How to track when class is loaded and destroyed in jvm?

Question

How do I keep track when class is loaded and destroyed in jvm? Is there any callback method that is exposed by the jvm?

Answer 1

From Java 9 onward, you can use -Xlog. e.g.:

java -Xlog:class+load -Xlog:class+unload ...

This will print entries like:

[0.296s][info][class,load] java.lang.Shutdown source: jrt:/java.base
[0.296s][info][class,load] java.lang.Shutdown$Lock source: jrt:/java.base

You can also use -Xlog:help to get more information on the option.