Question

I am using ant to build a jar of my project in eclipse. I deploy that jar on tomcat. But whenever an exception happen in my code (which is inside jar), the error stack trace comes but the line number does not come — instead it says unknown source.

How can I get the line numbers in error stack trace?

Answer 1

You need to compile your jar with debug information. Specifically, you need to find the javac task that compiles the classes that you later jar and add a debug="on" attribute. Example:

<javac srcdir="${src}"
     destdir="${build}"
     classpath="xyz.jar"
     debug="on"
     source="1.4" />

Full details can be found here.