A dao implementation that consolidates CRUD operations using Java generics

consolidated-dao-generics.java

@Repository("baseDAO")
public abstract class BaseDAOImpl<T, ID extends Serializable> implements IBaseDAO<T, ID> {

	@Autowired
	protected SessionFactory sessionFactory; //injected by Spring container
	@SuppressWarnings("unchecked")
	private Class<T> clazz;

	@SuppressWarnings("unchecked")
	public BaseDAOImpl() {
		this.clazz = (Class<T>)
			  ((ParameterizedType) getClass().getGenericSuperclass())
					.getActualTypeArguments()[0];
	}

	/** snipped boring CRUD **/

	@SuppressWarnings("unchecked")
	public List<T> findByExample(T exampleInstance, String[] excludeProperty) {
		Criteria crit = this.sessionFactory.getCurrentSession().createCriteria(this.clazz);
		Example example = Example.create(exampleInstance);
			for (String exclude : excludeProperty) {
			example.excludeProperty(exclude);
		}
		crit.add(example);
		return crit.list();
	}

	/**
	*  Convenience criteria method.
	*/
	@SuppressWarnings("unchecked")
	protected List<T> findByCriteria(Criterion...criterion) {
		Criteria crit = this.getSessionFactory().getCurrentSession().createCriteria(this.clazz);

		for (Criterion c : criterion) {
			crit.add(c);
		}
		return crit.list();
	}
}