Get a Hashtable key given a value

Question

hi,
can anyone tell me how I get a the key of Hashtable value given the value. I cant see anything in the api, and having been trying to figure this out for hours.
Hashtable numbers = new Hashtable();
numbers.put("one", new Integer(1));
numbers.put("two", new Integer(2));
numbers.put("three", new Integer(3));
if say I had value Integer 2, how can I find the key of this if I didn't know the key.

Answer 1

I prefer HashMaps. You have to look for it yourself.import java.util.*;
public class Test3 {
  public static void main(String[] args) {
    String[] data = {"Zero","One","Two","Three","Four","Five","Six"};
    HashMap hm = new HashMap();
    for (int i=0; i<data.length; i++) hm.put(data, new Integer(i));
Random rand = new Random();
Set keys = hm.keySet();
for (int i=0; i<10; i++) {
Integer value = new Integer(rand.nextInt(data.length));
System.out.println("Looking for "+value);
for (Iterator iter=keys.iterator(); iter.hasNext();) {
Object key = iter.next();
if (value.equals(hm.get(key))) {
System.out.println(" Found key '"+key+"' with value '"+value+"'");
}You might think about a reverse hashmap or else letting us know what you are trying to do.