java.lang.IndexOutOfBoundsException: Index 0 out of bounds for length 0 code example
Example: java.lang.indexoutofboundsexception: index: 0, size: 0
The problem is that you are using set method to update element at index 0
set(index,value) method needs an element to present at that index
but you haven't added any element at that position in medium arraylist before that .
So you need to first add an element at index 0 thereafter only you can update it with set method