Hibernate Migration from 4.3.x to 5.x for method org.hibernate.cfg.Configuration.getClassMapping(className)

Question

In Hibernate 4.3.x, there is a method getClassMapping(className) of class org.hibernate.cfg.Configuration. But in Hibernate 5.x, this getClassMapping(className) method is removed from Configuration class.

What will be the code substitution in Hibernate-5?

Please help on this migration issue.

Chil

Do you need it while bootstrapping or at runtime? – Kinshasa

No, I have implemented custom caching mechanism. So I need it after bootstrapping when queries are fired. Link http://docs.jboss.org/hibernate/orm/5.0/userGuide/en-US/html_single/#bootstrap is helpful if I need to retrieve or build metadata or sessionFactory. But steps after bootstrapping is not given in documentation. – Chil

ClassMetadata isn't enough? You can get it from SessionFactory via ClassMetadata getClassMetadata(String entityName). – Kinshasa

No ClassMetadata is not enough. Need PersistentClass from metadata. – Chil

Answer 1

I posted to Broadleaf Commerce because they also needed PersistentClass:

I've been tooling with Hibernate 5, and some of these changes .... To get metadata now use the Serviceloader:

package org.broadleafcommerce.openadmin.server.dao;

import org.hibernate.boot.SessionFactoryBuilder;
import org.hibernate.boot.spi.MetadataImplementor;
import org.hibernate.boot.spi.SessionFactoryBuilderFactory;
import org.hibernate.boot.spi.SessionFactoryBuilderImplementor;

public class EntityMetaData implements SessionFactoryBuilderFactory {

    private static final ThreadLocal<MetadataImplementor> meta = new ThreadLocal<>();

    @Override
    public SessionFactoryBuilder getSessionFactoryBuilder(MetadataImplementor metadata, SessionFactoryBuilderImplementor defaultBuilder) {
        meta.set(metadata);
        return defaultBuilder;
    }

    public static MetadataImplementor getMeta() {
        return meta.get();
    }
}

You will need the file:

/resources/META-INF/services/org.hibernate.boot.spi.SessionFactoryBuilderFactory

with the fully qualified class name, which in my example is:

org.broadleafcommerce.openadmin.server.dao.EntityMetaData

Kamseen

Thanks, above solution worked. I made only one change in EntityMetaData class i.e., instead of using ThreadLocal, I used HashMap to store metadata object. – Chil

How is the getSessiongFactoryBuilder method getting executed? So that I can call getMeta() to get the MetadataImplementor. Is EntityMetaData to be injected into Hibernate in some way? Sorry don't understand... – Cabretta

@NiravPatel@Kamseen Can you please share the complete solution for this problem as I am unable to implement. – Beria

I did exactly that and even though I debugged it and made sure that this class is actually gets called, when I call EntityMetaData.get() it returns null, why??. Also when I replace ThreadLocal<MetadataImplementor> meta with just MetadataImplementor and directly assign it it works. – Gaylagayle

Answer 2

Get an object of PersisterCreationContext and then try this :-

PersistentClass persistentClass = 
persisterCreationContext.getMetadata().getEntityBinding(className);

Pls check this link (Example 3.8. Native Bootstrapping - Putting it all together) to understand how to get standardRegistry, metadata and sessionFactory in Hibernate 5.x

Now as we were pulling metadata from persisterCreationContext and now we already had it so we can right away get the required PersistentClass object of any entity by

SessionFactory sessionFactory = metadata.getSessionFactoryBuilder().build();
PersistentClass persistentClass = metadata.getEntityBinding(className);

Testy

How to retrieve persisterCreationContext? Can you please update answer with proper steps. i.e., normally we`ll have sessionFactory object or configuration object, so how can we retrieve PersisterCreationContext from it? – Chil

I need reverse of what is suggested in link. Is there any way to retrieve metadata from org.springframework.orm.hibernate5.LocalSessionFactoryBean or org.hibernate.SessionFactory object? – Chil

As in hibernate-4.x, getClassMapping(className) method is in Configuration class. So i`m having configuration object only. As now in hibernte-5.x this method is removed from class, I need to retrieve metadata or persisterCreationContext from configuration object. – Chil

I could think about one solution is if you write an ASPECT around the constructor of class org.hibernate.internal.SessionFactoryImpl. So as soon it gets invoked while system gets loaded you can get handle of the metaData for your task. Constructor is :- public SessionFactoryImpl(final MetadataImplementor metadata, SessionFactoryOptions options) {} – Testy

Is it possible to retrieve constructor param and store it in custom class bean using Aspect Oriented Programming? – Chil

Answer 3

In Hibernate 3 and 4 you would do something like this

URL configFileURL = getResource(); //some method to get hold of the location of your hibernate.cfg.xml
Configuration configuration = (new Configuration()).configure(configFileURL);
Iterator classMappings = configuration.getClassMappings();
  while (classMappings.hasNext()) {
    PersistentClass persistentClass = (PersistentClass) classMappings.next();
    //do somthing 
    }

In Hibernate 5 initialise Metadata like this

URL configFileURL = getResource(); //some method to get hold of the location of your hibernate.cfg.xml
StandardServiceRegistry standardRegistry = new StandardServiceRegistryBuilder().configure(configFileURL).build();
Metadata metaData = new MetadataSources(standardRegistry).getMetadataBuilder().build();

And use getEntityBindings() on metadata

Collection<PersistentClass> entityBindings = metadata.getEntityBindings();
Iterator<PersistentClass> iterator = entityBindings.iterator();
  while (iterator.hasNext()) {
    PersistentClass persistentClass = iterator.next();    
    //do somthing
  }

Cabretta

Answer 4

This is discussed in the Hibernate 5.0 Migration Guide as well as the Bootstrap chapter in the Hibernate User Guide (see especially the "Legacy Bootstrapping" appendix).

In short, while Configuration is still supported for straight-line bootstrapping, if you want to "hook into" the bootstrap process you are going to have to use the new bootstrap APIs.

Scheers

Bootstrapping links are broken, and Migration Guide link currently points to an empty 5.4 migration document. – Cecilia