You can sort the String as is explained in this answer: Sort a single String in Java
char[] chars = original.toCharArray();
Arrays.sort(chars);
Once is sorted you only have to check that the last one in the array of chars is higher than your given hex value.
For EBCDIC you can add a comparator to the sort and order based on the EBCDIC instead.
char[] chars = original.toCharArray();
// I will convert my array of chars to array of Characters to use Arrays.sort
int length = Array.getLength(chars);
Character[] ret = new Character[length];
for(int i = 0; i < length; i++)
ret[i] = (Character)Array.get(chars, i);
// and now the important bit
Arrays.sort(ret, new Comparator<Character>() {
@Override
public int compare(Character arg0, Character arg1) {
// convert arg0 and arg1 to EBCDIC with whatever tools you have
return arg0InEBCDIC - arg1InEDBCIC;
}
});
Once you have an ordered array you just need to check the last element as I said.