Java EE EJB 3.0注释

Question

I am working on Glassfish version 3 , when I am trying to compile app this error log appears in the log file,

SEVERE: The annotation symbol defined in super-class is not compatible with Session ejb ManagerDaoImpl

The annotations are @Singleton and @Stateless

Is there any way to solve this problem?

Answer 1

The bean with @Singleton annotations is for one instance by Java VM, and the bean with @Stateless is for several instances by Java VM.

If you have commons methods, you can define a base class, something like next:

public abstract class AbstractBean {
    public void commonMethod() {
        // do common operation
    }
}

public interface LocalFoo {
    public void foo();
}

public interface RemoteFoo {
    public void foo();
}

@LocalBean
@Local(LocalFoo.class)
@Remote(RemoteFoo.class)
@Stateless
public class FooBean extends AbstractBean implements LocalFoo, RemoteFoo {
    @Override
    public void foo() {
        // do something
    }
}  

Answer 2

Our bean is ;

@Stateless
@Singleton
public class ManagerDaoImpl extends AbstractDAO<X> implements ManagerDAO {

@EJB
PersonDAO personDao;
@PersistenceContext(unitName = "PoyrazPU")
private EntityManager em;

. . .

SEVERE: The annotation symbol defined in super-class is not compatible with Session ejb ManagerDaoImpl ++ SOLVED by using @LocalBean @Local(LocalFoo.class) instead of @Singleton

Our new bean is ;

@Stateless
@LocalBean
@Local(MAanagerDAO.class)
public class ManagerDaoImpl extends AbstractDAO<X> implements ManagerDAO {

@EJB
PersonDAO personDao;
@PersistenceContext(unitName = "PoyrazPU")
private EntityManager em;

The problem is solved but there is a new problem about @Lock annotation. I got this error,

SEVERE: @Lock is only permitted for singleton session beans

@Asynchronous
@Lock()
@AccessTimeout(-1)
@Override
public void doStuff(Mass mass) {

    for (int i = 0; i < RETRY_COUNT; i++) {
        notify(mass);
        try {
            Thread.sleep(TIME);
        } catch (InterruptedException ex) {
            BeanLogger.logError("Thread sleep threw exception while informing masses: ", new ThreadSleepException(ex));

        }
    }
}