DATAMONGO-333 - Default to Object for AbstractMongoEventlistener domain type.

In case an extension of AbstractMongoEventListener does not define a parameter type we now default to Object as handled domain type as we'd cause a NullPointerException if not.

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/mapping/event/AbstractMongoEventListener.java

@@ -36,7 +36,8 @@ public abstract class AbstractMongoEventListener<E> implements ApplicationListen
 	 * Creates a new {@link AbstractMongoEventListener}.
 	 */
 	public AbstractMongoEventListener() {
-		this.domainClass = GenericTypeResolver.resolveTypeArgument(this.getClass(), AbstractMongoEventListener.class);
+		Class<?> typeArgument = GenericTypeResolver.resolveTypeArgument(this.getClass(), AbstractMongoEventListener.class);
+		this.domainClass = typeArgument == null ? Object.class : typeArgument;
 	}
 
 	/*

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/mapping/event/AbstractMongoEventListenerUnitTest.java

@@ -115,6 +115,17 @@ public class AbstractMongoEventListenerUnitTest {
 		assertThat(personListener.invokedOnAfterLoad, is(false));
 		assertThat(contactListener.invokedOnAfterLoad, is(true));
 	}
+	
+	/**
+	 * @see DATADOC-333
+	 */
+	@Test
+	@SuppressWarnings({ "rawtypes", "unchecked" })
+	public void handlesUntypedImplementations() {
+		
+		UntypedEventListener listener = new UntypedEventListener();
+		listener.onApplicationEvent(new MongoMappingEvent(new Object(), new BasicDBObject()));
+	}
 
 	class SamplePersonEventListener extends AbstractMongoEventListener<Person> {
 
@@ -163,4 +174,9 @@ public class AbstractMongoEventListenerUnitTest {
 			invokedOnAfterLoad = true;
 		}
 	}
+
+	@SuppressWarnings("rawtypes")
+	class UntypedEventListener extends AbstractMongoEventListener {
+		
+	}
 }