Passing any enum type to a method

Question

Consider I have created some enums:
public enum Day {
    SUN, MON, TUE, WED, THU, FRI, SAT
public enum Month {
    JAN, FEB, MAR, APR, MAY, JUN, JUL, AUG, SEP, OCT, NOV, DEC
}I want to create a method that will accept any type of enum and display all values. So the call would look something like:
showAll(Day);
showAll(Month);I'm not sure what to pass to the method. My understanding of Generics is rudimentary at best, despite reading the tutorial several times now. Here is some uncompilable code that might illustrate:
public void showAll(EnumType enumType)  // <--- not sure what to pass here
  Enum[] allValues = enumType.values();
  // then, loop over the allValues array and I can proceed from here
}The actual code is needed is for displaying a list of checkboxes to the user where the input is the enum class, and the checkboxes are every enum value.

Answer 1

brucechapman wrote:
You could use this signature
<T extends Enum<T>> void showall(Class<T> clazz); Then use reflection to invoke the values() method which you know is there because only Class objects for enums can be passed in.I'll be honest, that signature looks very strange to me. However, I tried it anyway and it worked even without reflection.
public class PassingEnums
  public enum Day {
    SUN, MON, TUE, WED, THU, FRI, SAT
  public enum Month {
    JAN, FEB, MAR, APR, MAY, JUN, JUL, AUG, SEP, OCT, NOV, DEC
  public <T extends Enum<T>> void showAll(Class<T> clazz)
    T[] types = clazz.getEnumConstants();
    for (int i = 0; i < types.length; i++)
      System.out.println(types.toString());
public static void main(String[] args)
PassingEnums test = new PassingEnums();
test.showAll(Day.class);
System.out.println("---");
test.showAll(Month.class);
}Or were you thinking of something else?
I guess I'll have to hit the tutorials again, since that signature looks foreign to me.
Thanks.