AB Infinity feb 2014 | Page 6

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5.2

A Servlet That Shows the CGI Variables

SERVER_PROTOCOL
The SERVER_PROTOCOL variable indicates the protocol name and version 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
import
import
import

java.io.*;
javax.servlet.*;
javax.servlet.http.*;
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.

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