import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
/**
* Hello World! servlet with visitor counter.
* Multiple visits within a short time span by
* a single user are counted as a single visit.
*/
public class VisitorCounter extends HttpServlet
{
// Number of visitors to the servlet since
// the program (web server) started
private int visits=0;
/**
* Respond to any HTTP GET request with an
* HTML Hello World! page with visitor counter.
*/
public void doGet (HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException
{
// Set the HTTP content type in response header
response.setContentType("text/html; charset=\"UTF-8\"");
// Obtain a PrintWriter object for creating the body
// of the response
PrintWriter servletOut = response.getWriter();
// Determine whether or not this is the first visit
// by this user, and update visit count if this is
// the first visit
HttpSession session = request.getSession();
if (session.isNew()) {
visits++;
}
// Create the body of the response, including visit count
servletOut.println(
" \n" +
" \n" +
" \n" +
" \n" +
" VisitorCounter.java \n" +
" \n" +
" \n" +
" \n" +
" \n" +
" Hello World! \n" +
"
\n" +
" \n" +
" This page has been viewed by \n" +
visits +
" visitors since the most recent server restart. \n" +
"
\n" +
" \n" +
" ");
servletOut.close();
}
}