Feature configure delay time out (#391)

* Create a new property (hawkbit.server.ui.event.push.delay),that the
event delay forwarding is configurable.

Signed-off-by: SirWayne <dennis.melzer@bosch-si.com>

* Add javadoc

Signed-off-by: SirWayne <dennis.melzer@bosch-si.com>

* Change delay to a long

Signed-off-by: SirWayne <dennis.melzer@bosch-si.com>

hawkbit-autoconfigure/src/main/java/org/eclipse/hawkbit/autoconfigure/ui/UIAutoConfiguration.java

@@ -12,6 +12,7 @@ import java.util.concurrent.ScheduledExecutorService;
 
 import org.eclipse.hawkbit.DistributedResourceBundleMessageSource;
 import org.eclipse.hawkbit.ui.MgmtUiConfiguration;
+import org.eclipse.hawkbit.ui.UiProperties;
 import org.eclipse.hawkbit.ui.push.DelayedEventBusPushStrategy;
 import org.eclipse.hawkbit.ui.push.EventPushStrategy;
 import org.eclipse.hawkbit.ui.push.HawkbitEventProvider;
@@ -67,17 +68,24 @@ public class UIAutoConfiguration {
      * 
      * @param applicationContext
      *            the context to add the listener
-     * 
-     * @return the provider bean
+     * @param executorService
+     *            the general scheduler service
+     * @param eventBus
+     *            the ui event bus
+     * @param eventProvider
+     *            the event provider
+     * @param uiProperties
+     *            the ui properties
+     * @return the push strategy bean
      */
     @Bean
     @ConditionalOnMissingBean
     @UIScope
     public EventPushStrategy eventPushStrategy(final ConfigurableApplicationContext applicationContext,
             final ScheduledExecutorService executorService, final UIEventBus eventBus,
-            final UIEventProvider eventProvider) {
+            final UIEventProvider eventProvider, final UiProperties uiProperties) {
         final DelayedEventBusPushStrategy delayedEventBusPushStrategy = new DelayedEventBusPushStrategy(executorService,
-                eventBus, eventProvider);
+                eventBus, eventProvider, uiProperties.getEvent().getPush().getDelay());
         applicationContext.addApplicationListener(delayedEventBusPushStrategy);
         return delayedEventBusPushStrategy;
     }

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

@@ -9,6 +9,7 @@
 package org.eclipse.hawkbit.ui;
 
 import java.io.Serializable;
+import java.util.concurrent.TimeUnit;
 
 import org.springframework.boot.context.properties.ConfigurationProperties;
 
@@ -270,12 +271,49 @@ public class UiProperties implements Serializable {
         }
     }
 
+    /**
+     * Configuration of the UI event bus.
+     */
+    public static class Event implements Serializable {
+        private static final long serialVersionUID = 1L;
+
+        /**
+         * 
+         * Configuration of the UI push.
+         *
+         */
+        public static class Push implements Serializable {
+            private static final long serialVersionUID = 1L;
+
+            /**
+             * The delay for the ui event forwarding.
+             */
+            private long delay = TimeUnit.SECONDS.toMillis(2);
+
+            public long getDelay() {
+                return delay;
+            }
+
+            public void setDelay(final long delay) {
+                this.delay = delay;
+            }
+        }
+
+        private final Push push = new Push();
+
+        public Push getPush() {
+            return push;
+        }
+    }
+
     private final Links links = new Links();
 
     private final Login login = new Login();
 
     private final Demo demo = new Demo();
 
+    private final Event event = new Event();
+
     public Demo getDemo() {
         return demo;
     }
@@ -288,4 +326,8 @@ public class UiProperties implements Serializable {
         return login;
     }
 
+    public Event getEvent() {
+        return event;
+    }
+
 }

hawkbit-ui/src/main/java/org/eclipse/hawkbit/ui/push/DelayedEventBusPushStrategy.java

@@ -50,8 +50,9 @@ import com.vaadin.ui.UI;
 /**
  * An {@link EventPushStrategy} implementation which retrieves events from
  * {@link com.google.common.eventbus.EventBus} and store them first in a queue
- * where they will dispatched every 2 seconds to the {@link EventBus} in a
- * Vaadin access thread {@link UI#access(Runnable)}.
+ * where they will dispatched every x (default is 2 and can be configured with
+ * the property) seconds to the {@link EventBus} in a Vaadin access thread
+ * {@link UI#access(Runnable)}.
  *
  * This strategy avoids blocking UIs when too many events are fired and
  * dispatched to the UI thread. The UI will freeze in the time. To avoid that
@@ -71,19 +72,31 @@ public class DelayedEventBusPushStrategy implements EventPushStrategy, Applicati
             BLOCK_SIZE);
 
     private final ScheduledExecutorService executorService;
-
-    private final transient EventBus.UIEventBus eventBus;
-
+    private final EventBus.UIEventBus eventBus;
     private final UIEventProvider eventProvider;
     private ScheduledFuture<?> jobHandle;
-
+    private final long delay;
     private UI vaadinUI;
 
+    /**
+     * Constructor.
+     * 
+     * @param executorService
+     *            the general scheduler service
+     * @param eventBus
+     *            the ui event bus
+     * @param eventProvider
+     *            the event provider
+     * @param delay
+     *            the delay for the event forwarding. Every delay millisecond
+     *            the events are forwarded by this strategy
+     */
     public DelayedEventBusPushStrategy(final ScheduledExecutorService executorService, final UIEventBus eventBus,
-            final UIEventProvider eventProvider) {
+            final UIEventProvider eventProvider, final long delay) {
         this.executorService = executorService;
         this.eventBus = eventBus;
         this.eventProvider = eventProvider;
+        this.delay = delay;
     }
 
     private boolean isEventProvided(final org.eclipse.hawkbit.repository.event.TenantAwareEvent event) {
@@ -99,7 +112,7 @@ public class DelayedEventBusPushStrategy implements EventPushStrategy, Applicati
         }
 
         jobHandle = executorService.scheduleWithFixedDelay(new DispatchRunnable(vaadinUI, vaadinUI.getSession()),
-                10_000, 2_000, TimeUnit.MILLISECONDS);
+                10_000, delay, TimeUnit.MILLISECONDS);
     }
 
     @Override