Hi. I want to create a log file which is not directly intended to be readable by humans but to use with Pivot Tables in Excel to generate reports (e.g. over http requests and their duration spread over the day for several months, that kind of thing). I was wondering what the best approach for doing that would be. My guess would be a tab-separated file (to allow Excel to read it in as a CSV-file), with the first field being the timestamp in an Excel compatible form (e.g. a number formatted as a timestamp), and the remaining fields the individual items I need to analyze. (This is what I generate right now using ad-hoc Perl) (We can calculate on that 99.99% of the time that the application will exit with System.exit(0) in my main method, so it is not super important with having a solution robust against e.g. OutOfMemoryError, but I would like one that does not build a large data structure in memory like using JExcel to generate a spread sheet on the fly). Anyone who has experimented with this and have experiences to share? Thanks /Thorbjørn