Exception of "Initial SessionFactory creation failed..."

hibernate v3.2
Mysql v5.0
Eclispe v3.2

when I run an application based on the demo of "Hibernate 3.2", I met
some exceptions below:

09:46:49,818 INFO Environment:500 - Hibernate 3.2.0
Initial SessionFactory creation
failed.java.lang.ExceptionInInitializerError
Exception in thread "main" java.lang.ExceptionInInitializerError
at util.HibernateUtil.<clinit>(HibernateUtil.java:18)
at messages.MessageManager.listMessages(MessageManager.java:48)
at messages.MessageManager.main(MessageManager.java:16)
Caused by: java.lang.ExceptionInInitializerError
at org.hibernate.cfg.Configuration.reset(Configuration.java:168)
at org.hibernate.cfg.Configuration.<init>(Configuration.java:187)
at org.hibernate.cfg.Configuration.<init>(Configuration.java:191)
at util.HibernateUtil.<clinit>(HibernateUtil.java:13)
.... 2 more
Caused by: java.lang.NullPointerException
at
org.hibernate.util.ConfigHelper.getResourceAsStream(ConfigHelper.java:144)
at org.hibernate.cfg.Environment.<clinit>(Environment.java:515)
.... 6 more

these are the codes:
1. sql script
drop database if exists SAMPLEDB;
create database SAMPLEDB;
use SAMPLEDB;

create table messages (
  Message_ID bigint not null primary key,
  Message_TITLE varchar(15) not null,
  Message_CONTENT varchar(128) not null,
  Message_DATE timestamp
);

2. src/hibernate.cfg.xml
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"

"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<hibernate-configuration>

<session-factory>

   <!-- Database connection settings -->
   <property
name="connection.driver_class">com.mysql.jdbc.Driver</property>
   <property
name="connection.url">jdbc:mysql://localhost:3306/sampledb</property>
   <property name="connection.username">root</property>
   <property name="connection.password">123456</property>

   <!-- JDBC connection pool (use the built-in) -->
   <property name="connection.pool_size">1</property>

   <!-- SQL dialect -->
   <property
name="dialect">org.hibernate.dialect.MySQLDialect</property>

   <!-- Enable Hibernate's automatic session context management -->
   <property name="current_session_context_class">thread</property>

   <!-- Disable the second-level cache -->
   <property name="cache.provider_class">
      org.hibernate.cache.NoCacheProvider
   </property>

   <!-- Echo all executed SQL to stdout -->
   <property name="show_sql">true</property>

   <!-- Drop and re-create the database schema on startup -->
   <property name="hbm2ddl.auto">create</property>

   <mapping resource="messages/Message.hbm.xml" />

</session-factory>

</hibernate-configuration>

3. src/log4j.properties
### direct log messages to stdout ###
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p
%c{1}:%L - %m%n

### direct messages to file hibernate.log ###
#log4j.appender.file=org.apache.log4j.FileAppender
#log4j.appender.file.File=hibernate.log
#log4j.appender.file.layout=org.apache.log4j.PatternLayout
#log4j.appender.file.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L
- %m%n

### set log levels - for more verbose logging change 'info' to 'debug'
###

log4j.rootLogger=warn, stdout

log4j.logger.org.hibernate=info
#log4j.logger.org.hibernate=debug

### log HQL query parser activity
#log4j.logger.org.hibernate.hql.ast.AST=debug

### log just the SQL
#log4j.logger.org.hibernate.SQL=debug

### log JDBC bind parameters ###
log4j.logger.org.hibernate.type=info
#log4j.logger.org.hibernate.type=debug

### log schema export/update ###
log4j.logger.org.hibernate.tool.hbm2ddl=debug

### log HQL parse trees
#log4j.logger.org.hibernate.hql=debug

### log cache activity ###
#log4j.logger.org.hibernate.cache=debug

### log transaction activity
#log4j.logger.org.hibernate.transaction=debug

### log JDBC resource acquisition
#log4j.logger.org.hibernate.jdbc=debug

### enable the following line if you want to track down connection ###
### leakages when using DriverManagerConnectionProvider ###
#log4j.logger.org.hibernate.connection.DriverManagerConnectionProvider=trace

4. src/util/HibernateUtil.java
package util;

import org.hibernate.*;
import org.hibernate.cfg.*;

public class HibernateUtil {

   private static final SessionFactory sessionFactory;

   static {
      try {
         // Create the SessionFactory from hibernate.cfg.xml
         sessionFactory = new Configuration().configure()
               .buildSessionFactory();
      } catch (Throwable ex) {
         // Make sure you log the exception, as it might be swallowed
         System.err.println("Initial SessionFactory creation failed." +
ex);
         throw new ExceptionInInitializerError(ex);
      }
   }

   public static SessionFactory getSessionFactory() {
      return sessionFactory;
   }

}

5. src/messages/Message.java
package messages;

import java.util.*;

public class Message {
   private Long id;

   private String title;

   private String content;

   private Date date;

   public Message() {
   }

   public Long getId() {
      return id;
   }

   private void setId(Long id) {
      this.id = id;
   }

   public Date getDate() {
      return date;
   }

   public void setDate(Date date) {
      this.date = date;
   }

   public String getTitle() {
      return title;
   }

   public void setTitle(String title) {
      this.title = title;
   }

   public String getContent() {
      return content;
   }

   public void setContent(String content) {
      this.content = content;
   }
}

6. src/messages/Message.hbm.xml
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping>

   <class name="messages.Message" table="messages">
      <id name="id" type="long" column="message_ID">
         <generator class="native" />
      </id>
      <property name="date" type="timestamp" column="message_DATE" />
      <property name="title" type="string" column="message_TITLE" />
      <property name="content" type="string" column="message_CONTENT"
/>
   </class>

</hibernate-mapping>

7. src/messages/MessageManager.java
package messages;

import org.hibernate.*;
import java.util.*;

import util.HibernateUtil;

public class MessageManager {

   public static void main(String[] args) {
      MessageManager mgr = new MessageManager();

      if (args[0].equals("store")) {
         mgr.createAndStoreMessage("My Message", "My Content", new
Date());
      } else if (args[0].equals("list")) {
         List messages = mgr.listMessages();
         for (int i = 0; i < messages.size(); i++) {
            Message theMessage = (Message) messages.get(i);
            System.out.println("Message: " + theMessage.getTitle()
                  + " Content: " + theMessage.getContent() + " Time: "
                  + theMessage.getDate());
         }
      }

      HibernateUtil.getSessionFactory().close();
   }

   private Long createAndStoreMessage(String title, String content,
         Date theDate) {

      Session session =
HibernateUtil.getSessionFactory().getCurrentSession();
      session.beginTransaction();

      Message theMessage = new Message();
      theMessage.setTitle(title);
      theMessage.setContent(content);
      theMessage.setDate(theDate);

      session.save(theMessage);

      session.getTransaction().commit();

      return theMessage.getId();
   }

   private List listMessages() {

      Session session =
HibernateUtil.getSessionFactory().getCurrentSession();
      session.beginTransaction();

      List result = session.createQuery("from Message").list();

      session.getTransaction().commit();

      return result;
   }

}

I had added all .jar files of Hibernate/lib directory to the classpath.
it is so strange:
the codes run ok on NetBeans 5.5, but can't work on Eclipse 3.2.
who can tell me why?

thanks a lot!

Best Regards,

Thomas

ps: My MSN ID: qixiangnj@gmail.com.