multipartiterator.java

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/*
 * $Header: /sfroot/cvs/esimple/src/core/org/apache/struts/upload/MultipartIterator.java,v 1.1.1.1 2004/09/08 06:38:41 lava Exp $
 * $Revision: 1.1.1.1 $
 * $Date: 2004/09/08 06:38:41 $
 *
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999-2002 The Apache Software Foundation.  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 acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Struts", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact [e-mail].
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 * 5. Products derived from this software may not be called "Apache"
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 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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 * 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 the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.struts.upload;

import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

import javax.servlet.http.HttpServletRequest;

/**
 * The MultipartIterator class is responsible for reading the
 * input data of a multipart request and splitting it up into
 * input elements, wrapped inside of a
 * {@link org.apache.struts.upload.MultipartElement MultipartElement}
 * for easy definition.  To use this class, create a new instance
 * of MultipartIterator passing it a HttpServletRequest in the
 * constructor.  Then use the {@link #getNextElement() getNextElement}
 * method until it returns null, then you're finished.  Example: <br>
 * <pre>
 *      MultipartIterator iterator = new MultipartIterator(request);
 *      MultipartElement element;
 *
 *      while ((element = iterator.getNextElement()) != null) {
 *           //do something with element
 *      }
 * </pre>
 *
 * @see org.apache.struts.upload.MultipartElement
 * @author Mike Schachter
 */
public class MultipartIterator
{

    /**
     * The default encoding of a text element if none is specified.
     */
    private static final String DEFAULT_ENCODING = "iso-8859-1";

    /**
     * The size in bytes to copy of text data at a time.
     */
    private static final int TEXT_BUFFER_SIZE = 1000;

    /**
     * The name of the Content-Type header.
     */
    public static String HEADER_CONTENT_TYPE = "Content-Type";

    /**
     * The name of the Content-Disposition header.
     */
    public static final String HEADER_CONTENT_DISPOSITION = "Content-Disposition";

    /**
     * The exception message for when the boundary of a multipart request can't be determined.
     */
    public static final String MESSAGE_CANNOT_RETRIEVE_BOUNDARY =
                                                    "MultipartIterator: cannot retrieve boundary for multipart request";

    private static final String PARAMETER_BOUNDARY = "boundary=";

    private static final String FILE_PREFIX = "strts";

    /**
     * The request instance for this class
     */
    protected HttpServletRequest request;

    /**
     * The InputStream to use to read the multipart data.
     */
    protected MultipartBoundaryInputStream inputStream;

    /**
     * The boundary for this multipart request
     */
    protected String boundary;

    /**
     * The maximum file size in bytes allowed. Ignored if -1
     */
    protected long maxSize = -1;

    /**
     * The content length of this request
     */
    protected int contentLength;

    /**
     * The size in bytes written to the filesystem at a time [20K]
     */
    protected int diskBufferSize = 2 * 10240;

    /**
     * The amount of data read from a request at a time.
     * This also represents the maximum size in bytes of
     * a line read from the request [4KB]
     */
    protected int bufferSize = 4096;

    /**
     * The temporary directory to store files
     */
    protected String tempDir;

    /**
     * The content-type.
     */
    protected String contentType;

    /**
     * Whether the maximum length has been exceeded.
     */
    protected boolean maxLengthExceeded;

    /**
     * Constructs a MultipartIterator with a default buffer size and no file size
     * limit
     *
     * @param request The multipart request to iterate
     */
    public MultipartIterator(HttpServletRequest request) throws IOException
    {
        this(request, -1);
    }

    /**
     * Constructs a MultipartIterator with the specified buffer size and
     * no file size limit
     *
     * @param request The multipart request to iterate
     * @param bufferSize The size in bytes that should be read from the input
     *                   stream at a times
     */
    public MultipartIterator(HttpServletRequest request, int bufferSize) throws IOException
    {
        this (request, bufferSize, -1);
    }

    /**
     * Constructs a MultipartIterator with the specified buffer size and
     * the specified file size limit in bytes
     *
     * @param request The multipart request to iterate
     * @param bufferSize The size in bytes that should be read from the input
     *                   stream at a times
     * @param maxSize The maximum size in bytes allowed for a multipart element's data
     */
    public MultipartIterator(HttpServletRequest request, int bufferSize, long maxSize) throws IOException
    {
        this(request, bufferSize, maxSize, null);
    }

    public MultipartIterator(HttpServletRequest request, int bufferSize, long maxSize, String tempDir) throws IOException
    {
        this.request = request;
        this.maxSize = maxSize;
        if (bufferSize > -1)
        {
            this.bufferSize = bufferSize;
        }
        if (tempDir != null)
        {
            this.tempDir = tempDir;
        }