diff --git a/src/main/java/org/gcube/portlets/widgets/workspaceuploader/client/WorkspaceUploaderListenerController.java b/src/main/java/org/gcube/portlets/widgets/workspaceuploader/client/WorkspaceUploaderListenerController.java
index d764d0c..9b602c1 100644
--- a/src/main/java/org/gcube/portlets/widgets/workspaceuploader/client/WorkspaceUploaderListenerController.java
+++ b/src/main/java/org/gcube/portlets/widgets/workspaceuploader/client/WorkspaceUploaderListenerController.java
@@ -12,6 +12,7 @@ import org.gcube.portlets.widgets.workspaceuploader.client.events.NotifyUploadEv
 
 import com.google.gwt.core.shared.GWT;
 import com.google.gwt.event.shared.HandlerManager;
+import com.google.gwt.user.client.Timer;
 
 
 /**
@@ -42,7 +43,7 @@ public class WorkspaceUploaderListenerController {
 		controllerEventBus.addHandler(NotifyUploadEvent.TYPE, new NotifyUploadEventHandler() {
 
 			@Override
-			public void onNotifyUpload(NotifyUploadEvent notifyUploadEvent) {
+			public void onNotifyUpload(final NotifyUploadEvent notifyUploadEvent) {
 
 				if(notifyUploadEvent.getEvent()==null)
 					return;
@@ -51,7 +52,17 @@ public class WorkspaceUploaderListenerController {
 
 				case UPLOAD_COMPLETED:
 					GWT.log("NotifyUploadEvent Completed");
-					notifyUploadCompleted(notifyUploadEvent.getParentId(), notifyUploadEvent.getItemId());
+
+					Timer timer = new Timer() {
+
+						@Override
+						public void run() {
+
+							notifyUploadCompleted(notifyUploadEvent.getParentId(), notifyUploadEvent.getItemId());
+						}
+					};
+					//THIS IS A DELAY TO WAIT REPOSITORY SYNCHRONIZATION
+					timer.schedule(2000);
 					break;
 				case ABORTED:
 					GWT.log("NotifyUploadEvent Aborted");
diff --git a/src/main/java/org/gcube/portlets/widgets/workspaceuploader/server/WorkspaceUploadServletStream.java b/src/main/java/org/gcube/portlets/widgets/workspaceuploader/server/WorkspaceUploadServletStream.java
index 338a9de..d34c39b 100644
--- a/src/main/java/org/gcube/portlets/widgets/workspaceuploader/server/WorkspaceUploadServletStream.java
+++ b/src/main/java/org/gcube/portlets/widgets/workspaceuploader/server/WorkspaceUploadServletStream.java
@@ -3,11 +3,15 @@
  */
 package org.gcube.portlets.widgets.workspaceuploader.server;
 
+import java.io.File;
+import java.io.FileOutputStream;
 import java.io.IOException;
+import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Random;
+import java.util.UUID;
 import java.util.concurrent.TimeUnit;
 
 import javax.servlet.Servlet;
@@ -26,6 +30,7 @@ import org.apache.commons.fileupload.disk.DiskFileItemFactory;
 import org.apache.commons.fileupload.servlet.ServletFileUpload;
 import org.apache.commons.fileupload.util.Streams;
 import org.apache.commons.io.FilenameUtils;
+import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang.Validate;
 import org.gcube.common.portal.PortalContext;
 import org.gcube.common.storagehub.model.items.FolderItem;
@@ -38,6 +43,7 @@ import org.gcube.common.storagehubwrapper.shared.tohl.exceptions.InsufficientPri
 import org.gcube.common.storagehubwrapper.shared.tohl.exceptions.InternalErrorException;
 import org.gcube.common.storagehubwrapper.shared.tohl.exceptions.ItemAlreadyExistException;
 import org.gcube.common.storagehubwrapper.shared.tohl.exceptions.ItemNotFoundException;
+import org.gcube.common.storagehubwrapper.shared.tohl.exceptions.WrongItemTypeException;
 import org.gcube.portlets.widgets.workspaceuploader.client.ConstantsWorkspaceUploader;
 import org.gcube.portlets.widgets.workspaceuploader.server.notification.NotificationsWorkspaceUploader;
 import org.gcube.portlets.widgets.workspaceuploader.server.notification.NotificationsWorkspaceUploaderProducer;
@@ -273,6 +279,33 @@ public class WorkspaceUploadServletStream extends HttpServlet implements Servlet
 		}
 	}
 
+	public File coyStreamToFile(InputStream in, String fileExtension) throws IOException{
+		File tempFile = File.createTempFile(UUID.randomUUID().toString(), fileExtension);
+		tempFile.deleteOnExit();
+		FileOutputStream out = new FileOutputStream(tempFile);
+		IOUtils.copy(in, out);
+		return tempFile;
+	}
+
+//	public static InputStream clone(final InputStream inputStream) {
+//        try {
+//            inputStream.mark(0);
+//            ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+//            byte[] buffer = new byte[1024];
+//            int readLength = 0;
+//            while ((readLength = inputStream.read(buffer)) != -1) {
+//                outputStream.write(buffer, 0, readLength);
+//            }
+//            inputStream.reset();
+//            outputStream.flush();
+//            return new ByteArrayInputStream(outputStream.toByteArray());
+//        }
+//        catch (Exception ex) {
+//            ex.printStackTrace();
+//        }
+//        return null;
+//    }
+
 
 
 	/**
@@ -434,6 +467,9 @@ public class WorkspaceUploadServletStream extends HttpServlet implements Servlet
 		}
 
 		final WorkspaceFolder destinationFolder = (WorkspaceFolder) item;
+//		File tmpFile = null;
+//		FileInputStream fis = null;
+//		BufferedInputStream bis = null;
 		try {
 			//we calculate an unique name for the current destination
 			String itemName = fileName;
@@ -477,6 +513,10 @@ public class WorkspaceUploadServletStream extends HttpServlet implements Servlet
 			//CONFIRM DESTINATION FOLDER
 			workspaceUploader.getFile().setParentId(destinationFolder.getId());
 
+//			tmpFile = coyStreamToFile(uploadItem.openStream(), extension);
+//			fis = new FileInputStream(tmpFile);
+//			bis = new BufferedInputStream(fis);
+
 			//instanciate the progress listener
 			final AbstractUploadProgressListener uploadProgressListener = createNewListener(request.getSession(), clientUploadKey);
 			final UploadProgressInputStream inputStream = new UploadProgressInputStream(uploadItem.openStream(), size);
@@ -489,6 +529,14 @@ public class WorkspaceUploadServletStream extends HttpServlet implements Servlet
 
 			if(uploadType.compareTo(FILE)==0) {//IS FILE UPLOAD
 
+				try {
+					//USING isOverwrite to check if the file already exists
+					isOverwrite = storageHubWrapper.getWorkspace().exists(itemName, destinationFolder.getId());
+				}
+				catch (ItemNotFoundException | WrongItemTypeException e) {
+					//silent
+				}
+
 				workspaceUploader = WorkspaceUploaderMng.uploadFile(storageHubWrapper, user, scopeGroupId, request, workspaceUploader, request.getSession(), itemName, inputStream, destinationFolder, contentType, isOverwrite, size);
 
 				if(workspaceUploader==null)
@@ -552,6 +600,18 @@ public class WorkspaceUploadServletStream extends HttpServlet implements Servlet
 //			return;
 		}finally{
 			removeCurrentListener(request.getSession(), clientUploadKey);
+
+//			try{
+//				if(fis!=null)
+//					fis.close();
+//				if (bis!=null)
+//					bis.close();
+//				if(tmpFile!=null && tmpFile.exists())
+//					tmpFile.delete();
+//			}catch(Exception e){
+//				e.printStackTrace();
+//			}
+
 		}
 	}