Problem with this piece of jsp

Question

Hi,
I have a problem with this piece of code, and I dont know why is the error caused:
<% String value=(String)session.getAttribute("add");
*if (value.equals("add")) { *  %>
<th>Add quantity</th>
<% } else {  %>
<th>Modify quantity</th>
<% } %>
When I debug Apache Tomcat log gives me the NullPointerException error, in the line underlined in bold, but theorically if the sentence "if" is not true it should enter in the "else" part but it doesn`t do, and I dont have the explanation.
I would be very grateful if somebody could help to solve this problem.
Regards.
Edited by: user1577231 on 04-oct-2010 6:33

Answer 1

If you get a NullPointerException at that point, then that probably means that value is null.
The easiest way to avoid this NPE is to write "add".equals(value) instead.