Java tutorial
package org.sigmah.server.servlet; /* * #%L * Sigmah * %% * Copyright (C) 2010 - 2016 URD * %% * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as * published by the Free Software Foundation, either version 3 of the * License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public * License along with this program. If not, see * <http://www.gnu.org/licenses/gpl-3.0.html>. * #L% */ import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.InputStream; import java.util.HashMap; import javax.persistence.EntityManager; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.fileupload.FileItemIterator; import org.apache.commons.fileupload.FileItemStream; import org.apache.commons.fileupload.servlet.ServletFileUpload; import org.apache.commons.fileupload.util.Streams; import org.sigmah.server.servlet.base.AbstractServlet; import org.sigmah.server.servlet.base.ServletExecutionContext; import org.sigmah.server.servlet.exporter.models.CategoryTypeHandler; import org.sigmah.server.servlet.exporter.models.ModelHandler; import org.sigmah.server.servlet.exporter.models.OrgUnitModelHandler; import org.sigmah.server.servlet.exporter.models.ProjectModelHandler; import org.sigmah.server.servlet.exporter.models.ProjectReportModelHandler; import org.sigmah.shared.dto.referential.ProjectModelType; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.google.inject.Inject; import com.google.inject.Injector; import com.google.inject.Singleton; import java.io.IOException; import java.nio.file.StandardCopyOption; import java.util.Map; import org.apache.commons.fileupload.FileUploadException; import org.sigmah.server.file.FileStorageProvider; /** * Servlet handling the import of model and values. * * @author Mehdi Benabdeslam (mehdi.benabdeslam@netapsys.fr) v2.0 * @author Raphal Calabro (rcalabro@ideia.fr) */ @Singleton public class ImportServlet extends AbstractServlet { /** * Serial */ private static final long serialVersionUID = 3249000141532724402L; /** * Logger. */ @SuppressWarnings("unused") private static final Logger LOG = LoggerFactory.getLogger(ImportServlet.class); private static final long MAXIMUM_FILE_SIZE = 2097152; // 2 Mo /** * Injected application injector. */ private final Injector injector; /** * Injected application {@link FileStorageProvider}. */ private final FileStorageProvider fileStorageProvider; @Inject public ImportServlet(Injector injector, FileStorageProvider fileStorageProvider) { this.injector = injector; this.fileStorageProvider = fileStorageProvider; } /** * Import Report Model * * @param request * @param response * @param context * @throws Exception */ public void importReportModel(final HttpServletRequest request, final HttpServletResponse response, final ServletExecutionContext context) throws Exception { runImport(new ProjectReportModelHandler(), request, response, context); } /** * import Orgunit Model * * @param request * @param response * @param context * @throws Exception */ public void importOrgUnitModel(final HttpServletRequest request, final HttpServletResponse response, final ServletExecutionContext context) throws Exception { runImport(new OrgUnitModelHandler(), request, response, context); } /** * import Project Model * * @param request * @param response * @param context * @throws Exception */ public void importProjectModel(final HttpServletRequest request, final HttpServletResponse response, final ServletExecutionContext context) throws Exception { runImport(new ProjectModelHandler(), request, response, context); } /** * import Category model * * @param request * @param response * @param context * @throws Exception */ public void importCategoryModel(final HttpServletRequest request, final HttpServletResponse response, final ServletExecutionContext context) throws Exception { runImport(new CategoryTypeHandler(), request, response, context); } /** * Run Import model format dat * * @param handler * @param request * @param response * @param context * @throws Exception */ public void runImport(final ModelHandler handler, final HttpServletRequest request, final HttpServletResponse response, final ServletExecutionContext context) throws Exception { final HashMap<String, String> properties = new HashMap<String, String>(); final byte[] data; try { data = readFileAndProperties(request, properties); } catch (FileUploadException | IOException ex) { LOG.error("Error while receiving a serialized model.", ex); throw ex; } if (data != null) { // A file has been received if (handler != null) { if (handler instanceof ProjectModelHandler) { final String projectModelTypeAsString = properties.get("project-model-type"); try { final ProjectModelType projectModelType = ProjectModelType .valueOf(projectModelTypeAsString); ((ProjectModelHandler) handler).setProjectModelType(projectModelType); } catch (IllegalArgumentException e) { LOG.debug("Bad value for project model type: " + projectModelTypeAsString, e); } } final ByteArrayInputStream inputStream = new ByteArrayInputStream(data); try { handler.importModel(inputStream, injector.getInstance(EntityManager.class), context.getUser()); } catch (Exception ex) { LOG.error("Model import error, ", ex); throw ex; } } else { LOG.warn("The asked model type doesn't have any handler registered."); } } else { LOG.warn("No file has been received."); } } /** * Store the uploaded file on the disk and return the identifier of the * file to the user. * * @param request Http request. * @param response Http response. * @param context Execution context. * @throws FileUploadException If an error occured while reading the http request. * @throws IOException If the file could not be written on the server. */ public void storeFile(final HttpServletRequest request, final HttpServletResponse response, final ServletExecutionContext context) throws FileUploadException, IOException { final HashMap<String, String> properties = new HashMap<String, String>(); final byte[] data; try { data = readFileAndProperties(request, properties); } catch (FileUploadException | IOException ex) { LOG.error("Error while receiving a file containing values.", ex); throw ex; } if (data != null) { // A file has been received final String uniqueFileId = FileServlet.generateUniqueName(); final long length = fileStorageProvider.copy(new ByteArrayInputStream(data), uniqueFileId, StandardCopyOption.REPLACE_EXISTING); if (length > 0) { response.setContentType("text/html"); response.getWriter().write(uniqueFileId); } } } private byte[] readFileAndProperties(final HttpServletRequest request, final Map<String, String> properties) throws FileUploadException, IOException { byte[] data = null; final ServletFileUpload fileUpload = new ServletFileUpload(); final FileItemIterator iterator = fileUpload.getItemIterator(request); // Iterating on the fields sent into the request while (iterator.hasNext()) { final FileItemStream item = iterator.next(); final String name = item.getFieldName(); final InputStream stream = item.openStream(); if (item.isFormField()) { final String value = Streams.asString(stream); LOG.debug("field '" + name + "' = '" + value + '\''); // The current field is a property properties.put(name, value); } else { // The current field is a file LOG.debug("field '" + name + "' (FILE)"); final ByteArrayOutputStream serializedData = new ByteArrayOutputStream(); long dataSize = 0L; int b = stream.read(); while (b != -1 && dataSize < MAXIMUM_FILE_SIZE) { serializedData.write(b); dataSize++; b = stream.read(); } stream.close(); data = serializedData.toByteArray(); } } return data; } }