Java tutorial
/*** * Copyright (c) 2009 Caelum - www.caelum.com.br/opensource * All rights reserved. * * Licensed 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 br.com.caelum.vraptor.observer.upload; import static com.google.common.base.Strings.isNullOrEmpty; import static org.slf4j.LoggerFactory.getLogger; import java.io.IOException; import java.io.UnsupportedEncodingException; import java.util.Collection; import java.util.List; import javax.enterprise.context.ApplicationScoped; import javax.enterprise.event.Observes; import javax.servlet.ServletRequest; import javax.servlet.http.HttpServletRequest; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.FileUploadBase.SizeLimitExceededException; import org.apache.commons.fileupload.FileUploadException; import org.apache.commons.fileupload.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload; import org.apache.commons.io.FilenameUtils; import org.slf4j.Logger; import br.com.caelum.vraptor.events.ControllerFound; import br.com.caelum.vraptor.http.InvalidParameterException; import br.com.caelum.vraptor.http.MutableRequest; import br.com.caelum.vraptor.validator.I18nMessage; import br.com.caelum.vraptor.validator.Validator; import com.google.common.collect.HashMultiset; import com.google.common.collect.LinkedListMultimap; import com.google.common.collect.Multimap; import com.google.common.collect.Multiset; /** * A multipart observer based on Apache Commons Upload. Provided parameters are injected through * {@link HttpServletRequest#setAttribute(String, Object)} and uploaded files are made available through. * * @author Guilherme Silveira * @author Otvio Scherer Garcia * @author Rodrigo Turini */ @ApplicationScoped public class CommonsUploadMultipartObserver { private static final Logger logger = getLogger(CommonsUploadMultipartObserver.class); public void upload(@Observes ControllerFound event, MutableRequest request, MultipartConfig config, Validator validator) { if (!ServletFileUpload.isMultipartContent(request)) { return; } logger.info("Request contains multipart data. Try to parse with commons-upload."); final Multiset<String> indexes = HashMultiset.create(); final Multimap<String, String> params = LinkedListMultimap.create(); ServletFileUpload uploader = createServletFileUpload(config); uploader.setSizeMax(config.getSizeLimit()); uploader.setFileSizeMax(config.getFileSizeLimit()); try { final List<FileItem> items = uploader.parseRequest(request); logger.debug("Found {} attributes in the multipart form submission. Parsing them.", items.size()); for (FileItem item : items) { String name = item.getFieldName(); name = fixIndexedParameters(name, indexes); if (item.isFormField()) { logger.debug("{} is a field", name); params.put(name, getValue(item, request)); } else if (isNotEmpty(item)) { logger.debug("{} is a file", name); processFile(item, name, request); } else { logger.debug("A file field is empty: {}", item.getFieldName()); } } for (String paramName : params.keySet()) { Collection<String> paramValues = params.get(paramName); request.setParameter(paramName, paramValues.toArray(new String[paramValues.size()])); } } catch (final SizeLimitExceededException e) { reportSizeLimitExceeded(e, validator); } catch (FileUploadException e) { reportFileUploadException(e, validator); } } private boolean isNotEmpty(FileItem item) { return item.getName().length() > 0; } /** * This method is called when the {@link SizeLimitExceededException} was thrown. */ protected void reportSizeLimitExceeded(final SizeLimitExceededException e, Validator validator) { validator.add(new I18nMessage("upload", "file.limit.exceeded", e.getActualSize(), e.getPermittedSize())); logger.warn("The file size limit was exceeded. Actual {} permitted {}", e.getActualSize(), e.getPermittedSize()); } protected void reportFileUploadException(FileUploadException e, Validator validator) { validator.add(new I18nMessage("upload", "file.upload.exception")); logger.warn("There was some problem parsing this multipart request, " + "or someone is not sending a RFC1867 compatible multipart request.", e); } protected void processFile(FileItem item, String name, MutableRequest request) { try { String fileName = FilenameUtils.getName(item.getName()); UploadedFile upload = new DefaultUploadedFile(item.getInputStream(), fileName, item.getContentType(), item.getSize()); request.setParameter(name, name); request.setAttribute(name, upload); logger.debug("Uploaded file: {} with {}", name, upload); } catch (IOException e) { throw new InvalidParameterException("Cant parse uploaded file " + item.getName(), e); } } protected ServletFileUpload createServletFileUpload(MultipartConfig config) { DiskFileItemFactory factory = new DiskFileItemFactory(); factory.setRepository(config.getDirectory()); logger.debug("Using repository {} for file upload", factory.getRepository()); return new ServletFileUpload(factory); } protected String getValue(FileItem item, ServletRequest request) { String encoding = request.getCharacterEncoding(); if (!isNullOrEmpty(encoding)) { try { return item.getString(encoding); } catch (UnsupportedEncodingException e) { logger.warn("Request have an invalid encoding. Ignoring it"); } } return item.getString(); } protected String fixIndexedParameters(String name, Multiset<String> indexes) { if (name.contains("[]")) { String newName = name.replace("[]", "[" + (indexes.count(name)) + "]"); indexes.add(name); logger.debug("{} was renamed to {}", name, newName); return newName; } return name; } }