The premain() method

A colleague of mine pointed me to the premain() method in Java. This method is useful, particularly, in cases where there is a need to add a jar while the system is coming up, the jars can be added to bootstrap classloader, cool! One use of this method is to start an agent to monitor the performance of the system and have some program listen on this port to aggregate the perf stats. I just came across a really cool utility that draws the sequence diagrams while the program is running. Interestingly, this tool is also loading the agent using the premain(). If you'd like to give this tool a try download JTracert from the google code!