Generics and Auto-boxing not working together

Question

Why does the following code produce a compile error:
"Type mismatch: cannot convert from char to Character."
public class X<Character> {
     private Character c;
     private Integer i;
     public X() {
          c = 'a';
          i = 12;
}Note that if I change the class declaration to class X<Integer>, I'll get the error about converting from int to Integer, but the char error will disappear.

Answer 1

I believe that the <Character> type parameter is hiding the java.lang.Character class. Your code is equivalent to this:
public class X<T> {
     private T c;
     private Integer i;
     public X() {
          c = 'a';
          i = 12;
}So what you really want is something like
public class X<T> {
     private Character c;
     private Integer i;
     public X() {
          c = 'a';
          i = 12;
}or maybe this, depending on what you're really trying to do
public class X<T extends Character> {
     private T c;
     private Integer i;
     public X() {
          c = 'a';
          i = 12;
}Of course, since Character is final, that doesn't really make sense either.
Perhaps you could explain a bit more about what you're actually trying to accomplish.
Edited by: jverd on Feb 26, 2010 11:24 AM
Edited by: jverd on Feb 26, 2010 11:25 AM