Java tutorial
/* * To change this license header, choose License Headers in Project Properties. * To change this template file, choose Tools | Templates * and open the template in the editor. */ package hibernate; import java.io.Serializable; import java.lang.reflect.ParameterizedType; import java.util.List; import org.hibernate.Criteria; import org.hibernate.LockMode; import org.hibernate.Session; import org.hibernate.criterion.Criterion; import org.hibernate.criterion.Example; /** * * @author root */ public abstract class GenericHibernateDAO<T, ID extends Serializable> implements GenericDAO<T, ID> { private Class<T> persistentClass; private Session session; public GenericHibernateDAO() { this.persistentClass = (Class<T>) ((ParameterizedType) getClass().getGenericSuperclass()) .getActualTypeArguments()[0]; } @SuppressWarnings("unchecked") public void setSession(Session s) { this.session = s; } protected Session getSession() { if (session == null) throw new IllegalStateException("Session has not been set on DAO before usage"); return session; } public Class<T> getPersistentClass() { return persistentClass; } @SuppressWarnings("unchecked") public T findById(ID id, boolean lock) { T entity; if (lock) //entity = (T) getSession().load(getPersistentClass(), id, LockMode.UPGRADE); entity = (T) getSession().get(getPersistentClass(), id, LockMode.UPGRADE); else //entity = (T) getSession().load(getPersistentClass(), id); entity = (T) getSession().get(getPersistentClass(), id); return entity; } @SuppressWarnings("unchecked") public List<T> findAll() { return findByCriteria(); } @SuppressWarnings("unchecked") public List<T> findByExample(T exampleInstance, String[] excludeProperty) { Criteria crit = getSession().createCriteria(getPersistentClass()); Example example = Example.create(exampleInstance); for (String exclude : excludeProperty) { example.excludeProperty(exclude); } crit.add(example); return crit.list(); } @SuppressWarnings("unchecked") public T makePersistent(T entity) { getSession().saveOrUpdate(entity); return entity; } public void makeTransient(T entity) { getSession().delete(entity); } public void flush() { getSession().flush(); } public void clear() { getSession().clear(); } /** * Use this inside subclasses as a convenience method. */ @SuppressWarnings("unchecked") protected List<T> findByCriteria(Criterion... criterion) { Criteria crit = getSession().createCriteria(getPersistentClass()); for (Criterion c : criterion) { crit.add(c); } return crit.list(); } }