Usage of super

Question

I have written this class.
package sample;
import java.util.List;
public class GenericSample {
     public static <T extends Number> void print1(List<T> l) {
          for (Number i : l) {
               System.out.println(i);
     public static void print2(List<? extends Number> l) {
          for (Number i : l) {
               System.out.println(i);
     public static void print3(List<? super Integer> l) {
          for (Object i : l) {
               System.out.println(i);
     // Gives compile error, why ??????
     public static <T super Integer> void print4(List<T> l) {
          for (Object i : l) {
               System.out.println(i);
}The first three methods compile fine, but the fourth one gives a "compile" error. Seems like 'super' and 'extends' are treated differently by the compiler in similar contexts (comparing methods print1() and print4())
Please let me know if I am missing something. I am on Eclipse 3.1 with Sun JDK 5.0_05.

Answer 1

Type parameters cannot have a lower bound. The super keyword for specification of a lower bound is only permitted on wildcards. See http://www.AngelikaLanger.com/GenericsFAQ/FAQSections/TypeArguments.html#FAQ203 for details.