title: Failed to read schema document 'http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd
body: <p>I'm writing a simple Swing app for university and using Hibernate and Oracle XE.</p>
  
  <p>I'm stuck with that error:</p>
  
  <pre><code> 29.06.2011 14:54:10 org.hibernate.cfg.annotations.Version &lt;clinit&gt;
   INFO: Hibernate Annotations 3.3.1.GA
   29.06.2011 14:54:10 org.hibernate.cfg.Environment &lt;clinit&gt;
   INFO: Hibernate 3.2.5
   29.06.2011 14:54:10 org.hibernate.cfg.Environment &lt;clinit&gt;
   INFO: hibernate.properties not found
   29.06.2011 14:54:10 org.hibernate.cfg.Environment buildBytecodeProvider
   INFO: Bytecode provider name : cglib
   29.06.2011 14:54:10 org.hibernate.cfg.Environment &lt;clinit&gt;
   INFO: using JDK 1.4 java.sql.Timestamp handling
   29.06.2011 14:54:10 org.hibernate.ejb.Version &lt;clinit&gt;
   INFO: Hibernate EntityManager 3.3.2.GA
   29.06.2011 14:54:31 org.hibernate.ejb.packaging.PersistenceXmlLoader$ErrorLogger warning
   WARNING: Warning parsing XML: XML InputStream(2) schema_reference.4: Failed to read schema document 'http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd', because 1) could not find the document; 2) the document could not be read; 3) the root element of the      document is not &lt;xsd:schema&gt;.
   29.06.2011 14:54:52 org.hibernate.ejb.packaging.PersistenceXmlLoader$ErrorLogger warning
  </code></pre>
  
  <p>my persistence.xml:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"&gt;
    &lt;persistence-unit name="airportPU"&gt;
      &lt;provider&gt;org.hibernate.ejb.HibernatePersistence&lt;/provider&gt;
      &lt;class&gt;my.airport.model.Crew&lt;/class&gt;
      &lt;class&gt;my.airport.model.Country&lt;/class&gt;
      &lt;class&gt;my.airport.model.City&lt;/class&gt;
      &lt;class&gt;my.airport.model.Plane&lt;/class&gt;
      &lt;class&gt;my.airport.model.Model&lt;/class&gt;
      &lt;class&gt;my.airport.model.Passenger&lt;/class&gt;
      &lt;class&gt;my.airport.model.Role&lt;/class&gt;
      &lt;class&gt;my.airport.model.Airport&lt;/class&gt;
      &lt;class&gt;my.airport.model.Spec&lt;/class&gt;
      &lt;class&gt;my.airport.model.AverageFlightTime&lt;/class&gt;
      &lt;class&gt;my.airport.model.CrewInTheRoleOnTheFlight&lt;/class&gt;
      &lt;class&gt;my.airport.model.Flight&lt;/class&gt;
      &lt;class&gt;my.airport.model.PassengersOnTheFlight&lt;/class&gt;
      &lt;properties&gt;     
        &lt;property name="javax.persistence.jdbc.url" value="jdbc:oracle:thin:@172.16.0.3:1521:XE"/&gt;
        &lt;property name="javax.persistence.jdbc.password" value="AIRPORT"/&gt;
        &lt;property name="javax.persistence.jdbc.driver" value="oracle.jdbc.OracleDriver"/&gt;
        &lt;property name="javax.persistence.jdbc.user" value="AIRPORT"/&gt;
      &lt;/properties&gt;
    &lt;/persistence-unit&gt;
  &lt;/persistence&gt;
  </code></pre>
  
  <p>Creating entity manager factory:</p>
  
  <pre><code>public static EntityManagerFactory emf;
  public static EntityManager em;
  static {
  try {
      emf = Persistence.createEntityManagerFactory("airportPU");
      em = emf.createEntityManager();
  } catch (Exception e) {     
      System.exit(1);
  }
  }
  </code></pre>