java - How can I insert data between 2 nodes? -

don't know how it, need that, rest of code ok have insert number between numbers 8 , 10

class arra{ private arraylist<integer> lista; arra(){     lista = new arraylist<integer>(); }  public void cargar(int i){     lista.add(i); }  public arraylist <integer> traer(){     return lista; }  public void insertarinicio(int i){     lista.add(0,i); }  } public class trabclase {  public static void main(string[] args) {     // todo code application logic here     arraylist<integer> li = new arraylist<integer>();     arra obj = new arra();     int i=0;      for(i=2;i<=10;i=i+2){         obj.cargar(i);     }      li = obj.traer();     system.out.println("lista: ");     system.out.println(li);      obj.cargar(14);     system.out.println("lista adicionando el 14 al final ");     system.out.println(li);      system.out.println("lista adicionando un valor al inicio");     obj.insertarinicio(0);     system.out.println(li);    }  } 

if can tell me how it, realy appreciate it, first of all, thanks

simply li.add(5, 9); 5 index number , 9 number want add.