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我有一個java代碼,我正在更新員工實體。我正在使用應用程序管理實體管理器。我在登錄頁面有一個條件,如果用戶提供了正確的用戶名/密碼,他的最後登錄時間將被更新。管理實體越來越分離
但更新不會發生,我得到一個異常的實體已經detached.Please看到下面的代碼: -
GenericDaoImpl.java
public class GenericDaoImpl<T> implements GenericDao<T> {
private static final String PERSISTENCE_UNIT_NAME = "expenseCalculator";
private static EntityManagerFactory factory;
protected static EntityManager em;
private EntityTransaction etr;
protected Class<T> domainClass;
/** The domain object name. */
protected String domainObjectName = null;
public synchronized static EntityManagerFactory getfactory(){
if (null == factory) {
factory = Persistence.createEntityManagerFactory(PERSISTENCE_UNIT_NAME);
}
return factory;
}
@SuppressWarnings("unchecked")
public GenericDaoImpl() {
em = getfactory().createEntityManager();
domainClass = (Class<T>) ((ParameterizedType) getClass().getGenericSuperclass()).getActualTypeArguments()[0];
Entity entityAnn = (Entity) domainClass.getAnnotation(Entity.class);
if (entityAnn != null && !entityAnn.name().equals("")) {
domainObjectName = entityAnn.name();
} else {
domainObjectName = domainClass.getSimpleName();
}
}
public T create(T t) {
etr = em.getTransaction();
etr.begin();
em.persist(t);
etr.commit();
return t;
}
}
StaffServiceImpl.java
public Staff authenticateStaff(LoginBean loginBean) {
staff = staffDao.findUnique(loginBean.getUserName());
if (null != staff) {
if (staff.getIsBlocked() == 'N' && staff != null && staff.getUserName().equals(loginBean.getUserName())
&& staff.getPassword().equals(loginBean.getPassword())) {
staff.setLastLogin(new Date());
//This is giving an exception..
new StaffDaoImpl().create(staff);
return staff;
} else if (staff.getIsBlocked() == 'N' && staff != null
&& staff.getUserName().equals(loginBean.getUserName())) {
updateUnsuccessfulAttemptsAndBlockedStatus(staff);
}
}
return null;
}
StaffDaoImpl.java: -
@Repository
@Component
public class StaffDaoImpl extends GenericDaoImpl<Staff> implements StaffDao {
public Staff findUnique(String userName) {
TypedQuery<Staff> query = em.createNamedQuery(domainObjectName + ".findByUserName", domainClass);
query.setParameter("username", userName);
Staff staff = null;
try {
staff = query.getSingleResult();
} catch (NoResultException e) {
staff = null;
}
return staff;
}
在Class StaffServiceImpl.java中,您將看到我已經讓人員實體管理您調用了「staffDao.findUnique(loginBean.getUserName());」但是它仍然讓我體會到實體職員是獨立的。任何幫助,高度讚賞。
你得到什麼異常究竟 –
org.hibernate.PersistentObjectException:?脫離實體被persist:com.expensecalculator.domain.Staff \t在org.hibernate.event.internal.DefaultPersistEventListener.onPersist( DefaultPersistEventListener.java:124) \t at org.hibernate.event.internal.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:58) \t在org.hibernate.internal.SessionImpl.firePersist(SessionImpl.java:778) \t在org.hibernate.internal.SessionImpl.persist(SessionImpl.java:751) \t在org.hibernate.internal.SessionImpl.persist( SessionImpl.java:756) –
由於這是一個更新,你可以考慮使用'merge'而不是'persist' – Pelocho