Generic DAO

package net.example.com.dao;

import java.util.List;

public interface GenericDao<T> {
    public T findById(int id);
    public List<T> findAll();
    public void update(T entity);
    public void save(T entity);
    public void delete(T entity);
}

/* ------------------------------------------------------ */

package net.example.com.dao;

import java.io.Serializable;
import java.util.List;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Scope;

@Scope("prototype")
public abstract class GenericHibernateDaoImpl<T extends Serializable> implements GenericDao<T> {

    private Class<T> clazz;

    @Autowired
    private SessionFactory sessionFactory;

    public final void setClazz(Class<T> clazzToSet) {
        this.clazz = clazzToSet;
    }

    @SuppressWarnings("unchecked")
    public T findById(int id) {
        return (T) getCurrentSession().get(clazz, id);
    }

    @SuppressWarnings("unchecked")
    public List<T> findAll() {
        return getCurrentSession().createQuery("FROM " + clazz.getName()).list();
    }

    public void update(T entity) {
        getCurrentSession().update(entity);
    }

    public void save(T entity) {
        getCurrentSession().save(entity);
    }

    public void delete(T entity) {
        getCurrentSession().delete(entity);
    }

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

/* ------------------------------------------------------ */

package net.example.com.dao;

import java.util.List;

import net.example.com.entity.User;

public interface UserDao extends GenericDao<User> {

    public User findByEmail(String email);

    public List<User> findEnabled();
}

/* ------------------------------------------------------ */

package net.example.com.dao;

import java.util.List;

import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

import net.example.com.entity.User;

@Repository
public class UserDaoImpl extends GenericHibernateDaoImpl<User> implements UserDao {

    public User findByEmail(String email) {
        return (User) getCurrentSession()
                .createQuery("FROM User WHERE email = :email")
                .setString("email", email).uniqueResult();
    }

    @SuppressWarnings("unchecked")
    public List<User> findEnabled() {
        return getCurrentSession()
                .createQuery("FROM User WHERE enabled = true")
                .list();
    }
}