Autowiring is not working if test listener used in JUnit & Spring

Question

I found, that uncommenting test listener annotation causes test not working below (autowired member is not initialized and NullPointerException occurs):

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = TestExecutionListenerTry2._Config.class)
//@TestExecutionListeners({TestExecutionListenerTry2._Listener.class})
public class TestExecutionListenerTry2 {

   public static class Bean1 {
      {
         System.out.println("Bean1 constructor");
      }

      public void method() {
         System.out.println("method()");
      }
   }

   @Configuration
   public static class _Config {

      @Bean
      public Bean1 bean1() {
         return new Bean1();
      }

   }

   public static class _Listener extends AbstractTestExecutionListener {
      @Override
      public void prepareTestInstance(TestContext testContext) throws Exception {
         System.out.println("prepareTestInstance");
      }

      @Override
      public void beforeTestClass(TestContext testContext) throws Exception {
         System.out.println("beforeTestClass");
      }
   }

   @Autowired
   public Bean1 bean1;

   @Test
   public void testMethod() {
      bean1.method();
   }
}

Why?

score 4 · Accepted Answer · answered Oct 06 '15 at 21:11

When you provide a @TestExecutionListeners annotation, you overwrite the default list of TestExecutionListener types, which includes a DependencyInjectionTestExecutionListener that handles dependency injection.

The default types are declared in the TestExecutionListener javadoc:

Spring provides the following out-of-the-box implementations (all of which implement Ordered):

ServletTestExecutionListener

DependencyInjectionTestExecutionListener

DirtiesContextTestExecutionListener

TransactionalTestExecutionListener

SqlScriptsTestExecutionListener

Either register those as well. Or merge yours and the defaults with the technique outlined in the Spring documentation

To avoid having to be aware of and re-declare all default listeners, the mergeMode attribute of @TestExecutionListeners can be set to MergeMode.MERGE_WITH_DEFAULTS. MERGE_WITH_DEFAULTS indicates that locally declared listeners should be merged with the default listeners.

So your annotation would look like

@TestExecutionListeners(value = { TestExecutionListenerTry2._Listener.class },
        mergeMode = MergeMode.MERGE_WITH_DEFAULTS)

I'm getting the null exception on a member in my TestExecutionListener even when using the MergeMode.MERGE_WITH_DEFAULTS, like this question: http://stackoverflow.com/questions/42204840/spring-dependency-injection-into-spring-testexecutionlisteners-not-working What's the difference? — k-den, Mar 31 '17 at 15:41

Autowiring is not working if test listener used in JUnit & Spring

1 Answers1