I have some library of classes, working with my data, which is being read into buffer. Is it possible somehow to avoid copying arrays again and again, passing parts of data deeper and deeper into processing methods? Well, it sounds strange, but in my particular case, there's a special writer, which divides data into blocks and writes them individually into different locations, so it just performs System.arraycopy, gets what it needs and calls underlying writer, with that new sub array. And this happens many times. What is the best approach to refactor such code?
Many classes in Java accept a subset of an arrays as parameter. E.g. Writer.write(char cbuf[], int off, int len). Maybe this already suffices for your usecase.