jsp with servlets

Posted on 2009-04-29
Medium Priority
Last Modified: 2013-11-24
i have a login,jsp and the servlet check_loginservlet checks whether the user is valid or invalid. In case of invalid login i want it to directed to login.jsp itself but with error message displayed. If i set the error message in session and do session.getAttribute("error") in the jsp it displays null there first time. So what is the way to avoid null display. Do i need to have java code here saying if it is null then do not display anything else display it.
Question by:SunScreenCert

Assisted Solution

TheVeee earned 120 total points
ID: 24262414
Just do a check if present or not in your jsp..

This one is using struts tag lib...

    <logic:present name="name">
        <bean:write name="name" property="name"/>

Author Comment

ID: 24263577
can you please give this code without using logic tags of struts because i am using jsp and servlets
LVL 27

Accepted Solution

mrcoffee365 earned 380 total points
ID: 24264041
I'll assume you're not using the built-in login functionality provided with your servlet engine, because this sounds as if you've written your own login.

You should post your code if you want help with it, but I'm going to guess that you have something like this:

<font color="red">Invalid login</font>

What you want is to wrap an if statement around it, like this:

  String errorMsg = (String) session.getAttribute("error");
  if( errorMsg != null && errorMsg.length() < 0 ) {
<font color="red">Invalid login</font>
<%  }  

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