Question

I’m developing web application supported by Spring Integration. I’m using 1.0.4.RELEASE. I use CGLib proxies. I have a transactional message endpoint. Everything worked correctly, but I experimented a little bit with annotations. I use annotation-config, which works fine. I started from switching my service-activator configuration from xml to annotations, but it failed.

The following configuration worked correctly:

spring-integration.xml

<channel id="inChannel" />
<channel id="outChannel" />
<service-activator method="myMethod" input-channel="inChannel" ref="myService" output-channel="outChannel" />

MyService.java

@MessageEndpoint
@Transactional
public class MyService {

   @Autowired
   private MyDao myDao;

   public MyObject myMethod(String message) throws Exception {
      ...
   }

}

Trying to achieve exactly the same functionality using annotations (having in mind that I use CGLIB, so I do not need interface, but default constructor) I

• removed service-activator from my .xml
• changed MyService:

Changed MyService.java

@MessageEndpoint
@Transactional
public class MyService {

   @Autowired
   private MyDao myDao;

   public MyService () {
   }

   @ServiceActivator(inputChannel="inChannel", outputChannel="outChannel")
   public MyObject myMethod(String message) throws Exception {
      ...
   }

}

I get the following error:
java.lang.IllegalArgumentException: Superclass has no null constructors but no arguments were given

I’ve seen many threads describing the following error article, but the problem was about custom classes. My problem regards Spring class.

Error creating bean with name 'myService'
nested exception is org.springframework.aop.framework.AopConfigException
Could not generate CGLIB subclass of class [class org.springframework.integration.handler.ServiceActivatingHandler]
java.lang.IllegalArgumentException: Superclass has no null constructors but no arguments were given

What’s wrong? Why Spring tries to create proxy for spring class but not only for MyService? Is my class somehow wrapped? I don’t understand what’s happening. Help greatly appreciated.

Answer 1

Try taking off the @Autowired Tag. That looks for a constructor or setter method in order to populate that field. Considering you have neither of those, that might be the problem. Just a guess though.