Java tutorial
/* * 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.commons.fileupload.servlet; import java.io.IOException; import java.util.List; import javax.servlet.http.HttpServletRequest; import org.apache.commons.fileupload.FileItemFactory; import org.apache.commons.fileupload.FileItemIterator; import org.apache.commons.fileupload.FileUpload; import org.apache.commons.fileupload.FileUploadException; /** * <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.commons.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 * * @version $Id: ServletFileUpload.java 479484 2006-11-27 01:06:53Z jochen $ */ public class ServletFileUpload extends FileUpload { // ---------------------------------------------------------- Class methods /** * Utility method that determines whether the request contains multipart * content. * * @param request 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 request) { if (!"post".equals(request.getMethod().toLowerCase())) { return false; } String contentType = request.getContentType(); if (contentType == null) { return false; } if (contentType.toLowerCase().startsWith(MULTIPART)) { return true; } return false; } // ----------------------------------------------------------- Constructors /** * Constructs an uninitialised instance of this class. A factory must be * configured, using <code>setFileItemFactory()</code>, before attempting * to parse requests. * * @see FileUpload#FileUpload(FileItemFactory) */ public ServletFileUpload() { super(); } /** * Constructs an instance of this class which uses the supplied factory to * create <code>FileItem</code> instances. * * @see FileUpload#FileUpload() * @param fileItemFactory The factory to use for creating file items. */ public ServletFileUpload(FileItemFactory fileItemFactory) { super(fileItemFactory); } // --------------------------------------------------------- Public methods /** * Processes an <a href="http://www.ietf.org/rfc/rfc1867.txt">RFC 1867</a> * compliant <code>multipart/form-data</code> stream. * * @param request 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. * * @throws FileUploadException if there are problems reading/parsing * the request or storing files. */ public List /* FileItem */ parseRequest(HttpServletRequest request) throws FileUploadException { return parseRequest(new ServletRequestContext(request)); } /** * Processes an <a href="http://www.ietf.org/rfc/rfc1867.txt">RFC 1867</a> * compliant <code>multipart/form-data</code> stream. * * @param request The servlet request to be parsed. * * @return An iterator to instances of <code>FileItemStream</code> * parsed from the request, in the order that they were * transmitted. * * @throws FileUploadException if there are problems reading/parsing * the request or storing files. * @throws IOException An I/O error occurred. This may be a network * error while communicating with the client or a problem while * storing the uploaded content. */ public FileItemIterator getItemIterator(HttpServletRequest request) throws FileUploadException, IOException { return super.getItemIterator(new ServletRequestContext(request)); } }