What is a good way to pass useful state information to an exception in Java?

Question

I noticed some confusion initially with my question. I\'m not asking about how to configure a logger nor how to use a logger properly, but rather how to capture all of the infor

Answer 1

Take a look at the MemoryHandler class from java.util.logging. It acts as a buffer between your log.$level() invocations and the actual output, and will pass it's buffer content into the output only if some condition is met.

For example you could configure it to dump content only if it sees ERROR level message. Then you can safely output DEBUG level messages and no one will see them unless actual error occurs and then all messages are written to log file.

I would guess there are similar implementations for other logging frameworks.

EDIT: One possible issue with this approach is a performance lost on generating all the debug messages (see @djna comment). Because of this it could be a good idea to make the level of logging going into the buffer configurable - in production it should be INFO or higher, and only if you are actively hunting a problem down it could be turned down to DEBUG.