-Xlint warning when compiling with command prompt.

Question

1 of the method i write in the program has a compilation warning when compiling with command prompt. When i compile the codes with the application i used to write the program has no error at all. Below is my code:
private static ArrayList readNum(String NumFile)
ArrayList key = new ArrayList();
String keyAttributes = readInput(NumFile);
StringTokenizer stk = new StringTokenizer(keyAttributes);
while(stk.hasMoreTokens())
key.add(stk.nextToken());
return key;
When i javac the program with -X;int, this errror occured:
warning: [unchecked] unchecked call to add(E) as a member of the raw type java.util.ArrayList
key.add(stk.nextToken());
^
1 warning
Anyidea how to solve this problem? Thanks for the help.

Answer 1

A quick google for that message would have told you that you're not using generics and the compiler complains about that.
Google for "Java Generics" to find out what all the fuss is about.