FTP server is no longer used for thumbnails. Everything is stored on the storage service. Waiting for ticket #5799 to be completed to speed up the generic thumbnails retrieval

git-svn-id: https://svn.research-infrastructures.eu/d4science/gcube/trunk/portlets/user/share-updates@134370 82a268e6-3cf1-43bd-a215-b396298e98cf

distro/changelog.xml

@@ -1,9 +1,16 @@
 <ReleaseNotes>
+	<Changeset component="org.gcube.portlets-user.shareupdates.2-2-0"
+		date="2016-12-02">
+		<Change>Removed asl session dependency</Change>
+		<Change>Thumbnails are no longer stored on the FTP server. Storage
+			service is used</Change>
+	</Changeset>
 	<Changeset component="org.gcube.portlets-user.shareupdates.2-1-0"
 		date="2016-09-29">
-		<Change>updated opengraph checkURL for getting images in case of HTTP redirect permanently is encountered</Change>
+		<Change>updated opengraph checkURL for getting images in case of HTTP
+			redirect permanently is encountered
+		</Change>
 	</Changeset>
-
 	<Changeset component="org.gcube.portlets-user.shareupdates.2-0-0"
 		date="2016-06-29">
 		<Change>Updated to Liferay 6.2.5</Change>
@@ -24,7 +31,8 @@
 	<Changeset component="org.gcube.portlets-user.shareupdates.1-8-0"
 		date="2015-07-06">
 		<Change>made notification to members option configurable as default,
-			see Feature #121</Change>
+			see Feature #121
+		</Change>
 	</Changeset>
 	<Changeset component="org.gcube.portlets-user.shareupdates.1-7-0"
 		date="2015-05-27">

pom.xml

@@ -97,7 +97,7 @@
 		<dependency>
 			<groupId>org.gcube.core</groupId>
 			<artifactId>common-scope-maps</artifactId>
-			<scope>compile</scope>
+			<scope>provided</scope>
 		</dependency>
 		<dependency>
 			<groupId>org.gcube.portlets.widgets</groupId>
@@ -232,10 +232,12 @@
 		<dependency>
 			<groupId>org.slf4j</groupId>
 			<artifactId>slf4j-log4j12</artifactId>
+			<scope>provided</scope>
 		</dependency>
 		<dependency>
 			<groupId>org.slf4j</groupId>
 			<artifactId>slf4j-api</artifactId>
+			<scope>provided</scope>
 		</dependency>
 	</dependencies>
 	<build>

src/main/java/org/gcube/portlets/user/shareupdates/server/FilePreviewer.java

@@ -8,20 +8,27 @@ import java.awt.image.BufferedImage;
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.File;
+import java.io.FileOutputStream;
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.RandomAccessFile;
+import java.net.HttpURLConnection;
+import java.net.URL;
 import java.nio.ByteBuffer;
 import java.nio.channels.FileChannel;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Iterator;
+import java.util.UUID;
 
 import javax.imageio.ImageIO;
 import javax.imageio.ImageReader;
 import javax.imageio.stream.ImageInputStream;
+import javax.servlet.ServletContext;
 
 import net.coobird.thumbnailator.Thumbnails;
 
+import org.apache.commons.fileupload.util.Streams;
 import org.apache.pdfbox.pdmodel.PDDocument;
 import org.apache.pdfbox.util.PDFTextStripper;
 import org.apache.tika.config.TikaConfig;
@@ -29,8 +36,7 @@ import org.apache.tika.detect.Detector;
 import org.apache.tika.io.TikaInputStream;
 import org.apache.tika.metadata.Metadata;
 import org.apache.tika.mime.MediaType;
-import org.gcube.applicationsupportlayer.social.storage.FTPManager;
+import org.gcube.contentmanagement.blobstorage.service.IClient;
-import org.gcube.portal.databook.shared.ImageType;
 import org.gcube.portlets.user.shareupdates.shared.LinkPreview;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -39,35 +45,36 @@ import com.sun.pdfview.PDFFile;
 import com.sun.pdfview.PDFPage;
 import com.sun.pdfview.PDFParseException;
 /**
- * 
- * @author Massimiliano Assante, ISTI-CNR
- * 
  * Parse files and returns an image preview plus description
- *
+ * @author Massimiliano Assante, ISTI-CNR
  */
 public class FilePreviewer {
-	private static Logger _log = LoggerFactory.getLogger(FilePreviewer.class);
 
-	private static final String PDF_DEFAULT_IMAGE = "default/pdf.png";
+	private static final Logger _log = LoggerFactory.getLogger(FilePreviewer.class);
-	private static final String GENERICFILE_DEFAULT_IMAGE = "default/default_generic.png";
+	private static final String UPLOAD_LOCATION_LOCAL = System.getProperty("java.io.tmpdir");
+	public static final String DIR_STORAGE_DEFAULT_ICONS = "default-icons-directory"; // to be append to UPLOAD_DIR
+
 	/**
 	 * these are the extension for which I have an icon image preview
 	 */
 	private static final String[] handledextensionImages = {"css", "csv", "doc", "docx", "java", "mdb", "mp3", "pdf", "ppt", "pptx", "psd", "rar", "tex", "txt", "xls", "xlsx", "zip"};
 
-	private static FTPManager getFTPManager() {
-		return FTPManager.getInstance();
-	}
-
 	/**
 	 * 
 	 * @param fileNameLabel thename of the file
 	 * @param path2Pdf the path of the pdf file
 	 * @param httpUrl the http url where the file is reachable at
+	 * @param storageClient 
 	 * @return
 	 * @throws Exception
 	 */
-	protected static LinkPreview getPdfPreview(String fileName, String path2Pdf, String httpUrl, String mimeType) throws Exception {		
+	protected static LinkPreview getPdfPreview(
+			String fileName, 
+			String path2Pdf, 
+			String httpUrl, 
+			String mimeType, 
+			IClient sClient,
+			ServletContext sContext) throws Exception {		
 		ArrayList<String> imagesUrl = new ArrayList<String>();
 		//description
 		String desc = null;
@@ -90,8 +97,7 @@ public class FilePreviewer {
 		} catch (PDFParseException ex) {
 			raf.close();
 			_log.error("PDF Parse exception, returning default pdf image");
-
+			imagesUrl.add(getDefaultIconUrl(sClient, IconFileNames.PDF.getFileName(), sContext));
-			imagesUrl.add(getFTPManager().getBaseURL()+PDF_DEFAULT_IMAGE);
 			return new LinkPreview(fileName, desc, httpUrl, mimeType, imagesUrl);
 		}
 		PDFPage page = pdf.getPage(0);
@@ -104,11 +110,8 @@ public class FilePreviewer {
 
 		// create the image
 		Rectangle rect = new Rectangle(0, 0, width, height);
-
 		BufferedImage bufferedImage = new BufferedImage(scaledWidth, scaledHeight, BufferedImage.TYPE_INT_RGB);
-
 		Image image = page.getImage(scaledWidth, scaledHeight, rect, null, true, true);                    
-
 		Graphics2D bufImageGraphics = bufferedImage.createGraphics();
 		bufImageGraphics.drawImage(image, 0, 0, scaledWidth, scaledHeight, null);
 
@@ -118,9 +121,14 @@ public class FilePreviewer {
 		raf.close();
 
 		if (result) {
-			String httpLink = getFTPManager().uploadImageOnFTPServer(new ByteArrayInputStream(out.toByteArray()), ImageType.JPG);
+			try{
-			_log.debug("PDF thumbnail available at: " + httpLink);
+				String storagehttpLink = syncUploadThumbnailStorage(new ByteArrayInputStream(out.toByteArray()), sClient, "thumbnail_" + fileName);
-			imagesUrl.add(httpLink);
+				imagesUrl.add(storagehttpLink);
+				_log.debug("PDF thumbnail available at: " + storagehttpLink);
+			}catch(Exception e){
+				_log.error("Failed to create a thumbnail for the preview ...");
+				imagesUrl.add(getDefaultIconUrl(sClient, IconFileNames.PDF.getFileName(), sContext));
+			} 
 			return new LinkPreview(fileName, desc, httpUrl, mimeType, imagesUrl);
 		}
 		else
@@ -134,7 +142,7 @@ public class FilePreviewer {
 	 * @return
 	 * @throws Exception
 	 */
-	protected static LinkPreview getImagePreview(String fileName, String path2Image, String httpUrl, String mimeType) {
+	protected static LinkPreview getImagePreview(String fileName, String path2Image, String httpUrl, String mimeType, IClient sClient, ServletContext sContext) {
 		ArrayList<String> imagesUrl = new ArrayList<String>();
 
 		Dimension dim;
@@ -152,13 +160,15 @@ public class FilePreviewer {
 			.width(80)
 			.outputFormat("jpg")
 			.toOutputStream(out);
+
+			String storagehttpLink = syncUploadThumbnailStorage(new ByteArrayInputStream(out.toByteArray()), sClient, "thumbnail_" + fileName);
+			_log.debug("Image thumbnail available at: " + storagehttpLink);
+			imagesUrl.add(storagehttpLink);
+		}catch (IOException e) {
+			_log.error("Failed to get a preview... Using generic image");
+			imagesUrl.add(getDefaultIconUrl(sClient, IconFileNames.IMAGE_GENERIC.getFileName(), sContext));
 		}
-		catch (IOException e) {
+
-			e.printStackTrace();
-		}
-		String httpLink = getFTPManager().uploadImageOnFTPServer(new ByteArrayInputStream(out.toByteArray()), ImageType.JPG);
-		_log.debug("\nFlushed, Image thumbnail available at: " + httpLink);
-		imagesUrl.add(httpLink);
 		return new LinkPreview(fileName, desc, httpUrl, mimeType, imagesUrl);
 	}
 
@@ -170,20 +180,26 @@ public class FilePreviewer {
 	 * @return
 	 * @throws Exception
 	 */
-	protected static LinkPreview getUnhandledTypePreview(String fileName, String path2Pdf, String httpUrl, String mimeType) throws Exception {		
+	protected static LinkPreview getUnhandledTypePreview(
+			String fileName, 
+			String path2Pdf, 
+			String httpUrl, 
+			String mimeType, 
+			IClient sClient,
+			ServletContext sContext) throws Exception {		
 
 		ArrayList<String> imagesUrl = new ArrayList<String>();
 		String extension = getExtension(fileName);
 		//no description
 		String desc = "";
 		if (extension == null)
-			imagesUrl.add(getFTPManager().getBaseURL()+GENERICFILE_DEFAULT_IMAGE);
+			imagesUrl.add(getDefaultIconUrl(sClient, IconFileNames.GENERIC.getFileName(), sContext));
 		else {
 			int foundIndex = Arrays.binarySearch(handledextensionImages, extension);
 			if (foundIndex < 0)
-				imagesUrl.add(getFTPManager().getBaseURL()+GENERICFILE_DEFAULT_IMAGE);
+				imagesUrl.add(getDefaultIconUrl(sClient, IconFileNames.GENERIC.getFileName(), sContext));
 			else
-				imagesUrl.add(getFTPManager().getBaseURL()+"default/"+extension+".png");
+				imagesUrl.add(getDefaultIconUrl(sClient, extension+".png", sContext));
 		}
 		return new LinkPreview(fileName, desc, httpUrl, mimeType, imagesUrl);
 	}
@@ -254,4 +270,148 @@ public class FilePreviewer {
 		MediaType mediaType = detector.detect(stream, metadata);
 		return mediaType.getBaseType().toString();
 	}
+
+	/**
+	 * Same as above, but having as input an inputstream object
+	 * @param is
+	 * @param filenameWithExtension
+	 * @return
+	 * @throws IOException
+	 */
+	protected static String getMimeType(InputStream is, String filenameWithExtension) throws IOException {
+		TikaConfig config = TikaConfig.getDefaultConfig();
+		Detector detector = config.getDetector();
+		TikaInputStream stream = TikaInputStream.get(is);
+		Metadata metadata = new Metadata();
+		metadata.add(Metadata.RESOURCE_NAME_KEY, filenameWithExtension);
+		MediaType mediaType = detector.detect(stream, metadata);
+		return mediaType.getBaseType().toString();
+	}
+
+	/**
+	 * Upload a thumbnail on the storage and returns the http url. The operation is synchronous 
+	 * @param sClient 
+	 * @param byteArrayInputStream 
+	 * @return http url of the thumbnail
+	 */
+	protected static String syncUploadThumbnailStorage(ByteArrayInputStream byteArrayInputStream, IClient sClient, String thumbnailFileName){
+		try{
+			// a random remote folder/file on the storage for the thumbnail
+			String randomUploadFolderName = UUID.randomUUID().toString();
+			String remoteFilePath = ShareUpdateServiceImpl.UPLOAD_DIR + "/" + randomUploadFolderName + "/" + thumbnailFileName;
+			String thumbnailMime = getMimeType(byteArrayInputStream, null);
+			sClient.put(true, thumbnailMime).LFile(byteArrayInputStream).RFile(remoteFilePath);
+			return sClient.getHttpUrl(true).RFile(remoteFilePath);
+		}catch(Exception e){
+			_log.error("Failed to upload thumbnail on storage...");
+			return null;
+		}
+	}
+
+	/**
+	 * Check if a resource at a given url exists or not. If it exists, create a file in the temp dir
+	 * of the tomcat. Files and folers are deleted on exit.
+	 * @param urlThumbnail
+	 * @return
+	 */
+	public static File storeAndGetFile(String urlThumbnail){
+		try {
+			HttpURLConnection.setFollowRedirects(true);
+			HttpURLConnection con =
+					(HttpURLConnection) new URL(urlThumbnail).openConnection();
+			con.setRequestMethod("HEAD"); // body is not needed yet
+			if(con.getResponseCode() == HttpURLConnection.HTTP_OK){
+
+				//generate the random dir 
+				File theRandomDir = new File(UPLOAD_LOCATION_LOCAL + File.separator + UUID.randomUUID().toString());
+				theRandomDir.mkdir();
+				theRandomDir.deleteOnExit();
+				_log.debug("Created temp upload directory in: " + theRandomDir);
+
+				// generate a random file name and create it under the randomDir
+				File file = new File(theRandomDir, UUID.randomUUID().toString().substring(0, 10)); 
+				file.deleteOnExit();
+
+				//Get the inputstream and copy there
+				URL url = new URL(urlThumbnail);
+				Streams.copy(url.openStream(), new FileOutputStream(file), true);
+				_log.debug("File is at " + file.getAbsolutePath());
+
+				return file;
+			}else
+				return null;
+		}
+		catch (Exception e) {
+			_log.error("The resource at url " + urlThumbnail + " doesn't exist");
+			return null;
+		}
+	}
+
+	/**
+	 * When a link preview needs to be saved, the method save the thumbnail on the storage no longer using the external url
+	 * @param urlThumbnail
+	 * @return the url of the thumbnail saved on the storage or null in case of error
+	 */
+	public static String getThumbnailFromUrl(String urlThumbnail, IClient sClient, ServletContext sContext) {
+		File localFile;
+		if((localFile = storeAndGetFile(urlThumbnail)) != null){
+			String mimeType = null;
+			try {
+				mimeType = FilePreviewer.getMimeType(localFile, localFile.getName());
+				String thumbnailUrlStorage = null;
+				switch(mimeType){
+				case "image/png":
+				case "image/gif":
+				case "image/tiff":
+				case "image/jpg":
+				case "image/jpeg":
+				case "image/bmp":
+					thumbnailUrlStorage = getImagePreview(localFile.getName(), localFile.getAbsolutePath(), null, mimeType, sClient, sContext).getImageUrls().get(0);
+					break;
+				default: break;
+				}
+				return thumbnailUrlStorage;
+			} catch (IOException e) {
+				_log.error("Error while saving thumbnail on ftp", e);
+			}
+
+		}else
+			_log.warn("the file at url " + urlThumbnail + " doesn't exist");
+
+		return null;
+	}
+
+	/**
+	 * When the preview methods fail to create a thumbnail and one of the "default icons" needs to be used,
+	 * the method retrieve the url of these files from the storage. In case the icon is missing, it upload the file too on the storage
+	 * before returning.
+	 * @param storage
+	 * @return
+	 */
+	private static String getDefaultIconUrl(IClient sClient, String iconFile, ServletContext sContext){
+
+		try{
+			//TODO do I need to download the whole stream?!
+			String iconPathOnStorage = ShareUpdateServiceImpl.UPLOAD_DIR + "/" + FilePreviewer.DIR_STORAGE_DEFAULT_ICONS + "/" + iconFile;
+			_log.debug("looking for remote file at relative url " + iconPathOnStorage);
+
+			InputStream inputStream = sClient.get().RFileAsInputStream(iconPathOnStorage);
+			if(inputStream == null){
+				_log.info("Ok, the default icon was not on the storage.. going to put it there");
+				InputStream localInputStream = sContext.getResourceAsStream("/images/default/" + iconFile);
+				if(localInputStream != null){
+					sClient.put(true).LFile(localInputStream).RFile(iconPathOnStorage);
+					_log.info("Request for upload started for file " + iconPathOnStorage + ", trying to get the http url");
+					return sClient.getHttpUrl(true).RFile(iconPathOnStorage);
+				}else{
+					_log.warn("Failed to get the inputstream of the icon " + iconFile + " form the subpath /images/default/");
+					return null;
+				}
+			}else
+				return sClient.getHttpUrl(true).RFile(iconPathOnStorage);
+		}catch(Exception e){
+			_log.error("Something went wrong with the storage for the default image.. returning null", e);
+		}
+		return null;
+	}
 }

src/main/java/org/gcube/portlets/user/shareupdates/server/IconFileNames.java

@@ -0,0 +1,38 @@
+package org.gcube.portlets.user.shareupdates.server;
+
+/**
+ * Icons type
+ * @author Costantino Perciante at ISTI-CNR 
+ * (costantino.perciante@isti.cnr.it)
+ */
+public enum IconFileNames {
+
+	GENERIC("default_generic.png"),
+	IMAGE_GENERIC("default_image.png"),
+	DOCX("docx.png"),
+	PPTX("pptx.png"),
+	PDF("pdf.png"),
+	RAR("rar.png"),
+	ZIP("zip.png"),
+	XLS("xls.png"),
+	CSS("css.png"),
+	CSV("csv.png"),
+	DOC("doc.png"),
+	JAVA("java.png"),
+	MDB("mdb.png"),
+	MP3("mp3.png"),
+	PSD("psd.png"),
+	TEX("tex.png"),
+	PPT("ppt.png"),
+	XLSX("xlsx.png");
+
+	private String fileName;
+
+	IconFileNames(String fileName){
+		this.fileName = fileName;
+	}
+	
+	public String getFileName(){
+		return this.fileName;
+	}
+}

src/main/java/org/gcube/portlets/user/shareupdates/server/ShareUpdateServiceImpl.java

@@ -1,7 +1,6 @@
 package org.gcube.portlets.user.shareupdates.server;
 
 import java.io.File;
-import java.io.FileOutputStream;
 import java.io.IOException;
 import java.net.HttpURLConnection;
 import java.net.MalformedURLException;
@@ -19,7 +18,6 @@ import java.util.UUID;
 
 import javax.net.ssl.HttpsURLConnection;
 
-import org.apache.commons.fileupload.util.Streams;
 import org.apache.commons.validator.routines.UrlValidator;
 import org.gcube.applicationsupportlayer.social.ApplicationNotificationsManager;
 import org.gcube.applicationsupportlayer.social.NotificationsManager;
@@ -84,12 +82,7 @@ public class ShareUpdateServiceImpl extends RemoteServiceServlet implements	Shar
 	private static final String STORAGE_OWNER = "gCubeSocialFramework";
 	public static final String UPLOAD_DIR = "/social-framework-uploads";
 	private static final String NEWS_FEED_PORTLET_CLASSNAME = "org.gcube.portlets.user.newsfeed.server.NewsServiceImpl";
-	private static String UPLOAD_LOCATION_LOCAL = System.getProperty("java.io.tmpdir");
+	private static final Logger _log = LoggerFactory.getLogger(ShareUpdateServiceImpl.class);
-
-	/**
-	 * 
-	 */
-	private static Logger _log = LoggerFactory.getLogger(ShareUpdateServiceImpl.class);
 	private DatabookStore store;
 
 	/**
@@ -146,7 +139,7 @@ public class ShareUpdateServiceImpl extends RemoteServiceServlet implements	Shar
 		String username = currUser.getUsername();
 		String email = currUser.getEmail();
 		String fullName = currUser.getFullname();
-		String thumbnailAvatarURL = currUser.getUserAvatarId();
+		String thumbnailAvatarURL = currUser.getUserAvatarURL();
 
 		// get data from the preview of the link
 		String linkTitle = preview.getTitle();
@@ -156,7 +149,7 @@ public class ShareUpdateServiceImpl extends RemoteServiceServlet implements	Shar
 		if (urlThumbnail == null)
 			urlThumbnail = "null";
 		else
-			urlThumbnail = saveThumbnailOnFTPAndGetUrl(urlThumbnail);
+			urlThumbnail = FilePreviewer.getThumbnailFromUrl(urlThumbnail, getStorage(), getServletContext());
 
 		Date feedDate = new Date();
 
@@ -192,7 +185,6 @@ public class ShareUpdateServiceImpl extends RemoteServiceServlet implements	Shar
 				}//save the feed
 				_log.trace("Success writing onto " + vreScope);				
 			}
-
 		} 
 		//share on a single VRE Timeline
 		//receives a VreId(groupId) get the scope from the groupId
@@ -228,80 +220,6 @@ public class ShareUpdateServiceImpl extends RemoteServiceServlet implements	Shar
 
 	}
 
-	/**
-	 * Check if a resource at a given url exists or not. If it exists, create a file in the temp dir
-	 * of the tomcat
-	 * @param urlThumbnail
-	 * @return
-	 */
-	private File storeAndGetFile(String urlThumbnail){
-		try {
-			HttpURLConnection.setFollowRedirects(true);
-			HttpURLConnection con =
-					(HttpURLConnection) new URL(urlThumbnail).openConnection();
-			con.setRequestMethod("HEAD"); // body is not needed yet
-			if(con.getResponseCode() == HttpURLConnection.HTTP_OK){
-
-				//generate the random dir 
-				File theRandomDir = new File(UPLOAD_LOCATION_LOCAL + File.separator + UUID.randomUUID().toString());
-				theRandomDir.mkdir();
-				theRandomDir.deleteOnExit();
-				_log.debug("Created temp upload directory in: " + theRandomDir);
-
-				// generate a random file name and create it under the randomDir
-				File file = new File(theRandomDir, UUID.randomUUID().toString().substring(0, 10)); 
-				file.deleteOnExit();
-
-				//Get the inputstream and copy there
-				URL url = new URL(urlThumbnail);
-				Streams.copy(url.openStream(), new FileOutputStream(file), true);
-				_log.debug("File is at " + file.getAbsolutePath());
-
-				return file;
-			}else
-				return null;
-		}
-		catch (Exception e) {
-			_log.error("The resource at url " + urlThumbnail + " doesn't exist");
-			return null;
-		}
-	}
-
-	/**
-	 * When a link preview needs to be saved, the method save the thumbnail on the storage no longer using the external url
-	 * @param urlThumbnail
-	 * @return the url of the thumbnail saved on the storage or null in case of error
-	 */
-	private String saveThumbnailOnFTPAndGetUrl(String urlThumbnail) {
-		File localFile;
-		if((localFile = storeAndGetFile(urlThumbnail)) != null){
-			String mimeType = null;
-			if (isWithinPortal()) {
-				try {
-					mimeType = FilePreviewer.getMimeType(localFile, localFile.getName());
-					String thumbnailUrlFTP = null;
-					switch(mimeType){
-					case "image/png":
-					case "image/gif":
-					case "image/tiff":
-					case "image/jpg":
-					case "image/jpeg":
-					case "image/bmp":
-						thumbnailUrlFTP = FilePreviewer.getImagePreview(localFile.getName(), localFile.getAbsolutePath(), null, mimeType).getImageUrls().get(0);
-						break;
-					default: break;
-					}
-					return thumbnailUrlFTP;
-				} catch (IOException e) {
-					_log.error("Error while saving thumbnail on ftp", e);
-				}
-			}
-		}else
-			_log.warn("the file at url " + urlThumbnail + " doesn't exist");
-
-		return null;
-	}
-
 	/**
 	 * Share a post with at least one attachment.
 	 */
@@ -331,7 +249,7 @@ public class ShareUpdateServiceImpl extends RemoteServiceServlet implements	Shar
 		String username = currUser.getUsername();
 		String email = currUser.getEmail();
 		String fullName = currUser.getFullname();
-		String thumbnailAvatarURL = currUser.getUserAvatarId();
+		String thumbnailAvatarURL = currUser.getUserAvatarURL();
 
 		// Managing attachments: the first one will use the same fields of a link preview.
 		// If more than one attachments are present, they will be saved as Attachment objects.
@@ -664,17 +582,14 @@ public class ShareUpdateServiceImpl extends RemoteServiceServlet implements	Shar
 	@Override
 	public LinkPreview checkUploadedFile(String fileName, String fileabsolutePathOnServer) {
 
-		PortalContext context = PortalContext.getConfiguration();
-
 		LinkPreview toReturn = null;
 
+		// a random remote folder/file on the storage for the payload
 		String randomUploadFolderName = UUID.randomUUID().toString();
 		String remoteFilePath = UPLOAD_DIR + "/" + randomUploadFolderName + "/" + fileName;
+
 		//get the Storage Client
-		String currScope = ScopeProvider.instance.get();
+		IClient storageClient = getStorage();
-		ScopeProvider.instance.set(context.getCurrentScope(getThreadLocalRequest()));
-		IClient storageClient = new StorageClient(STORAGE_OWNER, AccessType.SHARED, MemoryType.PERSISTENT).getClient();
-		ScopeProvider.instance.set(currScope);	
 
 		String httpURL = "";
 		String smpURI = "";
@@ -692,7 +607,6 @@ public class ShareUpdateServiceImpl extends RemoteServiceServlet implements	Shar
 			}
 			Thread thread = new Thread(new UploadToStorageThread(storageClient, fileName, fileabsolutePathOnServer, remoteFilePath, mimeType));
 			thread.start();
-		}
 
 			try {
 				//get the url to show (though it could not be ready for download at this stage)
@@ -700,41 +614,37 @@ public class ShareUpdateServiceImpl extends RemoteServiceServlet implements	Shar
 
 				switch (mimeType) {
 				case "application/pdf":
-				toReturn = FilePreviewer.getPdfPreview(fileName, fileabsolutePathOnServer, httpURL, mimeType);
+					toReturn = FilePreviewer.getPdfPreview(fileName, fileabsolutePathOnServer, httpURL, mimeType, storageClient, getServletContext());
 					break;
 				case "application/vnd.openxmlformats-officedocument.wordprocessingml.document":
 					mimeType = "application/wordprocessor";
-				return FilePreviewer.getUnhandledTypePreview(fileName, fileabsolutePathOnServer, httpURL, mimeType);
+					return FilePreviewer.getUnhandledTypePreview(fileName, fileabsolutePathOnServer, httpURL, mimeType, storageClient, getServletContext());
 				case "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet":
 					mimeType = "application/spreadsheet";
-				return FilePreviewer.getUnhandledTypePreview(fileName, fileabsolutePathOnServer, httpURL, mimeType);			
+					return FilePreviewer.getUnhandledTypePreview(fileName, fileabsolutePathOnServer, httpURL, mimeType, storageClient, getServletContext());			
 				case "application/vnd.openxmlformats-officedocument.presentationml.presentation":
 					mimeType = "application/presentation";
-				return FilePreviewer.getUnhandledTypePreview(fileName, fileabsolutePathOnServer, httpURL, mimeType);
+					return FilePreviewer.getUnhandledTypePreview(fileName, fileabsolutePathOnServer, httpURL, mimeType, storageClient, getServletContext());
 				case "image/png":
 				case "image/gif":
 				case "image/tiff":
 				case "image/jpg":
 				case "image/jpeg":
 				case "image/bmp":
-				toReturn = FilePreviewer.getImagePreview(fileName, fileabsolutePathOnServer, httpURL, mimeType);
+					toReturn = FilePreviewer.getImagePreview(fileName, fileabsolutePathOnServer, httpURL, mimeType, storageClient, getServletContext());
 					break;
 				default:
-				return FilePreviewer.getUnhandledTypePreview(fileName, fileabsolutePathOnServer, httpURL, mimeType);
+					return FilePreviewer.getUnhandledTypePreview(fileName, fileabsolutePathOnServer, httpURL, mimeType, storageClient, getServletContext());
-
 				}
-
 			} catch (Exception e) {
-			_log.error("Error while resolving or previewing file");
+				_log.error("Error while resolving or previewing file", e);
-			e.printStackTrace();
 				try {
-				return FilePreviewer.getUnhandledTypePreview(fileName, fileabsolutePathOnServer, httpURL, "Error During upload on Server!");
+					return FilePreviewer.getUnhandledTypePreview(fileName, fileabsolutePathOnServer, httpURL, "Error During upload on Server!", storageClient, getServletContext());
 				} catch (Exception e1) {
-				e1.printStackTrace();
+					_log.error("Unable to extract a preview ...", e1);
+				}
 			}	
-
 		}
-
 		_log.debug("smpURI=" + smpURI);
 		_log.debug("Returning httpURL=" + httpURL);
 		return toReturn;
@@ -944,4 +854,20 @@ public class ShareUpdateServiceImpl extends RemoteServiceServlet implements	Shar
 		}
 		return toReturn;
 	}
+
+	/**
+	 * Return the storage client object
+	 * @return
+	 */
+	private IClient getStorage(){
+
+		String currScope = ScopeProvider.instance.get();
+		PortalContext context = PortalContext.getConfiguration();
+		ScopeProvider.instance.set(context.getCurrentScope(getThreadLocalRequest()));
+		IClient storageClient = new StorageClient(STORAGE_OWNER, AccessType.SHARED, MemoryType.PERSISTENT).getClient();
+		ScopeProvider.instance.set(currScope);	
+		return storageClient;
+
+	}
+	
 }