import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class MyServlet extends HttpServlet {
public void doPost(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
res.setContentType("text/html");
PrintWriter out = res.getWriter();
String account = req.getParameter("account");
String password = req.getParameter("password");
String pin = req.getParameter("pin");
if (!allowUser(account, password, pin)) {
out.println("<HTML><HEAD><TITLE>Access Denied</TITLE></HEAD>");
out.println("<BODY>Your login and password are invalid.<BR>");
out.println("You may want to <A HREF=\"/login.html\">try again</A>");
out.println("</BODY></HTML>");
}
else {
out.println("<HTML><HEAD><TITLE>Access Denied</TITLE></HEAD>");
out.println("<BODY>Your login and password are valid.<BR>");
out.println("</BODY></HTML>");
HttpSession session = req.getSession();
session.setAttribute("logon.isDone", account); // just a marker object
try {
String target = (String) session.getAttribute("login.target");
if (target != null) {
res.sendRedirect(target);
return;
}
}
catch (Exception ignored) { }
//res.sendRedirect("/");
}
}
protected boolean allowUser(String account, String password, String pin) {
return true;
}
}
<HTML>
<TITLE>Login</TITLE>
<BODY>
<FORM ACTION=LoginHandler.do METHOD=POST>
<CENTER>
<TABLE BORDER=0>
<TR><TD COLSPAN=2>
<P ALIGN=CENTER>
Welcome!<br>
Please enter your Account Number,<br>
Password, and PIN to log in.
</TD></TR>
<TR><TD>
<P ALIGN=RIGHT><B>Account:</B>
</TD>
<TD>
<P><INPUT TYPE=TEXT NAME="account" VALUE="" SIZE=15>
</TD></TR>
<TR><TD>
<P ALIGN=RIGHT><B>Password:</B>
</TD>
<TD>
<P><INPUT TYPE=PASSWORD NAME="password" VALUE="" SIZE=15>
</TD></TR>
<TR><TD>
<P ALIGN=RIGHT><B>PIN:</B>
</TD>
<TD>
<P><INPUT TYPE=PASSWORD NAME="pin" VALUE="" SIZE=15>
</TD></TR>
<TR><TD COLSPAN=2>
<CENTER>
<INPUT TYPE=SUBMIT VALUE=" OK ">
</CENTER>
</TD></TR>
</TABLE>
</FORM>
</BODY></HTML>
<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE web-app
PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd">
<web-app>
<servlet><servlet-name>MyServletName</servlet-name>
<servlet-class>MyServlet</servlet-class>
</servlet>
<servlet-mapping><servlet-name>MyServletName</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
</web-app>
Download: ServletLogin.zip( 1,067 k)