My requirement is as follows:
I need to restart(or rebuild) hibernate session factory in my Spring web application at frequent intervals with the new HBM files I get from outside.
Currently my Sessionfactory class is as follows with a SessionFactory Proxy to intercept 'OpenSession' call.
There I am checking for a condition to restart and rebuilding sessionFactory.
My problem here is , in concurrent environment the other users who are in middle of other transaction is getting affected during this restart.
Is there anyway to carryout the restart by checking all the transactions and open sessions and carry out rebuilding session factory once all other completes?
or any other solution exists.
Code:
public class DataStoreSessionFactory extends LocalSessionFactoryBean
{
private boolean restartFactory = false;
@Override
protected void postProcessConfiguration(Configuration config) throws HibernateException
{
super.postProcessConfiguration(config);
updateHBMList(config);
}
private void updateHBMList(final Configuration config)
{
config.addXML(modelRegistry.generateMapping());
}
@Override
public SessionFactory getObject()
{
Object obj = super.getObject();
/*
* Invocation handler for the proxy
*/
SessionFactoryProxy proxy = new SessionFactoryProxy(this, (SessionFactory) obj);
/**
* All the methods invoked on the returned session factory object will pass through this proxy's invocation
* handler
*/
SessionFactory sessionFactory = (SessionFactory) Proxy.newProxyInstance(getClass().getClassLoader(),
new Class[] { SessionFactory.class },
proxy);
return sessionFactory;
}
static class SessionFactoryProxy implements InvocationHandler
{
private SessionFactory sessionFactory;
private LocalSessionFactoryBean factoryBean;
public SessionFactoryProxy(LocalSessionFactoryBean factoryBean, SessionFactory sessionFactory)
{
this.factoryBean = factoryBean;
this.sessionFactory = sessionFactory;
}
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable
{
/**
* Only if the method invoked is openSession - check if the session factory should be restarted, and only then
* invoke the requested method
*/
if (method.getName().equals("openSession"))
{
restartSessionFactoryIfNecessary();
}
return method.invoke(sessionFactory, args);
}
private void restartSessionFactoryIfNecessary()
{
restartSessionFactory();
/*if (((DataStoreSessionFactory) factoryBean).isRestartFactory())
{
restartSessionFactory();
}*/
}
private synchronized void restartSessionFactory()
{
log.info("Restarting session...");
factoryBean.destroy();
try
{
factoryBean.afterPropertiesSet();
sessionFactory = factoryBean.getObject();
}
catch (Exception e)
{
log.error("Error while restarting session: " + e.getMessage());
throw new RuntimeException(e);
}
}
}
Thanks, Appasamy