What is a good data structure for storing and searching 2d spatial coordinates in Java

Question

I am currently writing a plugin for a game where one feature includes the ability to set areas defined by 2 two dimensional coordinates ( The upper left and lower right areas of

Answer 1

A good datastructure for determining collision in a part of space is the quad-tree datastructure. The quad-tree recursively divides a space according to the number of elements in a given area. Thus it can do a search if coordinates are inside a region in logarithmic time.

EDIT: I have found an implementation here but no license information is given.