📄 repeatvisitor.java
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package coreservlets;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
/** Servlet that says "Welcome aboard" to first-time
* visitors and "Welcome back" to repeat visitors.
* Also see RepeatVisitor2 for variation that uses
* cookie utilities from later in this chapter.
* <P>
* Taken from Core Servlets and JavaServer Pages 2nd Edition
* from Prentice Hall and Sun Microsystems Press,
* http://www.coreservlets.com/.
* © 2003 Marty Hall; may be freely used or adapted.
*/
public class RepeatVisitor extends HttpServlet {
public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
boolean newbie = true;
Cookie[] cookies = request.getCookies();
if (cookies != null) {
for(int i=0; i<cookies.length; i++) {
Cookie c = cookies[i];
if ((c.getName().equals("repeatVisitor")) &&
// Could omit test and treat cookie name as a flag
(c.getValue().equals("yes"))) {
newbie = false;
break;
}
}
}
String title;
if (newbie) {
Cookie returnVisitorCookie =
new Cookie("repeatVisitor", "yes");
returnVisitorCookie.setMaxAge(60*60*24*365); // 1 year
response.addCookie(returnVisitorCookie);
title = "Welcome Aboard";
} else {
title = "Welcome Back";
}
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String docType =
"<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.0 " +
"Transitional//EN\">\n";
out.println(docType +
"<HTML>\n" +
"<HEAD><TITLE>" + title + "</TITLE></HEAD>\n" +
"<BODY BGCOLOR=\"#FDF5E6\">\n" +
"<H1 ALIGN=\"CENTER\">" + title + "</H1>\n" +
"</BODY></HTML>");
}
}
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