How to notify the VM about certain event from Java code?

[Tony Guan]

Hi all,

I need to notify VM to take some action at certain point of the java
execution, how can I do that without creating special bytecode?

for example:
...
...system.out.println("this is part of java code");
functionCall_XXX();
......system.out.println("this is part of java code");

I need some functionCall_XXX() which will enable me to communicate
with the JVM, so that I can do something at this point. Does such
function exist?

Thanks!

Tony