SSJ SpringMVC3+JPA2.0(Hibernate4)+FreeMarker

package com.web.base; import java.lang.reflect.ParameterizedType; import java.util.Collections; import java.util.List; import javax.persistence.EntityManager; import javax.persistence.PersistenceContext; import javax.persistence.Query; @SuppressWarnings("unchecked") public class BaseDaoImpl<T> implements BaseDao<T> { @PersistenceContext private EntityManager em; private Class<T> clazz;// 类对象 public BaseDaoImpl() { // 通过发射获取T的真实类型 // 通过反射获取当前类表示的实体的直接父类的Type ParameterizedType pt = (ParameterizedType) this.getClass().getGenericSuperclass(); // 返回参数数组 this.clazz = (Class<T>) pt.getActualTypeArguments()[0]; } @Override public void save(T entity) { em.persist(entity); } @Override public void delete(String id) { em.remove(getById(id)); } @Override public void update(T entity) { em.merge(entity); } @Override public T getById(String id) { if (id == null) { return null; } return em.find(clazz, id); } @Override public List<T> getByIds(String[] ids) { if (ids == null || ids.length == 0) { return Collections.EMPTY_LIST; } return em.createQuery("from " + clazz.getSimpleName() + " where id in(ids)").setParameter("ids", ids).getResultList(); } @Override public List<T> findAll() { return em.createQuery("from " + clazz.getSimpleName()).getResultList(); } @Override /** * 批处理 */ public void batchEntityByHQL(String hql, Object... objects) { Query query = em.createQuery(hql); for (int i = 0; i < objects.length; i++) { query.setParameter(i, objects[i]); } query.executeUpdate(); } @Override public List<T> batchResultsByHQL(String hql, Object... objects) { Query query = em.createQuery(hql); for (int i = 0; i < objects.length; i++) { query.setParameter(i, objects[i]); } return query.getResultList(); } @Override public T batchUniqueResultByHQL(String hql, Object... objects) { Query query = em.createQuery(hql); for (int i = 0; i < objects.length; i++) { query.setParameter(i, objects[i]); } return (T) query.getSingleResult(); } }