Generic DAO cause stack overflow

Question

Hello I Have a problem with my Spring/Hibernate project. I was trying to implement generic classes for DAOs and Services and use one concrete implementation to show something on screen. Everything starts without error, but if i wanna create a new project, after form submisions it throws Stack Overflow error (see image below). I rly cant find out where the problem is. I hope someone here can help me. Below you can see all my code, potentialy can add jsp or config files if necessary. Thanks for your time.

GenericDaoImpl

@SuppressWarnings("unchecked")
@Repository
public abstract class GenericDaoImpl<T, PK extends Serializable> implements IGenericDao<T, PK> {

    @Autowired
    private SessionFactory sessionFactory;

    protected Class<? extends T> entityClass;

     public GenericDaoImpl() {
        Type t = getClass().getGenericSuperclass();
        ParameterizedType pt = (ParameterizedType) t;
        entityClass = (Class<? extends T>) pt.getActualTypeArguments()[0];
     }

    protected Session currentSession() {
        return sessionFactory.getCurrentSession();
    }

    @Override
    public PK create(T t) {
        return (PK) currentSession().save(t);

    }

    @Override
    public T read(PK id) {
        return (T) currentSession().get(entityClass, id);
    }

    @Override
    public void update(T t) {
        currentSession().saveOrUpdate(t);   
    }

    @Override
    public void delete(T t) {
        currentSession().delete(t);

    }

    @Override
    public List<T> getAll() {
        return currentSession().createCriteria(entityClass).list();
    }

    @Override
    public void createOrUpdate(T t) {
        currentSession().saveOrUpdate(t);   
    }

GenericServiceImpl

@Service
public abstract class GenericServiceImpl<T, PK extends Serializable> implements IGenericService<T, PK>{

     private IGenericDao<T, PK> genericDao;

    public GenericServiceImpl(IGenericDao<T,PK> genericDao) {
        this.genericDao=genericDao;
    }

    public GenericServiceImpl() {
    }


    @Override
    @Transactional(propagation = Propagation.REQUIRED)
    public PK create(T t) {
        return create(t);
    }

    @Override
    @Transactional(propagation = Propagation.REQUIRED, readOnly = true)
    public T read(PK id) {
        return genericDao.read(id);
    }

    @Override
    @Transactional(propagation = Propagation.REQUIRED)
    public void update(T t) {
        genericDao.update(t);
    }

    @Override
    @Transactional(propagation = Propagation.REQUIRED)
    public void delete(T t) {
        genericDao.delete(t);

    }

    @Override
    @Transactional(propagation = Propagation.REQUIRED)
    public void createOrUpdate(T t) {
        genericDao.createOrUpdate(t);   
    }

    @Override
    @Transactional(propagation = Propagation.REQUIRED, readOnly = true)
    public List<T> getAll() {
        return genericDao.getAll();
    }

}

ProjectDaoImpl

@Repository
public class ProjectDaoImpl extends GenericDaoImpl<Project, Integer> implements IProjectDao{

}

ProjectServiceImpl

@Service
public class ProjectServiceImpl extends GenericServiceImpl<Project, Integer> implements IProjectService {


    @Autowired
    public ProjectServiceImpl(@Qualifier("projectDaoImpl") IGenericDao<Project, Integer> genericDao) {
        super(genericDao);
    }

}

ProjectController

public class ProjectController {

     @Autowired(required = true)
     private IProjectService projectService;

    @RequestMapping(value = "/projects", method = RequestMethod.GET)
    public String listProjects(Model model){
        model.addAttribute("project", new Project());
        model.addAttribute("listProjects", projectService.getAll());
        return "project";
    }

    //for add and update role both
    @RequestMapping(value = "/project/add", method = RequestMethod.POST)
    public String addProject(@ModelAttribute("project") Project p){
        if( p.getId() == 0){
            //new role, add it
            projectService.create(p);
        } else {
            //existing role, call update
           projectService.update(p);
        }
        return "redirect:/projects";
    }

    @RequestMapping("/remove/{id}")
    public String deleteProject(@PathVariable("id") int id){
        projectService.delete(projectService.read(id));
        return "redirect:/projects";
    }

    @RequestMapping("edit/{id}")
    public String editProject(@PathVariable("id") int id, Model model){
        model.addAttribute("project", projectService.read(id));
        model.addAttribute("listProjects", projectService.getAll());

        return "project";
    }

}

What do you think `public PK create(T t) { return create(t); }` does and why do you think so? Or asked differently: Why don't you think it is calling itself? How long do you have to sit there and stare at that line of code, which is **clearly highlighted by the error message**, to see that you probably forgot to qualify call with `genericDao.`? — Andreas, Jan 19 '17 at 21:10
Possible duplicate of [What is a StackOverflowError?](http://stackoverflow.com/questions/214741/what-is-a-stackoverflowerror) — Joe C, Jan 19 '17 at 21:32

score 1 · Answer 1 · answered Jan 19 '17 at 21:31

@Override
@Transactional(propagation = Propagation.REQUIRED)
public PK create(T t) {
    return create(t);
}

This method is calling itself unconditionally. This can only result in a StackOverflowError.

Did you mean to do this?

@Override
@Transactional(propagation = Propagation.REQUIRED)
public PK create(T t) {
    return genericDao.create(t);
}

Generic DAO cause stack overflow

1 Answers1