Iterate over your whole DB using hibernate

In this post I'll assume you already have your hibernate object corresponding to your DB schema.

What will we try to achieve here?
I will iterate all of the DB using hibernate objects, and here is a little java program which will attempt to achieve just that:

import org.hibernate.cfg.AnnotationConfiguration;

import org.hibernate.HibernateException;

import org.hibernate.SessionFactory;

import org.hibernate.Session;

import org.hibernate.Query;

import org.hibernate.metadata.ClassMetadata;

import java.util.Map;

/**

* Created by IntelliJ IDEA.

* User: avih

* Date: May 11, 2010

* Time: 7:43:37 AM

*/

public class Main {

private static final SessionFactory ourSessionFactory;

static {

try {

ourSessionFactory = new AnnotationConfiguration().

configure("hibernate.cfg.xml").

buildSessionFactory();

}

catch (Throwable ex) {

throw new ExceptionInInitializerError(ex);

}

}

public static Session getSession() throws HibernateException {

return ourSessionFactory.openSession();

}

public static void main(final String[] args) throws Exception {

final Session session = getSession();

try {

System.out.println("querying all the managed entities...");

final Map metadataMap = session.getSessionFactory().getAllClassMetadata();

for (Object key : metadataMap.keySet()) {

final ClassMetadata classMetadata = (ClassMetadata) metadataMap.get(key);

final String entityName = classMetadata.getEntityName();

final Query query = session.createQuery("from " + entityName);

System.out.println("executing: " + query.getQueryString());

int index = 0;

for (Object o : query.list()) {

index++;

//System.out.println("index: " + o);

}

System.out.println("Contains " + index + " Objects\n");

}

}

finally {

session.close();

}

}

}