### Source Code for RequestHeader Example

    import java.io.*;
    import java.util.*;
    import jakarta.servlet.*;
    import jakarta.servlet.http.*;

    public class RequestHeaderExample extends HttpServlet {

        public void doGet(HttpServletRequest request, HttpServletResponse response)
        throws IOException, ServletException
        {
            response.setContentType("text/html");
            PrintWriter out = response.getWriter();
            Enumeration e = request.getHeaderNames();
            while (e.hasMoreElements()) {
                String name = (String)e.nextElement();
                String value = request.getHeader(name);
                out.println(name + " = " + value);
            }
        }
    }