How to make servlets for openshift tomcat?

So I got all keys, tools for Eclipse, created new deafult applicaion, ok it shows somepage.

Then I change

src/main/webapp/WEB-INF/web.xml

as it is told to in readme on:

    <servlet>
    <servlet-name>work</servlet-name>
    <servlet-class>kea.webpro.WorkServlet</servlet-class>    
  </servlet>  
  <servlet-mapping>
    <servlet-name>work</servlet-name>
    <url-pattern>/work</url-pattern>
  </servlet-mapping> 

And add some java-classes in

src/main/java

And then I go here i get

java.lang.ClassNotFoundException: kea.webpro.WorkServlet at first time and next times resource not found.

I guess my custom web.xml has been succesfully read. But my java class unfortunately not. So how to make simple servlet that generating some simple html-page with hello world on openshift tomcat?

At my local tomcat everything is fine, I generate whatever i want to. though my servlet structure is much more simple.