ArrayList<String> list = new ArrayList<String>();
list.add(0, "0-element");
list.add(1, "1-element");
list.add(2, "2-element");

ArrayList<String> list = new ArrayList<String>();
list.add(1, "1-element");  // IndexOutOfBoundsException
list.add(2, "2-element");
list.add(0, "0-element");

if (pos>=list.size()) list.add(element);
else list.add(pos, element);

public void add(int index, E element) {
    if (index > size || index < 0)
        throw new IndexOutOfBoundsException(
        "Index: "+index+", Size: "+size);

    ensureCapacity(size+1);  // Increments modCount!!
    System.arraycopy(elementData, index, elementData, index + 1,
             size - index);
    elementData[index] = element;
    size++;
}

list.add("element1");
list.add("element2");
list.add("element3);

Throws:
IndexOutOfBoundsException - if the index is out of range (index < 0 || index > size())

List<String> list = new ArrayList<String>();
list.add("...");