Javax Servlet Http Java by API

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class AuthenticationSnoop extends HttpServlet {
  public void doGet(HttpServletRequest req, HttpServletResponse res) throws ServletException,
      IOException {
    res.setContentType("text/html");
    PrintWriter out = res.getWriter();
    out.println("");
    out.println("

This is a password protected resource

");
    out.println("
");
    out.println("User Name: " + req.getRemoteUser());
    String name = (req.getUserPrincipal() == null) ? null : req.getUserPrincipal().getName();
    out.println("Principal Name: " + name);
    out.println("Authentication Type: " + req.getAuthType());
    out.println("Is a Manager: " + req.isUserInRole("manager"));
    out.println("
");
    out.println("");
  }
}