Write a servlet to display request header information?

Answer 1

Retrieving HTTP Request Header Information

The Http Request header is the area where all the details of the request are bundled. This is where the browser specifies the file wanted, date, image file support, and a lot more. Let us take a look at a sample Servlet that is going to read through the Http Request Header.

Servlet code:

import java.io.*;

import java.text.*;

import java.util.*;

import javax.servlet.*;

import javax.servlet.http.*;

/**

* Displaying request headers

*

* @author Anand V

*/

public class ReadHttpRequestHeaderServlet extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)

throws IOException, ServletException

{

response.setContentType("text/HTML");

PrintWriter out = response.getWriter();

out.println("< HTML >");

out.println("< head >");

String title = "Read Request Header Example";

out.println("< title >" + title + "");

out.println("< / head >");

out.println("< body >");

out.println("< h3 >" + title + "< / h3 >");

out.println("< table >");

Enumeration e = request.getHeaderNames();

while (e.hasMoreElements())

{

String headerName = (String)e.nextElement();

String headerValue = request.getHeader(headerName);

out.println("< tr >< td bgcolor="#CCCCCC" > " + headerName);

out.println("< / td >< td > " + headerValue + " < / td > < / tr >");

}

out.println("< / table >");

out.println("< / body >");

out.println("< / HTML >");

}

}

Answer 2

You can create a servlet that overrides the doGet method to access the request headers using the HttpServletRequest object. You can then iterate through the headers and display them as needed. Be sure to set the appropriate content type before writing the response to the HttpServletResponse object.