| This interceptor binds a new Hibernate Session to the thread before a method
call, closing and removing it afterwards in case of any method outcome.
If there already is a pre-bound Session (e.g. from HibernateTransactionManager,
or from a surrounding Hibernate-intercepted method), the interceptor simply
participates in it.
Application code must retrieve a Hibernate Session via the
SessionFactoryUtils.getSession method, to be able to detect a
thread-bound Session. It is preferable to use getSession with
allowCreate=false, if the code relies on the interceptor to provide proper
Session handling. Typically, the code will look like as follows:
public void doSomeDataAccessAction() {
Session session = SessionFactoryUtils.getSession(this.sessionFactory, false);
try {
...
}
catch (HibernateException ex) {
throw SessionFactoryUtils.convertHibernateAccessException(ex);
}
}
Note that the application must care about handling HibernateExceptions itself,
preferably via delegating to the SessionFactoryUtils.convertHibernateAccessException
method that converts them to exceptions that are compatible with the
org.springframework.dao exception hierarchy (like HibernateTemplate does).
Unfortunately, this interceptor cannot convert checked HibernateExceptions
to unchecked dao ones transparently. The intercepted method would have to declare
the checked HibernateException - thus the caller would still have to catch or
rethrow it, even if it will never be thrown if intercepted. Any such exception
will nevertheless get converted by default.
This class can be considered a declarative alternative to HibernateTemplate's
callback approach. The advantages are:
- no anonymous classes necessary for callback implementations;
- the possibility to throw any application exceptions from within data access code.
The drawbacks are:
- the dependency on interceptor configuration;
- the delegating try/catch blocks.
Note: Spring's Hibernate support in this package requires Hibernate 2.1.
Dedicated Hibernate3 support can be found in a separate package:
org.springframework.orm.hibernate3.
author:
Juergen Hoeller
since:
13.06.2003
See Also: SessionFactoryUtils.getSession
See Also: HibernateTransactionManager
See Also: HibernateTemplate | 