Transactional annotation error

Question

When I put "@Transactional(readOnly=false)" annotation in my Service class I get the following error

Description:

The bean 'studentService' could not be injected as a 'com.student.service.StudentServiceImpl' because it is a JDK dynamic proxy that implements: com.student.service.StudentService

Sample code:

@Service("studentService")
@Transactional(readOnly=false)
public class StudentServiceImpl implements StudentService {

}

public interface StudentService {

}

Action:

Consider injecting the bean as one of its interfaces or forcing the use of CGLib-based proxies by setting proxyTargetClass=true on @EnableAsync and/or @EnableCaching.

Process finished with exit code 1

What is causing this?

Answer 1

As SO already mentioned on the comment, the error occurs when you are trying to inject/autowire the implementation class instead of interface.

The bean 'studentService' could not be injected as a 'com.student.service.StudentServiceImpl' because it is a JDK dynamic proxy that implements: com.student.service.StudentService

On the setup posted by SO,

public class StudentServiceImpl implements StudentService {
}

public interface StudentService {
}

If you autowire the interface as below you won't get an error:

@Autowired //or @Inject
StudentService studentService;

Answer 2

in spring boot projects, try to add :

spring.aop.proxy-target-class=true

to your application.properties

OR

@EnableAspectJAutoProxy(proxyTargetClass = true)

to your spring boot entry point.