How do I check that a session object contains a particular key/value entry

Question

I want to check if a certain key/value pair has been set.

How do I check if a an entry with key named "keyName" exists. Sample code or a pointer to an example would be appreciated.

Answer 1

Heres a simple introductory tutorial to JSP Sessions

In essence you should just need to check that session.getAttribute("keyName") is not null.

Answer 2

You can set/get attributes (key/value) in a HttpSession object. An example: http://www.exampledepot.com/egs/javax.servlet/State.html

Answer 3

If you want to differ between "not set" and null, step through session.getAttributeNames() and search your key name.