Hibernate+GWT problem related to slf4j

[Ahmet Terzioglu]

Hello everyone,

I am trying to run a very simple application using GWT (1.6.4) and Hibernate (3.3.1) together.
I keep getting this error :

Initial SessionFactory creation failed.
java.lang.NoClassDefFoundError: org/slf4j/LoggerFactory

I get the exception at this point in my simple HibernateUtil after an RPC call is made to the server and the server tries to create a SessionFactory to handle the transaction:
I get the exception at this line ---> Configuration config =new Configuration().configure();

public class HibernateUtil { 
  private static final SessionFactory sessionFactory; 

  static { 
    try { 
    	Configuration config =new Configuration().configure();
    	sessionFactory = config.buildSessionFactory(); 
    } catch (Throwable ex) { 
      System.err.println(
        "Initial SessionFactory creation failed. \n" + ex); 

      throw new ExceptionInInitializerError(ex); 
    } 
  }

I use the following xml:

<hibernate-configuration>
<session-factory>
      <property name="connection.url">jdbc:mysql://localhost/contactbook</property>
      <property name="connection.username">root</property>
      <property name="connection.password">funfun</property>
      <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
      <property name="dialect">org.hibernate.dialect.MySQLDialect</property>  
      <property name="transaction.factory_class">org.hibernate.transaction.JDBCTransactionFactory</property>
      <property name="current_session_context_class">thread</property>
      <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
      <!-- Mapping files -->
      <mapping resource="com/mycompany/project/client/Contact.hbm.xml"/>
</session-factory>
</hibernate-configuration>

YES, I have both the slf4j api and the slf4j-simple jar in my classpath. (tried NOP and slf4j-log4j instead of simple as well)
YES, I have tried both slf4j 1.5.6 and 1.5.2

Even though the LoggerFactory is right there in the api I get the ClassDefNotFound error.

I am guessing there is a clash with some other library...
My classpath contains :
gwt-user.jar
c3p0-0.8.5.jar
commons-collections-3.1.jar
dom4j-1.6.1.jar
ejb3-persistence.jar
hibernate3.jar
hibernate-annotations.jar
hibernate-commons-annotations.jar
hibernate-entitymanager.jar
mysql-connector-java-5.1.6-bin.jar
log4j.jar
slf4j-api-1.5.2.jar
slf4j-simple-1.5.2.jar
jta-1.1.jar
antlr-2.7.6.jar
javassist-3.4.GA.jar

[Cameron Wallace McKenzie]

If you try to do something simple like:

import  org.slf4j.LoggerFactory;     

in your code, does it compile? If it doesn't, then you don't have the slf4j on your design-time classpath either.

Try it, and see if you've even got access at design time.

-Cameron McKenzie

[Cameron Wallace McKenzie]

Any chance you're actually using a higher version of Hibernate? Annotations?

-Cameron McKenzie

[Chris Brooks]

I have the same problem, and am using the latest versions.

Windows XP
Eclipse: 3.4.1 Build: M20080911-1700
Google Plugin for Eclipse 3.4
Google Web Toolkit SDK 1.6.4
GWT 1.6.4
Hibernate Core 3.3.1
Hibernate Annotations 3.4.0
SLF4J 1.5.6

Any thoughts?

[Panu Tang]

I was having this problem too. To solve this problem, just copy slf4f and slf4j-log4j (if you use log4j) jar file to war\WEB-INF\lib.