Spring 3.1 Session Scope + WebRequestInterceptor Issue

[abidk]

Hi, I am porting my xml configuration to a Java config and I've come across an issue which seems to be Java Config specific.

I have a feedback message object which has a session scope:

@Component
@Scope(value = "session", proxyMode = ScopedProxyMode.INTERFACES)
public class FeedbackMessageImpl implements FeedbackMessage {
  ...
}

I'm then injecting the feedback message into a WebRequestInterceptor class, which places the message into the request.

public class FeedbackInterceptor implements WebRequestInterceptor {

  public static final String FEEDBACK_ATT = "message";

  private FeedbackMessage feedbackMessage;

  @Autowired
  public void setFeedbackMessage( FeedbackMessage feedbackMessage ) {
    this.feedbackMessage = feedbackMessage;
  }

  public void preHandle( WebRequest request ) throws Exception {
    // feedbackMessage is null, why?
    request.setAttribute( FEEDBACK_ATT, feedbackMessage.getMessages( ), RequestAttributes.SCOPE_REQUEST );
    feedbackMessage.clear();
  }
  ...
}

Controller class creates messages with no issue:

@Controller
@RequestMapping("/")
public class SomeController {
  private FeedbackMessage feedbackMessage;

  @Autowired
  public void setFeedbackMessage( FeedbackMessage feedbackMessage ) {
    this.feedbackMessage = feedbackMessage;
  }

  @RequestMapping(method = RequestMethod.POST, value = "/update")
  public ModelAndView handleDoSomething( ) {
    // feedbackMessage object exists
    feedbackMessage.addMessageCode( "some.message.keycode" );
    return new ModelAndView(  );
  }

My config look like:

@Configuration
@EnableAspectJAutoProxy
@EnableWebMvc
@PropertySource("classpath:/example.properties")
@ComponentScan(basePackages={"com.example"})
public class ApplicationContextConfig extends WebMvcConfigurerAdapter {

  @Override
  public void addInterceptors( InterceptorRegistry registry ) {
    registry.addWebRequestInterceptor( new FeedbackInterceptor( ) );
  }
  ...
}

The problem is that the feedbackMessage is null in the FeedbackInterceptor class when the 'preHandle' method is called - I can't work out why it does not work in a Java Config setup, but seems to work fine when using a XML config, anyone have any ideas?

Ps. I know there is already a message feedback in Spring 3.1, but i'm porting the existing code for now.

[Marten Deinum]

Your FeedbackInterceptor isn't a bean and as such not being injected, you are constructing it yourself inside a method. If you want it to be a bean move that to a method annotated with @Bean. So in my book works just as expected.

@Configuration
@EnableAspectJAutoProxy
@EnableWebMvc
@PropertySource("classpath:/example.properties")
@ComponentScan(basePackages={"com.example"})
public class ApplicationContextConfig extends WebMvcConfigurerAdapter {

  @Override
  public void addInterceptors( InterceptorRegistry registry ) {
    registry.addWebRequestInterceptor( feedbackInterceptor() );
  }

  @Bean
  public FeedbackInterceptor feedbackInterceptor() {
    return new FeedbackInterceptor();
  }
}

[abidk]

That worked, it seems abit obvious thinking about it now. Also, I needed to add the below, which I thought was no longer needed in Spring 3.1.

 
<listener>
    <listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>
  </listener>

Thanks

[Marten Deinum]

If the RequestContextListener is needed depends on where/how you want to use your scoped beans.