DATAREST-353 - Fixed potential NullPointerException when trying to delete a non-existing resource.

We now correctly return a 404 Not Found in case we receive a DELETE request for a resource not existing.

spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/RepositoryEntityController.java

@@ -326,6 +326,10 @@ class RepositoryEntityController extends AbstractRepositoryRestController implem
 		RepositoryInvoker invoker = resourceInformation.getInvoker();
 		Object domainObj = invoker.invokeFindOne(id);
 
+		if (domainObj == null) {
+			throw new ResourceNotFoundException();
+		}
+
 		publisher.publishEvent(new BeforeDeleteEvent(domainObj));
 		invoker.invokeDelete(id);
 		publisher.publishEvent(new AfterDeleteEvent(domainObj));

spring-data-rest-webmvc/src/test/java/org/springframework/data/rest/webmvc/jpa/JpaWebTests.java

@@ -524,6 +524,18 @@ public class JpaWebTests extends AbstractWebIntegrationTests {
 		assertThat(JsonPath.<JSONArray> read(responseBody, "$.content"), hasSize(0));
 	}
 
+	/**
+	 * @see DATAREST-353
+	 */
+	@Test
+	public void returns404WhenTryingToDeleteANonExistingResource() throws Exception {
+
+		Link authorsLink = discoverUnique("authors");
+
+		mvc.perform(delete(authorsLink.getHref().concat("/{id}"), 4711)).//
+				andExpect(status().isNotFound());
+	}
+
 	/**
 	 * Asserts the {@link Person} resource the given link points to contains siblings with the given names.
 	 *