outputMsg, mc);
    }


    // -------------------- OutputBuffer implementation --------------------

        
    public int doWrite(ByteChunk chunk, Response res) 
        throws IOException    {
        if (!res.isCommitted()) {
            // Send the connector a request for commit. The connector should
            // then validate the headers, send them (using sendHeader) and 
            // set the filters accordingly.
            res.sendHeaders();
        }

        int len=chunk.getLength();
        byte buf[]=outputMsg.getBuffer();
        // 4 - hardcoded, byte[] marshalling overhead 
        int chunkSize=buf.length - outputMsg.getHeaderLength() - 4;
        int off=0;
        while( len > 0 ) {
            int thisTime=len;
            if( thisTime > chunkSize ) {
                thisTime=chunkSize;
            }
            len-=thisTime;
            
            outputMsg.reset();
            outputMsg.appendByte( AjpConstants.JK_AJP13_SEND_BODY_CHUNK);
            if( log.isTraceEnabled() ) 
                log.trace("doWrite " + off + " " + thisTime + " " + len );
            outputMsg.appendBytes( chunk.getBytes(), chunk.getOffset() + off, thisTime );
            off+=thisTime;
            mc.getSource().send( outputMsg, mc );
        }
        return 0;
    }

    public int doRead(ByteChunk responseChunk, Request req) 
        throws IOException {

        if( log.isDebugEnabled())
            log.debug( "doRead "  + end_of_stream+
                       " " + responseChunk.getOffset()+ " " + responseChunk.getLength());
        if( end_of_stream ) {
            return -1;
        }

        if( isFirst && isReadRequired ) {
            // Handle special first-body-chunk, but only if httpd expects it.
            if( !receive() ) {
                return 0;
            }
        } else if(isEmpty) {
            if ( !refillReadBuffer() ){
                return -1;
            }
        }
        ByteChunk bc = bodyBuff.getByteChunk();
        responseChunk.setBytes( bc.getBuffer(), bc.getStart(), bc.getLength() );
        isEmpty = true;
        return responseChunk.getLength();
    }
    
    /** Receive a chunk of data. Called to implement the
     *  'special' packet in ajp13 and to receive the data
     *  after we send a GET_BODY packet
     */
    public boolean receive() throws IOException {
        isFirst = false;
        bodyMsg.reset();
        int err = mc.getSource().receive(bodyMsg, mc);
        if( log.isDebugEnabled() )
            log.info( "Receiving: getting request body chunk " + err + " " + bodyMsg.getLen() );
        
        if(err < 0) {
            throw new IOException();
        }

        // No data received.
        if( bodyMsg.getLen() == 0 ) { // just the header
            // Don't mark 'end of stream' for the first chunk.
            // end_of_stream = true;
            return false;
        }
        int blen = bodyMsg.peekInt();

        if( blen == 0 ) {
            return false;
        }

        if( log.isTraceEnabled() ) {
            bodyMsg.dump("Body buffer");
        }
        
        bodyMsg.getBytes(bodyBuff);
        if( log.isTraceEnabled() )
            log.trace( "Data:\n" + bodyBuff);
        isEmpty = false;
        return true;
    }
    
    /**
     * Get more request body data from the web server and store it in the 
     * internal buffer.
     *
     * @return true if there is more data, false if not.    
     */
    private boolean refillReadBuffer() throws IOException 
    {
        // If the server returns an empty packet, assume that that end of
        // the stream has been reached (yuck -- fix protocol??).
        if(isReplay) {
            end_of_stream = true; // we've read everything there is
        }
        if (end_of_stream) {
            if( log.isDebugEnabled() ) 
                log.debug("refillReadBuffer: end of stream " );
            return false;
        }

        // Why not use outBuf??
        bodyMsg.reset();
        bodyMsg.appendByte(AjpConstants.JK_AJP13_GET_BODY_CHUNK);
        bodyMsg.appendInt(AjpConstants.MAX_READ_SIZE);
        
        if( log.isDebugEnabled() )
            log.debug("refillReadBuffer " + Thread.currentThread());

        mc.getSource().send(bodyMsg, mc);
        mc.getSource().flush(bodyMsg, mc); // Server needs to get it

        // In JNI mode, response will be in bodyMsg. In TCP mode, response need to be
        // read

        boolean moreData=receive();
        if( !moreData ) {
            end_of_stream=true;
        }
        return moreData;
    }

    public void appendHead(Response res) throws IOException {
        if( log.isDebugEnabled() )
            log.debug("COMMIT sending headers " + res + " " + res.getMimeHeaders() );
        
        C2BConverter c2b=mc.getConverter();
        
        outputMsg.reset();
        outputMsg.appendByte(AjpConstants.JK_AJP13_SEND_HEADERS);
        outputMsg.appendInt( res.getStatus() );
        
        String message=res.getMessage();
        if( message==null ){
            message= HttpMessages.getMessage(res.getStatus());
        } else {
            message = message.replace('\n', ' ').replace('\r', ' ');
        }
        tempMB.setString( message );
        c2b.convert( tempMB );
        outputMsg.appendBytes(tempMB);

        // XXX add headers
        
        MimeHeaders headers=res.getMimeHeaders();
        String contentType = res.getContentType();
        if( contentType != null ) {
            headers.setValue("Content-Type").setString(contentType);
        }
        String contentLanguage = res.getContentLanguage();
        if( contentLanguage != null ) {
            headers.setValue("Content-Language").setString(contentLanguage);
        }
        long contentLength = res.getContentLengthLong();
        if( contentLength >= 0 ) {
            headers.setValue("Content-Length").setLong(contentLength);
        }
        int numHeaders = headers.size();
        outputMsg.appendInt(numHeaders);
        for( int i=0; i<numHeaders; i++ ) {
            MessageBytes hN=headers.getName(i);
            // no header to sc conversion - there's little benefit
            // on this direction
            c2b.convert ( hN );
            outputMsg.appendBytes( hN );
                        
            MessageBytes hV=headers.getValue(i);
            c2b.convert( hV );
            outputMsg.appendBytes( hV );
        }
        mc.getSource().send( outputMsg, mc );
    }

    /**
     * Set the replay buffer for Form auth
     */
    public void setReplay(ByteChunk replay) {
        isFirst = false;
        isEmpty = false;
        isReplay = true;
        bodyBuff.setBytes(replay.getBytes(), replay.getStart(), replay.getLength());
    }


}