Sort Multiple Times on Hash Table

Question

I have a hash table that the key is id, value is a string of first name, last name, and age.
for example:
Hashtable showHT = new Hashtable();
showHT.put(person.getId(), person); <--- person is an object that contains all information
How to do sorting?
If I want to sort by id, last name, first name, and age, how can I do it.
I just know how to do once:
for exmpale, sorting by id:
Vector v = new Vector(showHT.keySet());
Collections.sort(v);
for (int i = 0; i < v.size(); i++)
     Integer key = (Integer) v.get(i);     
     String str = (String) showHT.get(key).toString();
     out.println(key + ": " +  str);
}How can I do the sorting by id, last name, first name, and age?
Thank you.

Answer 1

Given your "design", it is trivial to sort by id -- use a TreeMap .
Beyond that, you're going to have to face a basic fact: your design sucks. You are abusing Strings.
You need to:
1. Define a Person class
2. Define multiple Person Comparators
At that point you are essentially done.
[http://java.sun.com/docs/books/tutorial/collections/algorithms/index.html#sorting]
edit: or did I misread your vague code snippet? What type is person?