Tomcat example source code file (IdentityInputFilter.java)

This example Tomcat source code file (IdentityInputFilter.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, bytechunk, encoding, encoding, encoding_name, identityinputfilter, inputbuffer, inputfilter, io, ioexception, ioexception, request, request, string

The Tomcat IdentityInputFilter.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.coyote.http11.filters;

import java.io.IOException;

import org.apache.tomcat.util.buf.ByteChunk;

import org.apache.coyote.InputBuffer;
import org.apache.coyote.Request;
import org.apache.coyote.http11.InputFilter;

/**
 * Identity input filter.
 * 
 * @author Remy Maucherat
 */
public class IdentityInputFilter implements InputFilter {


    // -------------------------------------------------------------- Constants


    protected static final String ENCODING_NAME = "identity";
    protected static final ByteChunk ENCODING = new ByteChunk();


    // ----------------------------------------------------- Static Initializer


    static {
        ENCODING.setBytes(ENCODING_NAME.getBytes(), 0, ENCODING_NAME.length());
    }


    // ----------------------------------------------------- Instance Variables


    /**
     * Content length.
     */
    protected long contentLength = -1;


    /**
     * Remaining bytes.
     */
    protected long remaining = 0;


    /**
     * Next buffer in the pipeline.
     */
    protected InputBuffer buffer;


    /**
     * Chunk used to read leftover bytes.
     */
    protected ByteChunk endChunk = new ByteChunk();


    // ------------------------------------------------------------- Properties


    /**
     * Get content length.
     */
    public long getContentLength() {
        return contentLength;
    }


    /**
     * Get remaining bytes.
     */
    public long getRemaining() {
        return remaining;
    }


    // ---------------------------------------------------- InputBuffer Methods


    /**
     * Read bytes.
     * 
     * @return If the filter does request length control, this value is
     * significant; it should be the number of bytes consumed from the buffer,
     * up until the end of the current request body, or the buffer length, 
     * whichever is greater. If the filter does not do request body length
     * control, the returned value should be -1.
     */
    public int doRead(ByteChunk chunk, Request req)
        throws IOException {

        int result = -1;

        if (contentLength >= 0) {
            if (remaining > 0) {
                int nRead = buffer.doRead(chunk, req);
                if (nRead > remaining) {
                    // The chunk is longer than the number of bytes remaining
                    // in the body; changing the chunk length to the number
                    // of bytes remaining
                    chunk.setBytes(chunk.getBytes(), chunk.getStart(), 
                                   (int) remaining);
                    result = (int) remaining;
                } else {
                    result = nRead;
                }
                remaining = remaining - nRead;
            } else {
                // No more bytes left to be read : return -1 and clear the 
                // buffer
                chunk.recycle();
                result = -1;
            }
        }

        return result;

    }


    // ---------------------------------------------------- InputFilter Methods


    /**
     * Read the content length from the request.
     */
    public void setRequest(Request request) {
        contentLength = request.getContentLengthLong();
        remaining = contentLength;
    }


    /**
     * End the current request.
     */
    public long end()
        throws IOException {

        // Consume extra bytes.
        while (remaining > 0) {
            int nread = buffer.doRead(endChunk, null);
            if (nread > 0 ) {
                remaining = remaining - nread;
            } else { // errors are handled higher up.
                remaining = 0;
            }
        }

        // If too many bytes were read, return the amount.
        return -remaining;

    }


    /**
     * Amount of bytes still available in a buffer.
     */
    public int available() {
        return 0;
    }
    

    /**
     * Set the next buffer in the filter pipeline.
     */
    public void setBuffer(InputBuffer buffer) {
        this.buffer = buffer;
    }


    /**
     * Make the filter ready to process the next request.
     */
    public void recycle() {
        contentLength = -1;
        remaining = 0;
        endChunk.recycle();
    }


    /**
     * Return the name of the associated encoding; Here, the value is 
     * "identity".
     */
    public ByteChunk getEncodingName() {
        return ENCODING;
    }


}