Question

How to set an acknowledgement (like email or SMS) before JVM shuts down (this is on the server side, not client)?

Answer 1

You need to add a ‘shutdown hook’ to the JVM, as described in the Runtime class:

http://java.sun.com/j2se/1.4.2/docs/api/java/lang/Runtime.html#addShutdownHook(java.lang.Thread)

If you wanted to print out a message when shutting down, you’d do:

Runtime.getRuntime().addShutdownHook(new Thread() { public void run() {
  System.out.println("Goodbye, world!");
} } );

Obviously, fill in the ‘goodbye world’ bit with what you want.