Java tutorial
/* 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 org.activiti.explorer.ui.custom; import java.io.ByteArrayOutputStream; import java.io.OutputStream; import java.util.Collection; import org.activiti.explorer.ExplorerApp; import org.activiti.explorer.Messages; import org.activiti.explorer.NotificationManager; import org.activiti.explorer.util.StringUtil; import com.vaadin.ui.Upload; import com.vaadin.ui.Upload.ProgressListener; import com.vaadin.ui.Upload.Receiver; import com.vaadin.ui.Upload.StartedEvent; import com.vaadin.ui.Upload.StartedListener; /** * Generic {@link Receiver} for an {@link Upload} component. * Stores the bytes in-memory, so be careful to limit the size of the uploads. * * @author Joram Barrez */ public class InMemoryUploadReceiver implements Receiver, StartedListener, ProgressListener { private static final long serialVersionUID = 1L; protected NotificationManager notificationManager; protected Upload upload; protected boolean interrupted; protected String fileName; protected String mimeType; protected long maxFileSize; protected ByteArrayOutputStream outputStream; protected Collection<String> acceptedMimeTypes; /** * @param upload The component that will serve this receiver * @param maxFileSize The maximum size of files that will be accepted (in bytes). -1 in case of no limit. */ public InMemoryUploadReceiver(Upload upload, long maxFileSize) { this.upload = upload; this.maxFileSize = maxFileSize; this.notificationManager = ExplorerApp.get().getNotificationManager(); upload.setReceiver(this); upload.addListener((StartedListener) this); upload.addListener((ProgressListener) this); } public OutputStream receiveUpload(String filename, String mimeType) { this.fileName = filename; this.mimeType = mimeType; this.outputStream = new ByteArrayOutputStream(); return outputStream; } public void uploadStarted(StartedEvent event) { checkFileSize(event.getContentLength()); if (!interrupted) { // upload can be interrupted by invalid file size checkMimeType(event.getMIMEType()); } } public void updateProgress(long readBytes, long contentLength) { if (contentLength == -1) { // Older browsers don't support getting the filesize checkFileSize(readBytes); } else { checkFileSize(contentLength); } } public byte[] getBytes() { return outputStream.toByteArray(); } public String getFileName() { return fileName; } public String getMimeType() { return mimeType; } public boolean isInterruped() { return interrupted; } protected void checkFileSize(long receivedLength) { if (receivedLength > maxFileSize) { interrupt(); notificationManager.showWarningNotification(Messages.UPLOAD_FAILED, Messages.UPLOAD_LIMIT, maxFileSize / 1024 + "kb"); } } protected void checkMimeType(String mimeType) { if (acceptedMimeTypes != null && !acceptedMimeTypes.contains(mimeType)) { interrupt(); notificationManager.showWarningNotification(Messages.UPLOAD_FAILED, Messages.UPLOAD_INVALID_MIMETYPE, StringUtil.toReadableString(acceptedMimeTypes)); } } protected void interrupt() { upload.interruptUpload(); interrupted = true; } /** * By default, all mime types are accepted. * By providing a set of mimetypes, the receiver will only work with the given mimetypes */ public void setAcceptedMimeTypes(Collection<String> acceptedMimeTypes) { this.acceptedMimeTypes = acceptedMimeTypes; } public void reset() { interrupted = false; outputStream = null; fileName = null; mimeType = null; } }