org.hibernate.HibernateException: Hibernate Dialect must be explicitly set for database: DB2
   at org.hibernate.dialect.DialectFactory.determineDialect(DialectFactory.java:62)
   at org.hibernate.dialect.DialectFactory.buildDialect(DialectFactory.java:39)
   at org.hibernate.cfg.SettingsFactory.determineDialect(SettingsFactory.java:426)
   at org.hibernate.cfg.SettingsFactory.buildSettings(SettingsFactory.java:128)
   at org.hibernate.cfg.Configuration.buildSettings(Configuration.java:2005)
   at org.hibernate.cfg.JDBCMetaDataConfiguration.readFromJDBC(JDBCMetaDataConfiguration.java:40)
   at org.netbeans.modules.hibernate.wizards.HibernateCodeGenWizard.generateClasses(HibernateCodeGenWizard.java:328)
   at org.netbeans.modules.hibernate.wizards.HibernateCodeGenWizard.instantiate(HibernateCodeGenWizard.java:419)
   at org.openide.loaders.TemplateWizard$InstantiatingIteratorBridge.instantiate(TemplateWizard.java:1019)
   at org.openide.loaders.TemplateWizard.handleInstantiate(TemplateWizard.java:591)
   at org.openide.loaders.TemplateWizard.instantiateNewObjects(TemplateWizard.java:412)
   at org.openide.loaders.TemplateWizardIterImpl.instantiate(TemplateWizardIterImpl.java:256)
   at org.openide.loaders.TemplateWizardIteratorWrapper.instantiate(TemplateWizardIteratorWrapper.java:168)
   at org.openide.WizardDescriptor.callInstantiateOpen(WizardDescriptor.java:1548)
   at org.openide.WizardDescriptor.callInstantiate(WizardDescriptor.java:1505)
   at org.openide.WizardDescriptor.access$1700(WizardDescriptor.java:137)
   at org.openide.WizardDescriptor$Listener$2$1.run(WizardDescriptor.java:2076)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1424)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1968)