Debugging JSPs

Update 4 Nov 2009
Update 8 Nov 2012

It turns out to be surprisingly difficult to debug JSPs. The error messages are usually very cryptic, and once your JSP has been translated to Java and compiled, the actual problem seems to have very little to do with the original JSP. There is a good reason for that: The program that is executing is quite different from the JSP!

Here are a few hints that will help you debug your JSPs.