Java tutorial
/* * $Id: MultiPartRequestWrapper.java 474787 2006-11-14 13:51:15Z husted $ * * 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.struts2.dispatcher.multipart; import java.io.File; import java.io.IOException; import java.util.ArrayList; import java.util.Collection; import java.util.Enumeration; import java.util.HashMap; import java.util.Map; import java.util.Vector; import javax.servlet.http.HttpServletRequest; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.struts2.dispatcher.StrutsRequestWrapper; /** * Parse a multipart request and provide a wrapper around the request. The parsing implementation used * depends on the <tt>struts.multipart.parser</tt> setting. It should be set to a class which * extends {@link org.apache.struts2.dispatcher.multipart.MultiPartRequest}. * <p/> * The <tt>struts.multipart.parser</tt> property should be set to <tt>jakarta</tt> for the * Jakarta implementation, <tt>pell</tt> for the Pell implementation and <tt>cos</tt> for the Jason Hunter * implementation. * <p/> * The files are uploaded when the object is instantiated. If there are any errors they are logged using * {@link #addError(String)}. An action handling a multipart form should first check {@link #hasErrors()} * before doing any other processing. * <p/> * An alternate implementation, PellMultiPartRequest, is provided as a plugin. * */ public class MultiPartRequestWrapper extends StrutsRequestWrapper { protected static final Log log = LogFactory.getLog(MultiPartRequestWrapper.class); Collection<String> errors; MultiPartRequest multi; /** * Process file downloads and log any errors. * * @param request Our HttpServletRequest object * @param saveDir Target directory for any files that we save * @param multiPartRequest Our MultiPartRequest object */ public MultiPartRequestWrapper(MultiPartRequest multiPartRequest, HttpServletRequest request, String saveDir) { super(request); multi = multiPartRequest; try { multi.parse(request, saveDir); for (Object o : multi.getErrors()) { String error = (String) o; addError(error); } } catch (IOException e) { addError("Cannot parse request: " + e.toString()); } } /** * Get an enumeration of the parameter names for uploaded files * * @return enumeration of parameter names for uploaded files */ public Enumeration<String> getFileParameterNames() { if (multi == null) { return null; } return multi.getFileParameterNames(); } /** * Get an array of content encoding for the specified input field name or <tt>null</tt> if * no content type was specified. * * @param name input field name * @return an array of content encoding for the specified input field name */ public String[] getContentTypes(String name) { if (multi == null) { return null; } return multi.getContentType(name); } /** * Get a {@link java.io.File[]} for the given input field name. * * @param fieldName input field name * @return a File[] object for files associated with the specified input field name */ public File[] getFiles(String fieldName) { if (multi == null) { return null; } return multi.getFile(fieldName); } /** * Get a String array of the file names for uploaded files * * @param fieldName Field to check for file names. * @return a String[] of file names for uploaded files */ public String[] getFileNames(String fieldName) { if (multi == null) { return null; } return multi.getFileNames(fieldName); } /** * Get the filename(s) of the file(s) uploaded for the given input field name. * Returns <tt>null</tt> if the file is not found. * * @param fieldName input field name * @return the filename(s) of the file(s) uploaded for the given input field name or * <tt>null</tt> if name not found. */ public String[] getFileSystemNames(String fieldName) { if (multi == null) { return null; } return multi.getFilesystemName(fieldName); } /** * @see javax.servlet.http.HttpServletRequest#getParameter(String) */ public String getParameter(String name) { return ((multi == null) || (multi.getParameter(name) == null)) ? super.getParameter(name) : multi.getParameter(name); } /** * @see javax.servlet.http.HttpServletRequest#getParameterMap() */ public Map getParameterMap() { Map<String, String[]> map = new HashMap<String, String[]>(); Enumeration enumeration = getParameterNames(); while (enumeration.hasMoreElements()) { String name = (String) enumeration.nextElement(); map.put(name, this.getParameterValues(name)); } return map; } /** * @see javax.servlet.http.HttpServletRequest#getParameterNames() */ public Enumeration getParameterNames() { if (multi == null) { return super.getParameterNames(); } else { return mergeParams(multi.getParameterNames(), super.getParameterNames()); } } /** * @see javax.servlet.http.HttpServletRequest#getParameterValues(String) */ public String[] getParameterValues(String name) { return ((multi == null) || (multi.getParameterValues(name) == null)) ? super.getParameterValues(name) : multi.getParameterValues(name); } /** * Returns <tt>true</tt> if any errors occured when parsing the HTTP multipart request, <tt>false</tt> otherwise. * * @return <tt>true</tt> if any errors occured when parsing the HTTP multipart request, <tt>false</tt> otherwise. */ public boolean hasErrors() { return !((errors == null) || errors.isEmpty()); } /** * Returns a collection of any errors generated when parsing the multipart request. * * @return the error Collection. */ public Collection<String> getErrors() { return errors; } /** * Adds an error message. * * @param anErrorMessage the error message to report. */ protected void addError(String anErrorMessage) { if (errors == null) { errors = new ArrayList<String>(); } errors.add(anErrorMessage); } /** * Merges 2 enumeration of parameters as one. * * @param params1 the first enumeration. * @param params2 the second enumeration. * @return a single Enumeration of all elements from both Enumerations. */ protected Enumeration mergeParams(Enumeration params1, Enumeration params2) { Vector temp = new Vector(); while (params1.hasMoreElements()) { temp.add(params1.nextElement()); } while (params2.hasMoreElements()) { temp.add(params2.nextElement()); } return temp.elements(); } }