Servlet Login : Authentication « Servlet

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Java Tutorial » Servlet » Authentication

25. 22. 3. Servlet Login


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)

25. 22. Authentication
	25. 22. 1.	Simple Servlet Example using the getRemoteUser() method.
	25. 22. 2.	Get Auth Type from Servlet Request
	25. 22. 3.	Servlet Login
	25. 22. 4.	A password protected servlet
	25. 22. 5.	Servlet with bouncy castle security package

Servlet Login : Authentication « Servlet « Java Tutorial