Could not instantiate bean : Constructor threw exception; nested exception is java.lang.NullPointerException

Question

package baseDao;

public interface BaseDao {

    public void create(Object obj);
    public void delete(Object obj);
    public void update(Object obj);
    public void         


        

Answer 1

The problem is here:

@Autowired
private  SessionFactory usermanagementSessionFactory;
private  Session session = usermanagementSessionFactory.getCurrentSession();

The sessionFactory needs to be autowired, but this only happens after construction. Construction involves the second line being executed - which uses the unset factory. Hence you get a null pointer exception.

Even though your class doesnt have a constructor, construction of an instance can still thow an exception as a result of field initialisation, as in this case.