User authentication on LDAP with JSP/Servlet

Question

Please help! What I need is a small Java Servlet or JSP that I can run from a web server that will allow users type in their username and password. The JSP will then authenticate the user (by trying to log onto the LDAP server as that user) and if successful will offer them the chance to change their password. If they do it will then communicate with the LDAP server as that user and change their password.
The LDAP server I am using is the Sun(TM) ONE 5.1 directory server.

Answer 1

You can use jsp's and servlets.
Have a .jsp (i.e. login.jsp) that has 2 fields username / password and a submit button i.e.
<form method="post" action="/servlet/LoginServlet">
<input type="text" size="15" name="username" value="">
<input type="password" size="15" name="password" value="">
<input type="submit" name="Submit" value="Authenticate">
</form>In your servlet (i.e. LoginServlet) is where you retrieve the username / password by doing something like:
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  String username = request.getParameter("username");
  String password = request.getParameter("password"); 
}You would now do your LDAP authentication. see http://java.sun.com/products/jndi/tutorial/ldap/security/ldap.html
Depending on whether the authentication was successful or not you would redirect the user to an error page or to the next .jsp (i.e changePassword.jsp) where they can change their password.