Handle session expired for UIDL requests correctly (#11705)

Change-Id: I497e3b96387d16d9cb31fa9fce6daf0650af458e

server/src/com/vaadin/server/VaadinService.java

@@ -1392,7 +1392,7 @@ public abstract class VaadinService implements Serializable {
      * @throws IOException
      *             If an error occured while writing the response
      */
-    protected void writeStringResponse(VaadinResponse response,
+    public void writeStringResponse(VaadinResponse response,
             String contentType, String reponseString) throws IOException {
 
         response.setContentType(contentType);
@@ -1418,9 +1418,6 @@ public abstract class VaadinService implements Serializable {
      */
     protected void handleSessionExpired(VaadinRequest request,
             VaadinResponse response) throws ServiceException {
-        SystemMessages systemMessages = getSystemMessages(
-                ServletPortletHelper.findLocale(null, null, request), request);
-
         for (RequestHandler handler : getRequestHandlers()) {
             if (handler instanceof SessionExpiredHandler) {
                 try {
@@ -1439,6 +1436,9 @@ public abstract class VaadinService implements Serializable {
 
         try {
             // If there is a URL, try to redirect there
+            SystemMessages systemMessages = getSystemMessages(
+                    ServletPortletHelper.findLocale(null, null, request),
+                    request);
             String sessionExpiredURL = systemMessages.getSessionExpiredURL();
             if (sessionExpiredURL != null
                     && (response instanceof VaadinServletResponse)) {

server/src/com/vaadin/server/communication/UidlRequestHandler.java

@@ -30,12 +30,15 @@ import com.vaadin.server.Constants;
 import com.vaadin.server.LegacyCommunicationManager;
 import com.vaadin.server.LegacyCommunicationManager.InvalidUIDLSecurityKeyException;
 import com.vaadin.server.ServletPortletHelper;
+import com.vaadin.server.SessionExpiredHandler;
 import com.vaadin.server.SynchronizedRequestHandler;
+import com.vaadin.server.SystemMessages;
 import com.vaadin.server.VaadinRequest;
 import com.vaadin.server.VaadinResponse;
 import com.vaadin.server.VaadinService;
 import com.vaadin.server.VaadinSession;
 import com.vaadin.shared.ApplicationConstants;
+import com.vaadin.shared.JsonConstants;
 import com.vaadin.shared.Version;
 import com.vaadin.ui.Component;
 import com.vaadin.ui.UI;
@@ -50,7 +53,8 @@ import com.vaadin.ui.UI;
  * @author Vaadin Ltd
  * @since 7.1
  */
-public class UidlRequestHandler extends SynchronizedRequestHandler {
+public class UidlRequestHandler extends SynchronizedRequestHandler implements
+        SessionExpiredHandler {
 
     public static final String UIDL_PATH = "UIDL/";
 
@@ -254,4 +258,30 @@ public class UidlRequestHandler extends SynchronizedRequestHandler {
     private static final Logger getLogger() {
         return Logger.getLogger(UidlRequestHandler.class.getName());
     }
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see
+     * com.vaadin.server.SessionExpiredHandler#handleSessionExpired(com.vaadin
+     * .server.VaadinRequest, com.vaadin.server.VaadinResponse)
+     */
+    @Override
+    public boolean handleSessionExpired(VaadinRequest request,
+            VaadinResponse response) throws IOException {
+        if (!ServletPortletHelper.isUIDLRequest(request)) {
+            return false;
+        }
+        VaadinService service = request.getService();
+        SystemMessages systemMessages = service.getSystemMessages(
+                ServletPortletHelper.findLocale(null, null, request), request);
+
+        service.writeStringResponse(response, JsonConstants.JSON_CONTENT_TYPE,
+                VaadinService.createCriticalNotificationJSON(
+                        systemMessages.getSessionExpiredCaption(),
+                        systemMessages.getSessionExpiredMessage(), null,
+                        systemMessages.getSessionExpiredURL()));
+
+        return true;
+    }
 }