Prentice Hall and Sun Microsystems. Personal use only; do not redistribute.

5.2 A Servlet That Shows the CGI Variables

119

SERVER_PROTOCOL

The 

SERVER_PROTOCOL

 variable indicates the protocol name and ver 

sion used in the request line (e.g., 

HTTP/1.0 

or 

HTTP/1.1

). Access it by 

calling 

request.getProtocol()

.

SERVER_SOFTWARE

This variable gives identifying information about the Web server. Access 

it by means of 

getServletContext().getServerInfo()

.

5.2 A Servlet That Shows the CGI 

Variables

Listing 5.1 presents a servlet that creates a table showing the values of all the

CGI variables other than 

HTTP_XXX_YYY

, which are just the HTTP request

headers described in Chapter 4. Figure 5 1 shows the result for a typical

request. 

Listing 5.1 ShowCGIVariables.java 

package coreservlets;

import java.io.*;

import javax.servlet.*;

import javax.servlet.http.*;

import java.util.*;

/** Creates a table showing the current value of each

 *  of the standard CGI variables.

 */

public class ShowCGIVariables extends HttpServlet {

  public void doGet(HttpServletRequest request,

                    HttpServletResponse response)

      throws ServletException, IOException {

    response.setContentType("text/html");

    PrintWriter out = response.getWriter();

    String[][] variables =

      { { "AUTH_TYPE", request.getAuthType() },

        { "CONTENT_LENGTH",

          String.valueOf(request.getContentLength()) },

        { "CONTENT_TYPE", request.getContentType() },

Second edition of this book: www.coreservlets.com; Sequel: www.moreservlets.com.

Servlet and JSP training courses by book's author: courses.coreservlets.com.