How to programmatically test if assertions are enabled?

I guess you should use Class.desiredAssertionStatus()

http://docs.oracle.com/javase/6/docs/api/java/lang/Class.html#desiredAssertionStatus()

I use this

boolean assertOn = false;
// *assigns* true if assertions are on.
assert assertOn = true; 

I am not sure this is the "official" way.