XSD « Schema « JPA Q&A

1. Failed to read schema document 'http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd    stackoverflow.com

I'm writing a simple Swing app for university and using Hibernate and Oracle XE. I'm stuck with that error:

 29.06.2011 14:54:10 org.hibernate.cfg.annotations.Version <clinit>
 INFO: Hibernate Annotations 3.3.1.GA
 29.06.2011 14:54:10 org.hibernate.cfg.Environment <clinit>
 INFO: ...

2. Failed to read schema document persistence_2_0.xsd    forum.hibernate.org

I receive a warning message when attempting to load entity manager. WARN : org.hibernate.ejb.packaging.PersistenceXmlLoader - Warning parsing XML: XML InputStream(4) schema_reference.4: Failed to read schema document 'http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the document is not . My persistence.xml is as below. I browsed through net but ...