如何避免“具有相同ID的其他对象。”？

Question

I am using:

• Web App (a filter opens session. DAO uses getCurrentSession())
• Hibernate
• Spring (AOP configuration over Service)
• xml configuration for all
• DTO between Mbean and Service

Well, I have two methods (business service):

• service.findUser(..DTO..)
• service.updateUser(..DTO..)

update throws org.hibernate.NonUniqueObjectException exception. How can I avoid that? I need to use update, not merge.

Thanks in advance.

//MBean.java method
public void testUpdateUser(ActionEvent e) {
    System.out.println(name);
    ServiceResponse<UserDto> serviceResponse = super.getPrincipalService().findUser(name);
    UserDto userDto = serviceResponse.getResponseList().get(0);
//update some properties here
        serviceResponse = super.getPrincipalService().updateUser(userDto);
        LOG.info("" + serviceResponse);
}
    //Service.java: update method
    public ServiceResponse<UserDto> updateUser(UserDto userDto) {
        LOG.info("");
        ServiceResponse<UserDto> serviceResponse = new ServiceResponse<UserDto>();
        try {
            User user = this.getGlobalMapper().map(userDto, User.class);
            //
            this.getUserDao().update(user);
            userDto = this.getGlobalMapper().map(user, UserDto.class);
            serviceResponse.getResponseList().add(userDto);
            serviceResponse.setOperationCodeResponse(ServiceResponseCode.OK);
            serviceResponse.getMessages().add("Operacion OK");
        } catch (Exception e) {
            serviceResponse.getMessages().add(e.getMessage());
            serviceResponse.setOperationCodeResponse(ServiceResponseCode.MODEL_ERROR);
            LOG.error("", e);
        }
        return serviceResponse;
    }
    //Exception result
org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session: [com.softlogia.copi.model.domain.User#155]
    at org.hibernate.engine.internal.StatefulPersistenceContext.checkUniqueness(StatefulPersistenceContext.java:696)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.performUpdate(DefaultSaveOrUpdateEventListener.java:296)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsDetached(DefaultSaveOrUpdateEventListener.java:241)
    at org.hibernate.event.internal.DefaultUpdateEventListener.performSaveOrUpdate(DefaultUpdateEventListener.java:55)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:90)
    at org.hibernate.internal.SessionImpl.fireUpdate(SessionImpl.java:705)
    at org.hibernate.internal.SessionImpl.update(SessionImpl.java:697)
    at org.hibernate.internal.SessionImpl.update(SessionImpl.java:693)

Answer 1

I am assuming you are using pure Hibernate as ORM; simply put, regardless of the status of your db, you have in your current Hibernate session different copies of the same row. To resolve this you can:

1) flush() the hibernate session after every writing operation on db (insert or update)

OR

2) In your update metod call merge() instead of saveOrUpdate()