Fix localization vaadin system messages (#807)

* Add customized SystemMessagesProvider
* Localize according to SystemMessagesInfo
* Localize vaadin 'Server connection lost' message
* Use available locale for system messages
* Add license header
* Fix PR findings
* Fix Sonar issues

Signed-off-by: Stefan Klotz <stefan.klotz@bosch-si.com>

hawkbit-runtime/hawkbit-update-server/src/main/java/org/eclipse/hawkbit/app/MyUI.java

@@ -14,6 +14,7 @@ import org.eclipse.hawkbit.ui.UiProperties;
 import org.eclipse.hawkbit.ui.components.NotificationUnreadButton;
 import org.eclipse.hawkbit.ui.menu.DashboardMenu;
 import org.eclipse.hawkbit.ui.push.EventPushStrategy;
+import org.eclipse.hawkbit.ui.utils.VaadinMessageSource;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.ApplicationContext;
 import org.vaadin.spring.events.EventBus.UIEventBus;
@@ -44,9 +45,10 @@ public class MyUI extends AbstractHawkbitUI {
     @Autowired
     MyUI(final EventPushStrategy pushStrategy, final UIEventBus eventBus, final SpringViewProvider viewProvider,
             final ApplicationContext context, final DashboardMenu dashboardMenu, final ErrorView errorview,
-            final NotificationUnreadButton notificationUnreadButton, final UiProperties uiProperties) {
+            final NotificationUnreadButton notificationUnreadButton, final UiProperties uiProperties,
+            final VaadinMessageSource i18n) {
         super(pushStrategy, eventBus, viewProvider, context, dashboardMenu, errorview, notificationUnreadButton,
-                uiProperties);
+                uiProperties, i18n);
     }
 
 }

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/AbstractHawkbitUI.java

@@ -17,6 +17,7 @@ import org.eclipse.hawkbit.ui.push.EventPushStrategy;
 import org.eclipse.hawkbit.ui.themes.HawkbitTheme;
 import org.eclipse.hawkbit.ui.utils.HawkbitCommonUtil;
 import org.eclipse.hawkbit.ui.utils.SpringContextHelper;
+import org.eclipse.hawkbit.ui.utils.VaadinMessageSource;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.context.ApplicationContext;
@@ -76,10 +77,12 @@ public abstract class AbstractHawkbitUI extends UI implements DetachListener {
 
     private final UiProperties uiProperties;
 
+    private final VaadinMessageSource i18n;
+
     protected AbstractHawkbitUI(final EventPushStrategy pushStrategy, final UIEventBus eventBus,
             final SpringViewProvider viewProvider, final ApplicationContext context, final DashboardMenu dashboardMenu,
             final ErrorView errorview, final NotificationUnreadButton notificationUnreadButton,
-            final UiProperties uiProperties) {
+            final UiProperties uiProperties, final VaadinMessageSource i18n) {
         this.pushStrategy = pushStrategy;
         this.eventBus = eventBus;
         this.viewProvider = viewProvider;
@@ -88,6 +91,7 @@ public abstract class AbstractHawkbitUI extends UI implements DetachListener {
         this.errorview = errorview;
         this.notificationUnreadButton = notificationUnreadButton;
         this.uiProperties = uiProperties;
+        this.i18n = i18n;
     }
 
     @Override
@@ -115,7 +119,7 @@ public abstract class AbstractHawkbitUI extends UI implements DetachListener {
         final HorizontalLayout rootLayout = new HorizontalLayout();
         rootLayout.setSizeFull();
 
-        setLocale(HawkbitCommonUtil.getLocaleToBeUsed(uiProperties.getLocalization(), getUI()));
+        HawkbitCommonUtil.initLocalization(this, uiProperties.getLocalization(), i18n);
 
         dashboardMenu.init();
         dashboardMenu.setResponsive(true);

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/AsyncVaadinServletConfiguration.java

@@ -8,16 +8,21 @@
  */
 package org.eclipse.hawkbit.ui;
 
+import javax.servlet.ServletException;
+
 import org.atmosphere.container.JSR356AsyncSupport;
 import org.atmosphere.cpr.ApplicationConfig;
+import org.eclipse.hawkbit.ui.utils.VaadinMessageSource;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.boot.web.servlet.ServletRegistrationBean;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Import;
 
+import com.vaadin.server.VaadinServlet;
 import com.vaadin.spring.boot.internal.VaadinServletConfiguration;
 import com.vaadin.spring.boot.internal.VaadinServletConfigurationProperties;
+import com.vaadin.spring.server.SpringVaadinServlet;
 
 /**
  * {@link VaadinServletConfiguration} that sets the context path for
@@ -29,6 +34,23 @@ import com.vaadin.spring.boot.internal.VaadinServletConfigurationProperties;
 @Import(VaadinServletConfiguration.class)
 public class AsyncVaadinServletConfiguration extends VaadinServletConfiguration {
 
+    @Bean
+    public LocalizedSystemMessagesProvider localizedSystemMessagesProvider(final UiProperties uiProperties,
+            final VaadinMessageSource i18n) {
+        return new LocalizedSystemMessagesProvider(uiProperties, i18n);
+    }
+
+    @Bean
+    public VaadinServlet vaadinServlet(final LocalizedSystemMessagesProvider localizedSystemMessagesProvider) {
+        return new SpringVaadinServlet() {
+            @Override
+            public void servletInitialized() throws ServletException {
+                super.servletInitialized();
+                getService().setSystemMessagesProvider(localizedSystemMessagesProvider);
+            }
+        };
+    }
+
     @Override
     @Bean
     protected ServletRegistrationBean vaadinServletRegistration() {

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/LocalizedSystemMessagesProvider.java

@@ -0,0 +1,68 @@
+/**
+ * Copyright (c) 2019 Bosch Software Innovations GmbH and others.
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.eclipse.hawkbit.ui;
+
+import java.util.Locale;
+
+import org.eclipse.hawkbit.ui.utils.HawkbitCommonUtil;
+import org.eclipse.hawkbit.ui.utils.UIMessageIdProvider;
+import org.eclipse.hawkbit.ui.utils.VaadinMessageSource;
+
+import com.vaadin.server.CustomizedSystemMessages;
+import com.vaadin.server.SystemMessages;
+import com.vaadin.server.SystemMessagesInfo;
+import com.vaadin.server.SystemMessagesProvider;
+
+/**
+ * {@link SystemMessagesProvider} that localizes Vaadin system messages.
+ *
+ */
+public class LocalizedSystemMessagesProvider implements SystemMessagesProvider {
+    private static final long serialVersionUID = 1L;
+
+    private final VaadinMessageSource i18n;
+    private final UiProperties uiProperties;
+
+    /**
+     * @param uiProperties
+     *            Properties to determine the available Locales
+     * @param i18n
+     *            Message source used for localization
+     */
+    public LocalizedSystemMessagesProvider(final UiProperties uiProperties, final VaadinMessageSource i18n) {
+        this.i18n = i18n;
+        this.uiProperties = uiProperties;
+    }
+
+    private SystemMessages getLocalizedSystemMessages(final VaadinMessageSource i18n, final Locale local) {
+        final CustomizedSystemMessages messages = new CustomizedSystemMessages();
+        final Locale desiredLocale = HawkbitCommonUtil.getLocaleToBeUsed(uiProperties.getLocalization(), local);
+
+        messages.setSessionExpiredCaption(
+                i18n.getMessage(desiredLocale, UIMessageIdProvider.VAADIN_SYSTEM_SESSIONEXPIRED_CAPTION));
+        messages.setSessionExpiredMessage(
+                i18n.getMessage(desiredLocale, UIMessageIdProvider.VAADIN_SYSTEM_SESSIONEXPIRED_MESSAGE));
+        messages.setCommunicationErrorCaption(
+                i18n.getMessage(desiredLocale, UIMessageIdProvider.VAADIN_SYSTEM_COMMUNICATIONERROR_CAPTION));
+        messages.setCommunicationErrorMessage(
+                i18n.getMessage(desiredLocale, UIMessageIdProvider.VAADIN_SYSTEM_COMMUNICATIONERROR_MESSAGE));
+        messages.setInternalErrorCaption(
+                i18n.getMessage(desiredLocale, UIMessageIdProvider.VAADIN_SYSTEM_INTERNALERROR_CAPTION));
+        messages.setInternalErrorMessage(
+                i18n.getMessage(desiredLocale, UIMessageIdProvider.VAADIN_SYSTEM_INTERNALERROR_MESSAGE));
+
+        return messages;
+    }
+
+    @Override
+    public SystemMessages getSystemMessages(final SystemMessagesInfo systemMessagesInfo) {
+        return getLocalizedSystemMessages(i18n, systemMessagesInfo.getLocale());
+    }
+
+}

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/login/AbstractHawkbitLoginUI.java

@@ -120,7 +120,7 @@ public abstract class AbstractHawkbitLoginUI extends UI {
 
     @Override
     protected void init(final VaadinRequest request) {
-        setLocale(HawkbitCommonUtil.getLocaleToBeUsed(uiProperties.getLocalization(), getUI()));
+        HawkbitCommonUtil.initLocalization(this, uiProperties.getLocalization(), i18n);
         SpringContextHelper.setContext(context);
 
         params = UriComponentsBuilder.fromUri(Page.getCurrent().getLocation()).build().getQueryParams();

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/utils/HawkbitCommonUtil.java

@@ -20,6 +20,7 @@ import org.eclipse.hawkbit.repository.model.PollStatus;
 import org.eclipse.hawkbit.repository.model.RolloutGroup;
 import org.eclipse.hawkbit.repository.model.TargetUpdateStatus;
 import org.eclipse.hawkbit.ui.UiProperties;
+import org.eclipse.hawkbit.ui.UiProperties.Localization;
 import org.eclipse.hawkbit.ui.rollout.StatusFontIcon;
 import org.springframework.util.StringUtils;
 import org.vaadin.addons.lazyquerycontainer.AbstractBeanQuery;
@@ -563,24 +564,41 @@ public final class HawkbitCommonUtil {
 
     /**
      * Determine the language that should be used considering localization
-     * properties and UI settings
+     * properties and a desired Locale
      * 
      * @param localizationProperties
      *            UI Localization settings
-     * @param ui
+     * @param desiredLocale
-     *            UI which settings are considered
+     *            desired Locale
      * @return Locale to be used according to UI and properties
      */
-    public static Locale getLocaleToBeUsed(final UiProperties.Localization localizationProperties, final UI ui) {
+    public static Locale getLocaleToBeUsed(final UiProperties.Localization localizationProperties,
+            final Locale desiredLocale) {
         final List<String> availableLocals = localizationProperties.getAvailableLocals();
-        final Locale uiLocale = ui.getSession().getLocale();
         // ckeck if language code of UI locale matches an available local.
         // Country, region and variant are ignored. "availableLocals" must only
         // contain language codes without country or other extensions.
-        if (availableLocals.contains(uiLocale.getLanguage())) {
+        if (availableLocals.contains(desiredLocale.getLanguage())) {
-            return uiLocale;
+            return desiredLocale;
         }
         return new Locale(localizationProperties.getDefaultLocal());
     }
 
+    /**
+     * Set localization considering properties and UI settings.
+     * 
+     * @param ui
+     *            UI to setup
+     * @param localizationProperties
+     *            UI localization settings
+     * @param i18n
+     *            Localization message source
+     */
+    public static void initLocalization(final UI ui, final Localization localizationProperties,
+            final VaadinMessageSource i18n) {
+        ui.setLocale(HawkbitCommonUtil.getLocaleToBeUsed(localizationProperties, ui.getSession().getLocale()));
+        ui.getReconnectDialogConfiguration()
+                .setDialogText(i18n.getMessage(UIMessageIdProvider.VAADIN_SYSTEM_TRYINGRECONNECT));
+    }
+
 }

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/utils/UIMessageIdProvider.java

@@ -183,6 +183,20 @@ public final class UIMessageIdProvider {
 
     public static final String MESSAGE_TARGET_BULKUPLOAD_RESULT_FAIL = "message.bulk.upload.result.fail";
 
+    public static final String VAADIN_SYSTEM_SESSIONEXPIRED_CAPTION = "vaadin.system.sessionexpired.caption";
+
+    public static final String VAADIN_SYSTEM_SESSIONEXPIRED_MESSAGE = "vaadin.system.sessionexpired.message";
+
+    public static final String VAADIN_SYSTEM_COMMUNICATIONERROR_CAPTION = "vaadin.system.communicationerror.caption";
+
+    public static final String VAADIN_SYSTEM_COMMUNICATIONERROR_MESSAGE = "vaadin.system.communicationerror.message";
+
+    public static final String VAADIN_SYSTEM_INTERNALERROR_CAPTION = "vaadin.system.internalerror.caption";
+
+    public static final String VAADIN_SYSTEM_INTERNALERROR_MESSAGE = "vaadin.system.internalerror.message";
+
+    public static final String VAADIN_SYSTEM_TRYINGRECONNECT = "vaadin.system.tryingreconnect";
+
     public static final String TOOLTIP_ROLLOUT_STATUS_PREFIX = "tooltip.rollout.status.";
 
     /**

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/utils/VaadinMessageSource.java

@@ -55,8 +55,26 @@ public class VaadinMessageSource implements Serializable {
      * @see HawkbitCommonUtil#getCurrentLocale()
      */
     public String getMessage(final String code, final Object... args) {
+        return getMessage(HawkbitCommonUtil.getCurrentLocale(), code, args);
+    }
+
+    /**
+     * Tries to resolve the message based on the provided Local. Returns message
+     * code if fitting message could not be found.
+     * 
+     * @param local
+     *            to determinate the Language.
+     * @param code
+     *            the code to lookup up.
+     * @param args
+     *            Array of arguments that will be filled in for params within
+     *            the message.
+     * 
+     * @return the resolved message, or the message code if the lookup fails.
+     */
+    public String getMessage(final Locale local, final String code, final Object... args) {
         try {
-            return source.getMessage(code, args, HawkbitCommonUtil.getCurrentLocale());
+            return source.getMessage(code, args, local);
         } catch (final NoSuchMessageException ex) {
             LOG.error("Failed to retrieve message!", ex);
             return code;

hawkbit-ui/src/main/resources/messages.properties

@@ -707,3 +707,12 @@ character.whitespace = whitespace
 character.digits = digits
 character.quotationMarks = quotation marks
 character.slashes = slashes
+
+# Vaadin system messages
+vaadin.system.sessionexpired.caption=Session Expired
+vaadin.system.sessionexpired.message=Take note of any unsaved data, and click here or press ESC key to continue.
+vaadin.system.communicationerror.caption=Communication problem
+vaadin.system.communicationerror.message=Take note of any unsaved data, and click here or press ESC to continue.
+vaadin.system.internalerror.caption=Internal error
+vaadin.system.internalerror.message=Please notify the administrator. Take note of any unsaved data, and click here or press ESC to continue.
+vaadin.system.tryingreconnect=Server connection lost, trying to reconnect...