Re: Spring+Hibernate - obsluha vyjimek databaze

Mon, 05 Jun 2006 05:15:24 -0700 

Petr Gola wrote:


Bohuzel, stale se nemohu dobrat k vysledku.




Pricina je ta, ze Hibernate neprovede operaci v databazi ihned, ale az 
pri ukonceni transakce (to je defaultni chovani), kdy se pokusi provest 
vsechny zmeny najednou. V tomto pripade je pouzito Spring AOP, kdy se 
commit provede pri ukonceni metody (viz ten stack trace) - a v tom 
okamziku se vygeneruje vyjimka. Takze try-catch block uvnitr samozrejme 
nic nechyti.


Resenim je provest flush explicitne:
getHibernateTemplate().flush()


Take se da Hibernate nakonfigurovat aby flushoval vzdy, ale to ma smysl 
jen pokud takovych situaci bude vice (a pak by mozna nebylo od veci 
zamysleni, proc je business logika v databazi pod ORM).



implementace DAO:


public class UserHibernateDAO extends HibernateDaoSupport implements 
IUserDAO {

 public User saveUser(User usr) {
   getHibernateTemplate().saveOrUpdate(usr);
   return usr;
 }
 ...
}

SLUZBA:

public class UserSpringService implements IUserService {
 private IUserDAO userDAO;

 public User saveUser(User usr) {
   try {
     usr = userDAO.saveUser(usr);
   } catch (DataAccessException daex) {
     System.out.println("daex:"+daex);
     throw new ExistingUsernameException("Existing username!");
   }
   return usr;
 }
 ...
}

No, bohuzel nevim, kde je problem, ale zadna ExistingUsernameException
vyhozena neni, Tomcat vypise:

(def.AbstractFlushingEventListener   300 ) Could not synchronize
database state with session
org.hibernate.exception.ConstraintViolationException: Could not
execute JDBC batch update

at 
org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:71) 

at 
org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43) 

at 
org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:202)

at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:235)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:139)

at 
org.hibernate.event.def.AbstractFlushingEventListener.performExecutions

at org.hibernate.event.def.DefaultFlushEventListener.onFlush
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:985)
at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:333)

at 
org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:106) 

at 
org.springframework.orm.hibernate3.HibernateTransactionManager.doCommit

at org.springframework.transaction.support.AbstractPlatform...

at 
org.springframework.transaction.support.AbstractPlatformTransactionManager.commit 

at 
org.springframework.transaction.interceptor.TransactionAspectSupport.doCommit... 

at 
org.springframework.transaction.interceptor.TransactionInterceptor.invoke

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke
at $Proxy1.saveUser(Unknown Source)

Ale pokud zavolam z klienta volam

try { userService.saveUser(usr) } catch(DataAccessException daex) ... 
dostanu


daex:org.springframework.dao.DataIntegrityViolationException:
Hibernate operation: Could not execute JDBC batch update; SQL [insert
into ...

Ale chtel bych tuto vyjimku osterit uz na strane serveru.




--
Kamil Podlesak <[EMAIL PROTECTED]>























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