Java HotSpot Virtual Machine

Hi,

I'm stuck, I can't find any answers in the JNI tutorial, or in Sheng Liangs book.

I basically want to pass from Java to a C function a null 2D array of doubles, the C function to create a 2D array of doubles, which it then assigns to the passed array. Sheng Liangs book has an example where a 2D array is returned as a return value, but this doesn't help me since I have functions with more that one return value, so I have to use pass by reference.
Is this even possible with JNI?

Here my Java method signature:

 public native void createCont(int[] noges,
                                                     double[][] probEx,
                                                     double[][] probEx2,
                                                     double root);

I can't assigne probEx or probEx2 to anything other than null before I make this call and I have no idea what size these arrays will be.

Any suggestions here would be greatly appreciated.