java.lang.indexoutofboundSexception: Index: 0, taille: 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
Santino