ArrayList of my objects, indexOf problem

Question

I have problem with Java\'s ArrayList. I\'ve created an Object, that contains two attributes, x and y. Now I\'ve loaded some object in my ArrayList. Problem is that I don\'t

Answer 1

I usually just use a map if i want to be able to fetch an object out of a collection based on one specific attribute value. I find that cleaner than having to iterate over lists.

Map map = new HashMap();

map.put(o1.getX(), o1);
map.put(o2.getX(), o2);

now, if i want the object that has an x-value of "foo", all it takes is

Object desiredObject = map.get("foo");

if order is important, consider a LinkedHashMap.