Java APIs

I am new to the Generics scene so I don't understand what the problem is.

Given the following code:

  public static ArrayList<String> removeRecursivePages(ArrayList<String> alPages)
  {
    if (alPages == null)
    {
      return null;
    }
    
    ArrayList<String> alReturn = (ArrayList<String>)alPages.clone();

I get the following warning at the last line:

Rules.java:198: warning: [unchecked] unchecked cast
found   : java.lang.Object
required: java.util.ArrayList<java.lang.String>
                ArrayList<String> alReturn = (ArrayList<String>)alPages.clone();
1 warning

I am compiling using NetBeans 5.0 on JDK 1.5.0_06.

My unit tests come out just fine, so it runs like it should, it just gets annoying every time I compile to see the warning.

Any ideas?

Thanks.