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我实现与反思众所周知通用的DAO模式(由凯文·鲍尔索克斯):通用DAO和org.hibernate.MappingException:未知实体:java.lang.Object继承
public class NewBaseDaoImpl<T, ID extends Serializable> implements NewBaseDao<T,ID> {
private Class<T> entity;
@PersistenceContext(unitName = "orm-unit")
private EntityManager em;
@SuppressWarnings("unchecked")
public NewBaseDaoImpl(){
this.entity = (Class<T>)((ParameterizedType) getClass().getGenericSuperclass()).getActualTypeArguments()[0];
}
@Override
public T read(ID id) {
return em.find(this.getEntity(), id);
}
插入数据工作正常,但当我尝试通过ID找到一个实体,像这样:
RepairShop rs = (RepairShop) bean.read(1L);
我得到:
java.lang.IllegalArgumentException异常:未知的实体:java.lang.Object继承 (org.hibernate.MappingExceptio n:未知实体:java.lang.Object)
什么错?