As a developer, you can also create your own custom events using the JFR API and view and analyze them using MC. Here's an example; let's define a custom event:

class MyEvent extends Event { 
   @Label("EventMessage") 
   String message; 
} 

Now let's modify the AThread class to use events, instead of printing to console:

class AThread implements Runnable { 
    String name = "default"; 
    private Random numGenerator = new Random(); 
    private ArrayList<Double> list = new ArrayList<Double>(1000000); 
 
    AThread(String name) { 
        this.name = name; 
    } 
 
    public void run() { 
        MyEvent event; 
        for (int i = 0; i < 1000000; i++) { 
            list.add(numGenerator.nextDouble()); 
            event = new MyEvent(); 
            event.message = "Allocated : " + name + "[" + i + "]"; 
            event.commit(); 
        } 
    } 
} 
public class WithCustomEvents { 
    public static void main(String... args) throws Exception { 
        for (int i = 0; i < 500; i++) { 
            new Thread(new AThread("Thread" + i)).start(); 
        } 
    } 
} 

You can use the same command line options to execute your application, profiling it with JFR:

    > java 
      -XX:StartFlightRecording,filename=CustomEvents.jfr 
         WithCustomEvents

Now, instead of using MC to view these events, you can create another application that reads the logged events from CustomEvents.jfr, as follows:

class ReadFRData { 
    public static void main(String args[]) throws Exception { 
        Path p = Paths.get("CustomEvents.jfr"); 
        for (RecordedEvent e : RecordingFile.readAllEvents(p)) { 
           System.out.println(e.getStartTime() +  
                              " : " +  
                              e.getValue("message")); 
        } 
    } 
}