I used Hibernate in my RCP program， the code related to the exception is following:(i use Hibernate2.1 ,Eclipse 3.2.)
package com.uxteam.reload.facestudiod;

import net.sf.hibernate.HibernateException;
import net.sf.hibernate.Session;
import net.sf.hibernate.SessionFactory;
import net.sf.hibernate.cfg.Configuration;

import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Label;
import org.eclipse.ui.part.ViewPart;

public class ViewPart1 extends ViewPart{

public ViewPart1(){
super();
}


public void createPartControl(Composite parent) {

Label label=new Label(parent,SWT.NONE);
label.setText("这是一个ViewPart测试");

try {
Configuration conf = null;
conf = new Configuration().configure();

String contenthql="select myatom.teAtomContent from edu.ustc.infosec.te.SteAtom as myatom "
+"where myatom.teAtomClass=3 and myatom.teAtomObjectId=20100000001";

SessionFactory sf=new
Configuration().configure().buildSessionFactory();
final Session session=sf.openSession();


java.util.List concentlist=session.createQuery(contenthql).list();

session.close();
System.out.println("OK");

} catch (HibernateException e) {
e.printStackTrace();
}
}

public void setFocus() {

}
}

The application can run ,but there are exceptions like this:
java.lang.NoClassDefFoundError: net/sf/hibernate/HibernateException
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Unknown Source)
at java.lang.Class.getConstructor0(Unknown Source)
at java.lang.Class.newInstance0(Unknown Source)
at java.lang.Class.newInstance(Unknown Source)
at org.eclipse.core.internal.registry.osgi.RegistryStrategyOSGI.createExecutableExtension(RegistryStrategyOSGI.java:157)
at org.eclipse.core.internal.registry.ExtensionRegistry.createExecutableExtension(ExtensionRegistry.java:759)
at org.eclipse.core.internal.registry.ConfigurationElement.createExecutableExtension(ConfigurationElement.java:243)
at org.eclipse.core.internal.registry.ConfigurationElementHandle.createExecutableExtension(ConfigurationElementHandle.java:51)
at org.eclipse.ui.internal.WorkbenchPlugin.createExtension(WorkbenchPlugin.java:234)
at org.eclipse.ui.internal.registry.ViewDescriptor.createView(ViewDescriptor.java:69)
at org.eclipse.ui.internal.ViewReference.createPartHelper(ViewReference.java:292)
at org.eclipse.ui.internal.ViewReference.createPart(ViewReference.java:197)
at org.eclipse.ui.internal.WorkbenchPartReference.getPart(WorkbenchPartReference.java:566)
at org.eclipse.ui.internal.WorkbenchPage$ActivationList.setActive(WorkbenchPage.java:3898)
at org.eclipse.ui.internal.WorkbenchPage.restoreState(WorkbenchPage.java:2922)
at org.eclipse.ui.internal.WorkbenchWindow.restoreState(WorkbenchWindow.java:1936)
at org.eclipse.ui.internal.Workbench.doRestoreState(Workbench.java:2857)
at org.eclipse.ui.internal.Workbench.restoreState(Workbench.java:1665)
at org.eclipse.ui.internal.Workbench.access$12(Workbench.java:1650)
at org.eclipse.ui.internal.Workbench$17.run(Workbench.java:1529)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:37)
at org.eclipse.ui.internal.Workbench.restoreState(Workbench.java:1473)
at org.eclipse.ui.internal.WorkbenchConfigurer.restoreState(WorkbenchConfigurer.java:183)
at org.eclipse.ui.application.WorkbenchAdvisor.openWindows(WorkbenchAdvisor.java:702)
at org.eclipse.ui.internal.Workbench.init(Workbench.java:1085)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:1847)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:419)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at com.uxteam.reload.facestudiod.intro.Application.run(Application.java:18)
at org.eclipse.core.internal.runtime.PlatformActivator$1.run(PlatformActivator.java:78)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:92)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:68)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:400)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:177)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.eclipse.core.launcher.Main.invokeFramework(Main.java:336)
at org.eclipse.core.launcher.Main.basicRun(Main.java:280)
at org.eclipse.core.launcher.Main.run(Main.java:977)
at org.eclipse.core.launcher.Main.main(Main.java:952)

Does anybody know how to solve this problem?
Thanks in advance.

Make sure you have the hibernate2.jar in the classpath of your application.

i am sure of that.