   Does java have BST
  Does it have binarySearchTree ?I mean its not hard to implement this, but right now, I'd rather user the libraries if it has one.   
  The TreeMap class is implemented using a Red-Black tree.  Typically, standard libraries are concerned more with providing standard container interfaces along with complexity bounds rather than with the particular data structure which underlies an implementation of that interface.  This type of modularity makes a lot of sense.  Nonetheless, the Java TreeMap along with most (all?) implementations of the C++ library map are implemented using Red-Black trees which are self-balancing variants of BSTs.