title: java.lang.ClassNotFoundException: org.hibernate.HibernateException
body: <p>Solution for this ...</p>
  
  <blockquote>
    <p>java.lang.ClassNotFoundException: org.hibernate.HibernateException    at
    org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1680)
      at
    org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526)
      at com.example.servlet.Operation.doPost(Operation.java:52)  at
    javax.servlet.http.HttpServlet.service(HttpServlet.java:637)  at
    javax.servlet.http.HttpServlet.service(HttpServlet.java:717)  at
    org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
      at
    org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
      at
    org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
      at
    org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
      at
    org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
      at
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
      at
    org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
      at
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
      at
    org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
      at
    org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
      at
    org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
      at java.lang.Thread.run(Unknown Source)</p>
  </blockquote>
  
  <p>please give me solution for this error</p>