Are there any Java-specific techniques (things which wouldnt apply to C++) for writing low latency code, in Java? I often see Java low latency roles and they ask for experience writing low latency Java- which sometimes seems a little bit of an oxymoron.

The only think I could think of is experience with JNI, outsourcing I/O calls to native code. Also possibly using the disruptor pattern, but thats not an actual technology.

Are there any Java specific tips for writing low latency code?

I am aware there is a Real Time Java Spec, but I have been warned real-time is not the same as low latency....