    001    // Copyright 2007, 2008 The Apache Software Foundation
    002    //
    003    // Licensed under the Apache License, Version 2.0 (the "License");
    004    // you may not use this file except in compliance with the License.
    005    // You may obtain a copy of the License at
    006    //
    007    //     http://www.apache.org/licenses/LICENSE-2.0
    008    //
    009    // Unless required by applicable law or agreed to in writing, software
    010    // distributed under the License is distributed on an "AS IS" BASIS,
    011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012    // See the License for the specific language governing permissions and
    013    // limitations under the License.
    014
    015    package org.apache.tapestry5.upload.services;
    016
    017    import org.apache.commons.fileupload.FileUploadException;
    018
    019    import javax.servlet.http.HttpServletRequest;
    020
    021    /**
    022     * Responsible for detecting and processing file upload requests, using Jakarta Commons FileUpload. Implementations of
    023     * this service typically use the threaded service lifecycle model.
    024     */
    025    public interface MultipartDecoder
    026    {
    027
    028        /**
    029         * @param parameterName Name of the query parameter associated with the uploaded file
    030         * @return a file upload with the given name, or null if no such file upload was in the request.
    031         */
    032        UploadedFile getFileUpload(String parameterName);
    033
    034        /**
    035         * Decodes the request, returning a new {@link javax.servlet.http.HttpServletRequest} implementation that will allow
    036         * access to the form fields submitted in the request (but omits uploaded files).
    037         *
    038         * @param request The incoming servlet request
    039         * @return decoded http request
    040         */
    041        HttpServletRequest decode(HttpServletRequest request);
    042
    043        /**
    044         * Returns the exception the occured during the file upload, or null if the processing of the multipart upload
    045         * stream was succesful.
    046         */
    047        FileUploadException getUploadException();
    048    }