It would be a monumental task, since:
- The actual Java language and LotusScript language (ignoring built-in functions and classes) are radically different. One does not map cleanly to the other
- Depending on what you want to do, you may not have all the Domino Classes you need in Java. The Notes UI classes are only implemented in LotusScript, not Java.
- One saving grace is that all the back-end classes are mirrored between LotusScript and Java.
- Another issue is that object management is handled much more cleanly in LotusScript than Java. In Java, you have to be careful to recycle your objects manually, and in the correct order, otherwise you may get strangled by the Java garbage collector.
That's all I can think of offhand. Hope it helps!