org.springframework.orm.hibernate
Interface HibernateCallback

public interface HibernateCallback

Callback interface for Hibernate code. To be used with HibernateTemplate's execute method, assumably often as anonymous classes within a method implementation. The typical implementation will call Session.load/find/save/update to perform some operations on persistent objects. It can also perform direct JDBC operations via Hibernate's Session.connection() method, returning the active JDBC connection.

Note that Hibernate works on unmodified plain Java objects, performing dirty detection via copies made at load time. Returned objects can thus be used outside of an active Hibernate Session without any hassle, e.g. for display in a web GUI. Reassociating such instances with a new Session, e.g. for updates when coming back from the GUI, is straightforward, as the instance has kept its identity. You should care to reassociate them as early as possible though, to avoid having already loaded a version from the database in the same Session.

Since:

02.05.2003

Author:

Juergen Hoeller

See Also:

HibernateTemplate

Method Summary

java.lang.Object

doInHibernate(net.sf.hibernate.Session session) Gets called by HibernateTemplate.execute with an active Hibernate Session.

Method Detail

doInHibernate

public java.lang.Object doInHibernate(net.sf.hibernate.Session session)
                               throws net.sf.hibernate.HibernateException,
                                      java.sql.SQLException

Gets called by HibernateTemplate.execute with an active Hibernate Session. Does not need to care about activating or closing the Session, or handling transactions.

If called without a thread-bound Hibernate transaction (initiated by HibernateTransactionManager), the code will simply get executed on the underlying JDBC connection with its transactional semantics. If Hibernate is configured to use a JTA-aware DataSource, the JDBC connection and thus the callback code will be transactional if a JTA transaction is active.

Allows for returning a result object created within the callback, i.e. a domain object or a collection of domain objects. Note that there's special support for single step actions: see HibernateTemplate.find etc. A thrown RuntimeException is treated as application exception, it gets propagated to the caller of the template.

Parameters:

session - active Hibernate session

Returns:

a result object, or null if none

Throws:

net.sf.hibernate.HibernateException - in case of Hibernate errors

java.sql.SQLException - in case of errors on direct JDBC access

See Also:

HibernateTemplate.execute(org.springframework.orm.hibernate.HibernateCallback), HibernateTransactionManager