Insertion an object into a sorted list

Question

Hello
I have got class MySortedList which encloses List object.
class MySortedList {
private List list = new LinkedList();
public add(Object obj, Comparator cmp) {
Who knows how the add(Object, Comparator) method can be realized better?
All comments...

Answer 1

Why am I using the LinkedList?
It is not in principle. I can change this to
ArrayList, for example.
It is depend on what do I use MySortedList class for.
Can you suggest to use something else?LinkedLists are going to be the slowest way to do this. Even calling contains is slow. You have a sorted list but you have to iterate over all the preceeding elements to get at an element even though you know where it is.
There is also a problem with the general design. someone can call the method once with one Comparator and then again with a completely different comparator. For example, if you add 5 elements with a String comparator that sorts them alphabetically and then with a Comparator that sorts them in reverse alphabetically you could end up with a list like:
z, c, d, e, f, g
then you call it with t and the firs comparator and get:
t, z, d, r, f, g
It's then no longer in order with respect to either comparator and the whole thing is broken. You need to set the Comparator in the constructor.
Use an ArrayList and the code becomes:
public synchronized void add(Object obj)
        int index = Collections.binarySearch(list, obj, comparator);
        if (index == list.size()) list.add(obj);
        else if (index < 0) list.add((index * -1) - 1, obj);
}