Problem with import RCP plugin to Vaadin

Hi! I have problem with to import outside class to Vaadin.
This is stacktrace in Chrome:

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: java.lang.ExceptionInInitializerError
	com.vaadin.terminal.gwt.server.AbstractApplicationServlet.handleServiceException(AbstractApplicationServlet.java:1004)
	com.vaadin.terminal.gwt.server.AbstractApplicationServlet.service(AbstractApplicationServlet.java:548)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
root cause

java.lang.ExceptionInInitializerError
	com.lp.angel.utils.HibernateUtil.initSession(HibernateUtil.java:90)
	com.lp.angel.AngelApplication.init(AngelApplication.java:23)
	com.vaadin.Application.start(Application.java:554)
	com.vaadin.terminal.gwt.server.AbstractApplicationServlet.startApplication(AbstractApplicationServlet.java:1213)
	com.vaadin.terminal.gwt.server.AbstractApplicationServlet.service(AbstractApplicationServlet.java:484)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
root cause

java.lang.NoClassDefFoundError: com/lp/library/utils/string/Strings
	com.lp.angel.dbutils.DbConfig.createUrl(DbConfig.java:49)
	com.lp.angel.dbutils.DbConfig.<init>(DbConfig.java:37)
	com.lp.angel.dbutils.DbConfig.<clinit>(DbConfig.java:25)
	com.lp.angel.utils.HibernateUtil.initSession(HibernateUtil.java:47)
	com.lp.angel.AngelApplication.init(AngelApplication.java:23)
	com.vaadin.Application.start(Application.java:554)
	com.vaadin.terminal.gwt.server.AbstractApplicationServlet.startApplication(AbstractApplicationServlet.java:1213)
	com.vaadin.terminal.gwt.server.AbstractApplicationServlet.service(AbstractApplicationServlet.java:484)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
root cause

java.lang.ClassNotFoundException: com.lp.library.utils.string.Strings
	org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1676)
	org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1521)
	com.lp.angel.dbutils.DbConfig.createUrl(DbConfig.java:49)
	com.lp.angel.dbutils.DbConfig.<init>(DbConfig.java:37)
	com.lp.angel.dbutils.DbConfig.<clinit>(DbConfig.java:25)
	com.lp.angel.utils.HibernateUtil.initSession(HibernateUtil.java:47)
	com.lp.angel.AngelApplication.init(AngelApplication.java:23)
	com.vaadin.Application.start(Application.java:554)
	com.vaadin.terminal.gwt.server.AbstractApplicationServlet.startApplication(AbstractApplicationServlet.java:1213)
	com.vaadin.terminal.gwt.server.AbstractApplicationServlet.service(AbstractApplicationServlet.java:484)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:722)

And Console stacktrace:

=================================================================
Vaadin is running in DEBUG MODE.
Add productionMode=true to web.xml to disable debug features.
To show debug window, add ?debug to your application URL.
=================================================================
1 ["http-bio-8080"-exec-9] INFO org.hibernate.cfg.annotations.Version - Hibernate Annotations 3.4.0.GA
187 ["http-bio-8080"-exec-9] INFO org.hibernate.cfg.Environment - Hibernate 3.3.0.SP1
202 ["http-bio-8080"-exec-9] INFO org.hibernate.cfg.Environment - hibernate.properties not found
229 ["http-bio-8080"-exec-9] INFO org.hibernate.cfg.Environment - Bytecode provider name : javassist
232 ["http-bio-8080"-exec-9] INFO org.hibernate.cfg.Environment - using JDK 1.4 java.sql.Timestamp handling
901 ["http-bio-8080"-exec-9] INFO org.hibernate.annotations.common.Version - Hibernate Commons Annotations 3.1.0.GA
Initial SessionFactory creation failed.java.lang.NoClassDefFoundError: com/lp/library/utils/string/Strings
2012-05-19 15:00:33 org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [Angel Application] in context with path [/com.lp.angel] threw exception [java.lang.ExceptionInInitializerError] with root cause
java.lang.ClassNotFoundException: com.lp.library.utils.string.Strings
	at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1676)
	at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1521)
	at com.lp.angel.dbutils.DbConfig.createUrl(DbConfig.java:49)
	at com.lp.angel.dbutils.DbConfig.<init>(DbConfig.java:37)
	at com.lp.angel.dbutils.DbConfig.<clinit>(DbConfig.java:25)
	at com.lp.angel.utils.HibernateUtil.initSession(HibernateUtil.java:47)
	at com.lp.angel.AngelApplication.init(AngelApplication.java:23)
	at com.vaadin.Application.start(Application.java:554)
	at com.vaadin.terminal.gwt.server.AbstractApplicationServlet.startApplication(AbstractApplicationServlet.java:1213)
	at com.vaadin.terminal.gwt.server.AbstractApplicationServlet.service(AbstractApplicationServlet.java:484)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:562)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:395)
	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:250)
	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:188)
	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:166)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:302)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at java.lang.Thread.run(Unknown Source)