App crashing when appending a new line using nline.setText("\n")

App crashing when appending a new line using nline.setText("\n")

I want to append new line in the text view of my app:
I used this code
textView.setText("part 1");
TextView nline = null;
nline.setText(" \n");
textView.setText("part 2");
My app is crashing as I go to the page which implements this.
Thanks in advance