Java Puzzler #2

gistfile1.txt

What happens when this code is compiled/executed ?

public class A<T> {
    public List<T> listOfTs = new ArrayList<T>();
    public List<Long> listOfLongs = Arrays.asList(1l, 2l, 4l);
    
    public A(List<T> _t){ this.listOfTs = _t; }
    
    public static void main(String[] args){
        hello(new A<String>(Arrays.asList("1", "2", "4")));
    }
    
    public static void hello(A a){
        for(Long l : a.listOfLongs){ System.out.println( l ); } /* (1) */
        for(String s : a.listOfTs){ System.out.println(s); } /* (2) */
    }
}
1/ Doesn't compile at line (1)
2/ Doesn't compile at line (2)
3/ Doesn't compile at both lines (1) and (2)
4/ Exception at runtime at line (1)
5/ Exception at runtime at line (2)
6/ It display "1, 2, 4" in the console, two times (but heh, would I be dumb enough to ask you this question if it was this answer ?)


The answer is in the JLS : http://java.sun.com/docs/books/jls/third_edition/html/typesValues.html#112736 (thanks to @jnegre_org :-))