Catch and log exceptions in session lifecycle listeners (#12915)

Change-Id: Ie8638f010d74c569c5ff56e91c95e23a5cb92c9b

2 files changed, 51 insertions, 3 deletions

diff --git a/server/src/com/vaadin/event/EventRouter.java b/server/src/com/vaadin/event/EventRouter.java
index 73bfa33881..fdc543143b 100644
--- a/server/src/com/vaadin/event/EventRouter.java
+++ b/server/src/com/vaadin/event/EventRouter.java
@@ -23,6 +23,10 @@ import java.util.EventObject;
 import java.util.Iterator;
 import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.logging.Logger;
+
+import com.vaadin.server.ErrorEvent;
+import com.vaadin.server.ErrorHandler;
 
 /**
  * <code>EventRouter</code> class implementing the inheritable event listening
@@ -154,6 +158,25 @@ public class EventRouter implements MethodEventSource {
      *            the Event to be sent to all listeners.
      */
     public void fireEvent(EventObject event) {
+        fireEvent(event, null);
+    }
+
+    /**
+     * Sends an event to all registered listeners. The listeners will decide if
+     * the activation method should be called or not.
+     * <p>
+     * If an error handler is set, the processing of other listeners will
+     * continue after the error handler method call unless the error handler
+     * itself throws an exception.
+     * 
+     * @param event
+     *            the Event to be sent to all listeners.
+     * @param errorHandler
+     *            error handler to use to handle any exceptions thrown by
+     *            listeners or null to let the exception propagate to the
+     *            caller, preventing further listener calls
+     */
+    public void fireEvent(EventObject event, ErrorHandler errorHandler) {
         // It is not necessary to send any events if there are no listeners
         if (listenerList != null) {
 
@@ -164,7 +187,16 @@ public class EventRouter implements MethodEventSource {
             // will filter out unwanted events.
             final Object[] listeners = listenerList.toArray();
             for (int i = 0; i < listeners.length; i++) {
-                ((ListenerMethod) listeners[i]).receiveEvent(event);
+                ListenerMethod listenerMethod = (ListenerMethod) listeners[i];
+                if (null != errorHandler) {
+                    try {
+                        listenerMethod.receiveEvent(event);
+                    } catch (Exception e) {
+                        errorHandler.error(new ErrorEvent(e));
+                    }
+                } else {
+                    listenerMethod.receiveEvent(event);
+                }
             }
 
         }
@@ -208,4 +240,9 @@ public class EventRouter implements MethodEventSource {
         }
         return listeners;
     }
+
+    private Logger getLogger() {
+        return Logger.getLogger(EventRouter.class.getName());
+    }
+
 }
diff --git a/server/src/com/vaadin/server/VaadinService.java b/server/src/com/vaadin/server/VaadinService.java
index 44ceaaaf87..216adce3c8 100644
--- a/server/src/com/vaadin/server/VaadinService.java
+++ b/server/src/com/vaadin/server/VaadinService.java
@@ -414,6 +414,9 @@ public abstract class VaadinService implements Serializable {
     /**
      * Adds a listener that gets notified when a Vaadin service session that has
      * been initialized for this service is destroyed.
+     * <p>
+     * The session being destroyed is locked and its UIs have been removed when
+     * the listeners are called.
      * 
      * @see #addSessionInitListener(SessionInitListener)
      * 
@@ -455,8 +458,11 @@ public abstract class VaadinService implements Serializable {
                         }
                     });
                 }
+                // for now, use the session error handler; in the future, could
+                // have an API for using some other handler for session init and
+                // destroy listeners
                 eventRouter.fireEvent(new SessionDestroyEvent(
-                        VaadinService.this, session));
+                        VaadinService.this, session), session.getErrorHandler());
             }
         });
     }
@@ -770,7 +776,12 @@ public abstract class VaadinService implements Serializable {
 
     private void onVaadinSessionStarted(VaadinRequest request,
             VaadinSession session) throws ServiceException {
-        eventRouter.fireEvent(new SessionInitEvent(this, session, request));
+        // for now, use the session error handler; in the future, could have an
+        // API for using some other handler for session init and destroy
+        // listeners
+
+        eventRouter.fireEvent(new SessionInitEvent(this, session, request),
+                session.getErrorHandler());
 
         ServletPortletHelper.checkUiProviders(session, this);
     }