i'm running the example of the Cat included in hibernate reference, but i had problems with HibernateUtil.java, so i decided to include a small main() in HibernateUtil to quickly discover the problems. the class reads as follows, and it's simply the class suggested in the hibernate reference with a main() added that opens and closes the session:
Code:
import org.hibernate.*;
import org.hibernate.cfg.*;
import org.apache.commons.logging.*;
public class HibernateUtil {
private static Log log = LogFactory.getLog(HibernateUtil.class);
private static final SessionFactory sessionFactory;
static {
try {
// Create the SessionFactory
sessionFactory = new Configuration().configure().buildSessionFactory();
} catch (Throwable ex) {
log.error("Initial SessionFactory creation failed.", ex);
throw new ExceptionInInitializerError(ex);
}
}
public static final ThreadLocal session = new ThreadLocal();
public static Session currentSession() throws HibernateException {
Session s = (Session) session.get();
// Open a new Session, if this Thread has none yet
if (s == null) {
s = sessionFactory.openSession();
session.set(s);
}
return s;
}
public static void closeSession() throws HibernateException {
Session s = (Session) session.get();
session.set(null);
if (s != null)
s.close();
}
public static void main(String[] args) {
Session session = HibernateUtil.currentSession();
HibernateUtil.closeSession();
}
}
Hibernate version: 3.0
Mapping documents:Cat.hbm.xml, placed in the same directory as Cat.java (\jakarta-tomcat-5.0.28\webapps\quickstart\quickstart\src\net\sf\hibernate\examples\quickstart)
Code:
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping>
<class name="net.sf.hibernate.examples.quickstart.Cat" table="CAT">
<!-- A 32 hex character is our surrogate key. It's automatically
generated by Hibernate with the UUID pattern. -->
<id name="id" type="string" unsaved-value="null" >
<column name="CAT_ID" sql-type="char(32)" not-null="true"/>
<generator class="uuid.hex"/>
</id>
<!-- A cat has to have a name, but it shouldn' be too long. -->
<property name="name">
<column name="NAME" length="16" not-null="true"/>
</property>
<property name="sex"/>
<property name="weight"/>
</class>
</hibernate-mapping>
compile-single:
log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).
log4j:WARN Please initialize the log4j system properly.
java.lang.ExceptionInInitializerError
at HibernateUtil.<clinit>(HibernateUtil.java:30)
Caused by: org.hibernate.MappingException: Resource: Cat.hbm.xml not found
at org.hibernate.cfg.Configuration.addResource(Configuration.java:444)
at org.hibernate.cfg.Configuration.parseMappingElement(Configuration.java:1313)
at org.hibernate.cfg.Configuration.parseSessionFactory(Configuration.java:1285)
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1267)
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1234)
at org.hibernate.cfg.Configuration.configure(Configuration.java:1162)
at org.hibernate.cfg.Configuration.configure(Configuration.java:1148)
at HibernateUtil.<clinit>(HibernateUtil.java:27)
Name and version of the database you are using:
mysql 4.1
it seems like i have not initialized the log4j system properly, but i cannot guess why....
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