Why isn't Collections.binarySearch() working with this comparable?

Question

I have this Player class which implements the Comparable interface. Then I have an ArrayList of Players. I\'m trying to use <

Answer 1

Use are using generics inconsistently. Take heed of the compiler warnings. Always supply generic arguments (or never supply them).

Instead of:

class Player implements Comparable {
    [...]
    public int compareTo(Object o) {

Use

class Player implements Comparable {
    [...]
    public int compareTo(Player o) {

The rules of generics are difficult enough without the complication of rare types. So, typically the language spec gives up if you mix them up.