I am ready to scream. I have been trying (for days) to set up Hibernate for a simple application in IntelliJ against an Oracle database. Every google search turns up useless configurations for a server that I don't need.

The current error that I have is below. I can't find anything that tells me how to get rid of the logger error and the Persistence error is a real treat as well. I need to start from scratch with a step-by-step and line-by-line set of instructions. Can anyone provide a list of the absolute basics to set up a database connection?

log4j:WARN No appenders could be found for logger (org.hibernate.cfg.annotations.Version).
log4j:WARN Please initialize the log4j system properly.
javax.persistence.PersistenceException: [PersistenceUnit: ManagerUnit] Unable to configure EntityManagerFactory
at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:265)
at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:125)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:51)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:33)
at astronomy.test.HibernateOracleTest.initEntityManager(HibernateOracleTest.java:67)
at astronomy.test.HibernateOracleTest.<clinit>(HibernateOracleTest.java:37)
Caused by: org.hibernate.AnnotationException: java.lang.NoSuchMethodException: org.hibernate.validator.ClassValidator.<init>(java.lang.Class, java.util.ResourceBundle, org.hibernate.validator.MessageInterpolator, java.util.Map, org.hibernate.annotations.common.reflection.ReflectionManager)
at org.hibernate.cfg.AnnotationConfiguration.secondPassCompile(AnnotationConfiguration.java:374)
at org.hibernate.cfg.Configuration.buildMappings(Configuration.java:1162)
at org.hibernate.ejb.Ejb3Configuration.buildMappings(Ejb3Configuration.java:1226)
at org.hibernate.ejb.EventListenerConfigurator.configure(EventListenerConfigurator.java:173)
at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:854)
at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:191)
at org.hibernate.ejb.Ejb3Configuration.configure(Ejb3Configuration.java:253)
... 5 more
Caused by: java.lang.NoSuchMethodException: org.hibernate.validator.ClassValidator.<init>(java.lang.Class, java.util.ResourceBundle, org.hibernate.validator.MessageInterpolator, java.util.Map, org.hibernate.annotations.common.reflection.ReflectionManager)
at java.lang.Class.getConstructor0(Unknown Source)
at java.lang.Class.getDeclaredConstructor(Unknown Source)
at org.hibernate.cfg.AnnotationConfiguration.secondPassCompile(AnnotationConfiguration.java:362)
... 11 more
Nov 29, 2009 9:48:31 AM astronomy.test.HibernateOracleTest initEntityManager
INFO: Exception during JPA EntityManager instanciation.

The log4j thing doesn't have anything to do with hibernate, you'll need to look at the log4j doco to figure out what you're doing wrong. Try setting the log4j.debug property (or whatever it's called); that will pump out some debug info to stdout so you can try to diagnose the issue.

The persistence error is a bit weird - once you've got your log configuration issues sorted out, it might tell you a bit more about what's going on. If not, try to reduce your problem to a simple test case and post your mappings to see if people can help.

I finally did get it working by modifying an old tutorial that I had. The approach that I had to use was slightly different but, I still have no idea why the other one didn't work. Even the log error went away.