HTTP request Doesnt work

Hello everyone,

Since couple of days, I’ve been trying to handle with user authentication using spnego and kerberos in my application written in java using Vaadin. I would like to ask for difference between vaadinRequest.getRemoteUser() and jsp request.getRemoteUser()?

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
    <title>Hello SPNEGO Example</title>

Hello1 <%= request.getRemoteUser() %><br>
Hello2 <%= request.getRemoteHost() %>
protected void init(VaadinRequest vaadinRequest) {

@WebServlet(urlPatterns = "/*", name = "MyUIServlet", asyncSupported = true)
@VaadinServletConfiguration(ui = MyUI.class, productionMode = false)
public static class MyUIServlet extends VaadinServlet {

	private static final long serialVersionUID = 1L;

What should I do, to rather understand the logical aspects of using authentication in Vaadin?

Of course I am using same Tomcat as an app container in both cases.

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