improve exception handling of ThrowingEventBus

scm-webapp/src/main/java/com/google/common/eventbus/ThrowingEventBus.java

@@ -30,10 +30,16 @@
  */
 
 
+
 package com.google.common.eventbus;
 
 //~--- non-JDK imports --------------------------------------------------------
 
+import com.google.common.base.Throwables;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import sonia.scm.event.EventBusException;
 
 //~--- JDK imports ------------------------------------------------------------
@@ -48,6 +54,14 @@ import java.lang.reflect.InvocationTargetException;
 public class ThrowingEventBus extends EventBus
 {
 
+  /**
+   * the logger for ThrowingEventBus
+   */
+  private static final Logger logger =
+    LoggerFactory.getLogger(ThrowingEventBus.class);
+
+  //~--- methods --------------------------------------------------------------
+
   /**
    * {@inheritDoc}
    *
@@ -64,8 +78,13 @@ public class ThrowingEventBus extends EventBus
     }
     catch (InvocationTargetException ex)
     {
+      Throwable cause = ex.getCause();
+
+      Throwables.propagateIfPossible(cause);
+      logger.trace("could not propagate exception, throw as EventBusException");
+
       throw new EventBusException(
-        "could not handle event ".concat(event.toString()), ex);
+        "could not handle event ".concat(event.toString()), cause);
     }
   }
 }

scm-webapp/src/test/java/sonia/scm/event/GuavaScmEventBusTest.java

@@ -30,6 +30,7 @@
  */
 
 
+
 package sonia.scm.event;
 
 //~--- non-JDK imports --------------------------------------------------------
@@ -49,6 +50,10 @@ import sonia.scm.user.UserEvent;
 
 import static org.junit.Assert.*;
 
+//~--- JDK imports ------------------------------------------------------------
+
+import java.io.IOException;
+
 /**
  *
  * @author Sebastian Sdorra
@@ -133,7 +138,30 @@ public class GuavaScmEventBusTest extends AbstractTestBase
    *
    */
   @Test(expected = EventBusException.class)
-  public void testSyncPostWithException()
+  public void testSyncPostWithCheckedException()
+  {
+    GuavaScmEventBus eventBus = new GuavaScmEventBus();
+
+    eventBus.register(new Object()
+    {
+
+      @Subscribe
+      public void handleEvent(Object event) throws IOException
+      {
+        throw new IOException("could not handle event");
+      }
+
+    }, false);
+
+    eventBus.post(new Object());
+  }
+
+  /**
+   * Method description
+   *
+   */
+  @Test(expected = RuntimeException.class)
+  public void testSyncPostWithRuntimeException()
   {
     GuavaScmEventBus eventBus = new GuavaScmEventBus();