Enums and generic classes

Question

Hi all,
consider the following class:
public class Box<T> {
  // omitted
}Suppose I create an Enum like so:
public enum BoxEnum {
    FIRST_BOX("Box1", String.class), SECOND_BOX("Box2", Integer.class);
    private final String name;
    private final Class<?> classType;
    // The starting point of the problem
    private static Map<String, Box<?>> map;
    static {
        map = new Hashtable<String, Box<?>>();
        for (BoxEnum i : BoxEnum.values()) {
            map.put(i.getName(), new Box<Same Type as classType>());
            // note the error in the upper line
    BoxEnum(String name, Class<?> classType) {
        this.name = name;
        this.classType = classType;
    public String getName() {
        return name;
    @SuppressWarnings("unchecked")
    public <T> T getClassType() {
        return (T) classType;
}Note where the problem occurs; what I am trying to achieve is to populate a Map. Moreover, I should be able to create a new Box holding the exact same data that is specified in the Enum constant. To be more precise, consider the following example:
FIRST_BOX("Box1", String.class)the program should populate a Map so that the key would be "Box1" and the value would be "new Box<String>()".
Is there a way to achieve this?
Thank you.

Answer 1

Hi, thank you for a quick response.
I'm not really sure if I understand your reply correctly, or maybe I was not clear enough describing my question. I did try a few different approaches with your suggestion but none of them worked, so I'll try to show one more example, to make this clearer (or so I hope)
// This is where it goes down:
private static Map<String, Box<?>> map;
    static {
        map = new Hashtable<String, Box<?>>();
        for (BoxEnum i : BoxEnum.values()) {
            // This is the fundamental part; this is where the new Box
            // should be created, having the same data type as its
            // enum constant, thus if i == 0, then:
            String name = i.getName();  // "Box1"
            Class<?> cls = i.getClassType() // this method was corrected, please note below
            map.put(name, new Box<cls>());  // please note the cls variable; here's the error
  // the corrected method
public <T> T getClassType() {
        return (T) classType.newInstance();
}