/*

 * 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.tomcat.util.http.fileupload;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import javax.servlet.http.HttpServletRequest;

/**

 * <p>High level API for processing file uploads.</p>

 *

 * <p>This class handles multiple files per single HTML widget, sent using

 * <code>multipart/mixed</code> encoding type, as specified by

 * <a href="http://www.ietf.org/rfc/rfc1867.txt">RFC 1867</a>.  Use {@link

 * #parseRequest(HttpServletRequest)} to acquire a list of {@link

 * org.apache.tomcat.util.http.fileupload.FileItem}s associated with a given HTML

 * widget.</p>

 *

 * <p>How the data for individual parts is stored is determined by the factory

 * used to create them; a given part may be in memory, on disk, or somewhere

 * else.</p>

 *

 * @author <a href="mailto:Rafal.Krzewski@e-point.pl">Rafal Krzewski</a>

 * @author <a href="mailto:dlr@collab.net">Daniel Rall</a>

 * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>

 * @author <a href="mailto:jmcnally@collab.net">John McNally</a>

 * @author <a href="mailto:martinc@apache.org">Martin Cooper</a>

 * @author Sean C. Sullivan

 *

 */

public abstract class FileUploadBase

{

    // ---------------------------------------------------------- Class methods

    /**

     * Utility method that determines whether the request contains multipart

     * content.

     *

     * @param req The servlet request to be evaluated. Must be non-null.

     *

     * @return <code>true</code> if the request is multipart;

     *         <code>false</code> otherwise.

     */

    public static final boolean isMultipartContent(HttpServletRequest req)

    {

        String contentType = req.getHeader(CONTENT_TYPE);

        if (contentType == null)

        {

            return false;

        }

        if (contentType.startsWith(MULTIPART))

        {

            return true;

        }

        return false;

    }

    // ----------------------------------------------------- Manifest constants

    /**

     * HTTP content type header name.

     */

    public static final String CONTENT_TYPE = "Content-type";

    /**

     * HTTP content disposition header name.

     */

    public static final String CONTENT_DISPOSITION = "Content-disposition";

    /**

     * Content-disposition value for form data.

     */

    public static final String FORM_DATA = "form-data";

    /**

     * Content-disposition value for file attachment.

     */

    public static final String ATTACHMENT = "attachment";

    /**

     * Part of HTTP content type header.

     */

    public static final String MULTIPART = "multipart/";

    /**

     * HTTP content type header for multipart forms.

     */

    public static final String MULTIPART_FORM_DATA = "multipart/form-data";

    /**

     * HTTP content type header for multiple uploads.

     */

    public static final String MULTIPART_MIXED = "multipart/mixed";

    /**

     * The maximum length of a single header line that will be parsed

     * (1024 bytes).

     */

    public static final int MAX_HEADER_SIZE = 1024;

    // ----------------------------------------------------------- Data members

    /**

     * The maximum size permitted for an uploaded file. A value of -1 indicates

     * no maximum.

     */

    private long sizeMax = -1;

    /**

     * The content encoding to use when reading part headers.

     */

    private String headerEncoding;

    // ----------------------------------------------------- Property accessors

    /**

     * Returns the factory class used when creating file items.

     *

     * @return The factory class for new file items.

     */

    public abstract FileItemFactory getFileItemFactory();

    /**

     * Sets the factory class to use when creating file items.

     *

     * @param factory The factory class for new file items.

     */

    public abstract void setFileItemFactory(FileItemFactory factory);

    /**

     * Returns the maximum allowed upload size.

     *

     * @return The maximum allowed size, in bytes.

     *

     * @see #setSizeMax(long)

     *

     */

    public long getSizeMax()

    {

        return sizeMax;

    }

    /**

     * Sets the maximum allowed upload size. If negative, there is no maximum.

     *

     * @param sizeMax The maximum allowed size, in bytes, or -1 for no maximum.

     *

     * @see #getSizeMax()

     *

     */

    public void setSizeMax(long sizeMax)

    {

        this.sizeMax = sizeMax;

    }

    /**

     * Retrieves the character encoding used when reading the headers of an

     * individual part. When not specified, or <code>null</code>, the platform

     * default encoding is used.

     *

     * @return The encoding used to read part headers.

     */

    public String getHeaderEncoding()

    {

        return headerEncoding;

    }

    /**

     * Specifies the character encoding to be used when reading the headers of

     * individual parts. When not specified, or <code>null</code>, the platform

     * default encoding is used.

     *

     * @param encoding The encoding used to read part headers.

     */

    public void setHeaderEncoding(String encoding)

    {

        headerEncoding = encoding;

    }

    // --------------------------------------------------------- Public methods

    /**

     * Processes an <a href="http://www.ietf.org/rfc/rfc1867.txt">RFC 1867</a>

     * compliant <code>multipart/form-data</code> stream. If files are stored

     * on disk, the path is given by <code>getRepository()</code>.

     *

     * @param req The servlet request to be parsed.

     *

     * @return A list of <code>FileItem</code> instances parsed from the

     *         request, in the order that they were transmitted.

     *

     * @exception FileUploadException if there are problems reading/parsing

     *                                the request or storing files.

     */

    public List /* FileItem */ parseRequest(HttpServletRequest req)

        throws FileUploadException

    {

        if (null == req)

        {

            throw new NullPointerException("req parameter");

        }

        ArrayList items = new ArrayList();

        String contentType = req.getHeader(CONTENT_TYPE);

        if ((null == contentType) || (!contentType.startsWith(MULTIPART)))

        {

            throw new InvalidContentTypeException(

                "the request doesn't contain a "

                + MULTIPART_FORM_DATA

                + " or "

                + MULTIPART_MIXED

                + " stream, content type header is "

                + contentType);

        }

        int requestSize = req.getContentLength();

        if (requestSize == -1)

        {

            throw new UnknownSizeException(

                "the request was rejected because it's size is unknown");

        }

        if (sizeMax >= 0 && requestSize > sizeMax)

        {

            throw new SizeLimitExceededException(

                "the request was rejected because "

                + "it's size exceeds allowed range");

        }

        try

        {

            int boundaryIndex = contentType.indexOf("boundary=");

            if (boundaryIndex < 0)

            {

                throw new FileUploadException(

                        "the request was rejected because "

                        + "no multipart boundary was found");

            }

            byte[] boundary = contentType.substring(

                    boundaryIndex + 9).getBytes();

            InputStream input = req.getInputStream();

            MultipartStream multi = new MultipartStream(input, boundary);

            multi.setHeaderEncoding(headerEncoding);

            boolean nextPart = multi.skipPreamble();

            while (nextPart)

            {

                Map headers = parseHeaders(multi.readHeaders());

                String fieldName = getFieldName(headers);

                if (fieldName != null)

                {

                    String subContentType = getHeader(headers, CONTENT_TYPE);

                    if (subContentType != null && subContentType

                                                .startsWith(MULTIPART_MIXED))

                    {

                        // Multiple files.

                        byte[] subBoundary =

                            subContentType.substring(

                                subContentType

                                .indexOf("boundary=") + 9).getBytes();

                        multi.setBoundary(subBoundary);

                        boolean nextSubPart = multi.skipPreamble();

                        while (nextSubPart)

                        {

                            headers = parseHeaders(multi.readHeaders());

                            if (getFileName(headers) != null)

                            {

                                FileItem item =

                                        createItem(headers, false);

                                OutputStream os = item.getOutputStream();

                                try

                                {

                                    multi.readBodyData(os);

                                }

                                finally

                                {

                                    os.close();

                                }

                                items.add(item);

                            }

                            else

                            {

                                // Ignore anything but files inside

                                // multipart/mixed.

                                multi.discardBodyData();

                            }

                            nextSubPart = multi.readBoundary();

                        }

                        multi.setBoundary(boundary);

                    }

                    else

                    {

                        if (getFileName(headers) != null)

                        {

                            // A single file.

                            FileItem item = createItem(headers, false);

                            OutputStream os = item.getOutputStream();

                            try

                            {

                                multi.readBodyData(os);

                            }

                            finally

                            {

                                os.close();

                            }

                            items.add(item);

                        }

                        else

                        {

                            // A form field.

                            FileItem item = createItem(headers, true);

                            OutputStream os = item.getOutputStream();

                            try

                            {

                                multi.readBodyData(os);

                            }

                            finally

                            {

                                os.close();

                            }

                            items.add(item);

                        }

                    }

                }

                else

                {

                    // Skip this part.

                    multi.discardBodyData();

                }

                nextPart = multi.readBoundary();

            }

        }

        catch (IOException e)

        {

            throw new FileUploadException(

                "Processing of " + MULTIPART_FORM_DATA

                    + " request failed. " + e.getMessage());

        }

        return items;

    }

    // ------------------------------------------------------ Protected methods

    /**

     * Retrieves the file name from the <code>Content-disposition</code>

     * header.

     *

     * @param headers A <code>Map</code> containing the HTTP request headers.

     *

     * @return The file name for the current <code>encapsulation</code>.

     */

    protected String getFileName(Map /* String, String */ headers)

    {

        String fileName = null;

        String cd = getHeader(headers, CONTENT_DISPOSITION);

        if (cd.startsWith(FORM_DATA) || cd.startsWith(ATTACHMENT))

        {

            int start = cd.indexOf("filename=\"");

            int end = cd.indexOf('"', start + 10);

            if (start != -1 && end != -1)

            {

                fileName = cd.substring(start + 10, end).trim();

            }

        }

        return fileName;

    }

    /**

     * Retrieves the field name from the <code>Content-disposition</code>

     * header.

     *

     * @param headers A <code>Map</code> containing the HTTP request headers.

     *

     * @return The field name for the current <code>encapsulation</code>.

     */

    protected String getFieldName(Map /* String, String */ headers)

    {

        String fieldName = null;

        String cd = getHeader(headers, CONTENT_DISPOSITION);

        if (cd != null && cd.startsWith(FORM_DATA))

        {

            int start = cd.indexOf("name=\"");

            int end = cd.indexOf('"', start + 6);

            if (start != -1 && end != -1)

            {

                fieldName = cd.substring(start + 6, end);

            }

        }

        return fieldName;

    }

    /**

     * Creates a new {@link FileItem} instance.

     *

     * @param headers       A <code>Map</code> containing the HTTP request

     *                      headers.

     * @param isFormField   Whether or not this item is a form field, as

     *                      opposed to a file.

     *

     * @return A newly created <code>FileItem</code> instance.

     *

     * @exception FileUploadException if an error occurs.

     */

    protected FileItem createItem(Map /* String, String */ headers,

                                  boolean isFormField)

        throws FileUploadException

    {

        return getFileItemFactory().createItem(getFieldName(headers),

                getHeader(headers, CONTENT_TYPE),

                isFormField,

                getFileName(headers));

    }

    /**

     * <p> Parses the <code>header-part</code> and returns as key/value

     * pairs.

     *

     * <p> If there are multiple headers of the same names, the name

     * will map to a comma-separated list containing the values.

     *

     * @param headerPart The <code>header-part</code> of the current

     *                   <code>encapsulation</code>.

     *

     * @return A <code>Map</code> containing the parsed HTTP request headers.

     */

    protected Map /* String, String */ parseHeaders(String headerPart)

    {

        Map headers = new HashMap();

        char buffer[] = new char[MAX_HEADER_SIZE];

        boolean done = false;

        int j = 0;

        int i;

        String header, headerName, headerValue;

        try

        {

            while (!done)

            {

                i = 0;

                // Copy a single line of characters into the buffer,

                // omitting trailing CRLF.

                while (i < 2 || buffer[i - 2] != '\r' || buffer[i - 1] != '\n')

                {

                    buffer[i++] = headerPart.charAt(j++);

                }

                header = new String(buffer, 0, i - 2);

                if (header.equals(""))

                {

                    done = true;

                }

                else

                {

                    if (header.indexOf(':') == -1)

                    {

                        // This header line is malformed, skip it.

                        continue;

                    }

                    headerName = header.substring(0, header.indexOf(':'))

                        .trim().toLowerCase();

                    headerValue =

                        header.substring(header.indexOf(':') + 1).trim();

                    if (getHeader(headers, headerName) != null)

                    {

                        // More that one heder of that name exists,

                        // append to the list.

                        headers.put(headerName,

                                    getHeader(headers, headerName) + ','

                                        + headerValue);

                    }

                    else

                    {

                        headers.put(headerName, headerValue);

                    }