अन्य टूल्स का प्रयास किया और समस्याएं थीं। मेरा घर लुढ़का हुआ समाधान यहाँ है। कुछ सफाई की जरूरत हो सकती है, लेकिन इसका मांस वहां है।
import java.io.Serializable;
import java.util.List;
import java.util.logging.Logger;
import lombok.Getter;
import lombok.RequiredArgsConstructor;
import lombok.Setter;
import org.hibernate.Session;
import org.hibernate.Transaction;
import ca.digitalrapids.lang.GeneralException;
import ca.digitalrapids.mediamanager.server.dao.hibernate.GenericDAOHibernate;
import ca.digitalrapids.mediamanager.server.dao.hibernate.GenericDAOHibernate.GenericDAOHibernateFactory;
import ca.digitalrapids.persist.dao.DAOOptions;
import ca.digitalrapids.persist.hibernate.HibernateUtil2;
import com.google.common.collect.ImmutableMultimap;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Sets;
@RequiredArgsConstructor
public class DataMigrator
{
private static final Logger logger = Logger
.getLogger(DataMigrator.class.getName());
private final HibernateUtil2 sourceHibernateUtil2;
private final HibernateUtil2 destHibernateUtil2;
private final ImmutableSet<Class<?>> beanClassesToMigrate;
@Setter @Getter
private Integer copyBatchSize = 10;
@Setter
private GenericDAOHibernateFactory sourceDaoFactory =
new GenericDAOHibernate.GenericDAOHibernateFactoryImpl();
@Setter
private GenericDAOHibernateFactory destDaoFactory =
new GenericDAOHibernate.GenericDAOHibernateFactoryImpl();
private final ImmutableMultimap<Class<?>, Class<?>> entityDependencies;
public void run() throws GeneralException
{
migrateData(sourceHibernateUtil2.getSession(),
destHibernateUtil2.getSession());
}
private void migrateData(Session sourceSession, Session destSession)
throws GeneralException
{
logger.info("\nMigrating data from old HSQLDB database.\n");
Transaction destTransaction = null;
try
{
destTransaction = destSession.beginTransaction();
migrateBeans(sourceSession, destSession, beanClassesToMigrate,
entityDependencies);
destTransaction.commit();
} catch (Throwable e) {
if (destTransaction != null)
destTransaction.rollback();
throw e;
}
logger.info("\nData migration complete!\n");
}
private void migrateBeans(Session sourceSession, Session destSession,
ImmutableSet<Class<?>> beanClasses, ImmutableMultimap<Class<?>, Class<?>> deps)
{
if (beanClasses.isEmpty()) return;
Class<?> head = beanClasses.iterator().next();
ImmutableSet<Class<?>> tail =
Sets.difference(beanClasses, ImmutableSet.of(head)).immutableCopy();
ImmutableSet<Class<?>> childrenOfHead = getChildren(head, tail, deps);
migrateBeans(sourceSession, destSession, childrenOfHead, deps);
migrateBean(sourceSession, destSession, head);
migrateBeans(sourceSession, destSession,
Sets.difference(tail, childrenOfHead).immutableCopy(), deps);
}
private ImmutableSet<Class<?>> getChildren(Class<?> parent,
ImmutableSet<Class<?>> possibleChildren,
ImmutableMultimap<Class<?>, Class<?>> deps)
{
ImmutableSet<Class<?>> parentDeps = ImmutableSet.copyOf(deps.get(parent));
return Sets.intersection(possibleChildren, parentDeps).immutableCopy();
}
private void migrateBean(Session sourceSession, Session destSession,
Class<?> beanClass)
{
GenericDAOHibernate<?, Serializable> sourceDao =
sourceDaoFactory.get(beanClass, sourceSession);
logger.info("Migrating "+sourceDao.countAll()+" of "+beanClass);
DAOOptions options = new DAOOptions();
options.setMaxResults(copyBatchSize);
List<?> sourceBeans;
int firstResult = 0;
int sourceBeansSize;
do {
options.setFirstResult(firstResult);
sourceBeans = sourceDao.findAll(options);
sourceBeansSize = sourceBeans.size();
@SuppressWarnings("unchecked")
GenericDAOHibernate<Object, Serializable> destDao =
(GenericDAOHibernate<Object, Serializable>)
destDaoFactory.get(beanClass, destSession);
for (Object sourceBean : sourceBeans)
{
destDao.save(sourceBean);
}
firstResult += copyBatchSize;
sourceSession.clear();/* prevent memory problems */
} while (sourceBeansSize >= copyBatchSize);
}
}
स्रोत
2012-09-28 06:14:03
मैं यह कोशिश कर रहा हूं, लेकिन परिपत्र संबंधों के साथ एक समस्या में भाग गया है।डीबी बाधाओं को नष्ट करने की जांच की गई, लेकिन ऐसा करने का एक स्पष्ट तरीका नहीं मिला। अपमानजनक रिश्तों को हटाने/पुनर्निर्माण के लिए कस्टम कोड लिखना पड़ सकता है। –