It’s a little alarming how many good developers are unaware that many standard Java classes – including subclasses of Format – are not thread safe. Many are also not sure about how their applications perform in a multi-threaded environment or how their web application container (Tomcat) will run their app in multiple threads. This can cause nasty intermittent bugs that can be incredibly hard to find and fix. It’s important to be aware of threading issues at development time but it’s also important to be able to test for them.
Stuart 'Stevie' Leitch on Software Development, Java Technologies, Security and Testing