NoClassDefFoundError: Could not initialize class [ClassName]

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Java

Hi Guys

lil help what am i missing here? Class is available at compiletime but not available on runtime.

Here's the helpre class below

public class Helper {

	private static final SessionFactory sessionFactory = buildSessionFactory();

	private static SessionFactory buildSessionFactory() 
	{
		try
		{       //Problem is here complaining 
			return new Configuration().configure().buildSessionFactory();
		}
		catch(Throwable ex)
		{
			throw new ExceptionInInitializerError(ex);
		}
	}
	
	public static SessionFactory getSessionFactory()
	{
		return sessionFactory;
	}
	public static void closeSessionFactory()
	{
		getSessionFactory().close();
	}
	
}

public List<User> userList() {
        session = (Session)Helper.getSessionFactory().openSession();
        session.beginTransaction();

        Query query = session.getNamedQuery("Users_byList");
        List<User> user = query.list();
        session.close();
        return user;
    }

When I look at the detail message i get: "Errors in named queries: Users_byList"
Here is my user

@Entity
@NamedQueries
({
		@NamedQuery(name="Users_byList",query="from tbl_user"),
	
})
@Table(name="tbl_user")
@XmlRootElement
public class User implements Serializable{
	
	
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	
	@Id
	@GeneratedValue(strategy=GenerationType.AUTO)
	  @Column(name="userID", precision=0)
	private Long userID;
	
	@Column(name = "name")
	private String name;
	
	@Column(name="surname")
	private String surname;
	
	@Column(name="email")
	private String email;
	
	@Column(name="password")
	private String password;
	
	
	@OneToMany(targetEntity=Payment.class,
			mappedBy="user",
			cascade= CascadeType.ALL,
			fetch=FetchType.LAZY)
	private List<Payment> payment;

Nov 10, 2014 12:57:51 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [Jersey] in context with path [/Payments] threw exception [java.lang.NoClassDefFoundError: Could not initialize class com.utility.Helper] with root cause
java.lang.NoClassDefFoundError: Could not initialize class com.utility.Helper
	at com.pay.dao.impl.UserDaoImpl.userList(UserDaoImpl.java:48)
	at com.pay.controller.UserController.userList(UserController.java:32)
	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 com.sun.jersey.spi.container.JavaMethodInvokerFactory$1.invoke(JavaMethodInvokerFactory.java:60)
	at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$TypeOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:185)
	at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:75)
	at com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:288)
	at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
	at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:108)
	at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
	at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:84)
	at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1469)
	at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1400)
	at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1349)
	at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1339)
	at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:416)
	at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:537)
	at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:708)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:314)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Unknown Source)

Nov 10, 2014 12:59:01 PM com.sun.jersey.spi.container.ContainerResponse mapMappableContainerException
SEVERE: The exception contained within MappableContainerException could not be mapped to a response, re-throwing to the HTTP container
java.lang.NoClassDefFoundError: Could not initialize class com.utility.Helper
	at com.pay.dao.impl.UserDaoImpl.userList(UserDaoImpl.java:48)
	at com.pay.controller.UserController.userList(UserController.java:32)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)