Question

我尝试使用java和hibernate来扩展一个小应用程序，当我运行此应用程序的测试类时，我收到此错误消息：

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
Hibernate: insert into REUNION (TITREREUNION, DATEREUNION) values (?, ?)
Hibernate: insert into REUNION (TITREREUNION, DATEREUNION) values (?, ?)
Hibernate: insert into REUNION (TITREREUNION, DATEREUNION) values (?, ?)
Exception in thread "main" java.lang.ClassCastException: org.hibernate.impl.QueryImpl     cannot be cast to javax.persistence.Query
at metier.MetierImpl.getAllReunion(MetierImpl.java:62)
at Test.main(Test.java:21)

如您所见，错误是MetierImpl类：导致错误的方法是：

 public Reunion getAllReunion(){

    Session session =sessionFactory.getCurrentSession();
    session.beginTransaction();
    Query req=(Query) session.createQuery("select R  from Reunion ");
    List<Reunion> list = req.getResultList();
    Reunion r=(Reunion) req.getResultList().get(0);

    return r;


}

Answer 1

Hibernate Session.createQuery()返回org.hibernate.Query的实例。您的代码将此对象强制转换为javax.persistence.Query，但它不是javax.persistence.Query的实例。所以你得到了这个例外。

不要进行此转换，并导入正确的Query类：不是javax.persistence.Query，而是org.hibernate.Query。

hibernate错误：java.lang.ClassCastException：org.hibernate.impl.QueryImpl无法强制转换为javax.persistence.Query

1 个答案: