The JVMs built in "Java Flight Recorder" (JFR) is a monitoring tool that collects information about the events during the execution of your Java Application.

To generate a JFR recording, add the argument -XX:StartFlightRecording=filename=recording.jfr to your java call.

The final commandline call could look something like this:

java -XX:StartFlightRecording=filename=recording.jfr -jar ./MyAppl.jar

Once the JFR recording file exists, drop the resulting JFR file into (https://www.speedscope.app/)

To view it offline, you'll need to install speedscope via npm:

npm install -g speedscope

Then you should be able to open it like so: