title: Unable to open jar file in eclipse
body: <p>I am unable to open jar files in eclipse. For example:</p>
  
  <p><strong>public class HttpSessionAndContextExa extends HttpServlet</strong></p>
  
  <p>if I want to see HttpServlet class it show me following error:</p>
  
  <p>javax.servlet.http.HttpServlet<br>
  Note: This element neither has attached source nor attached Javadoc and hence no Javadoc   could be found. Please help.</p>