Java Hashmap: How to get key from value?

Question

If I have the value \"foo\", and a HashMap ftw for which ftw.containsValue(\"foo\") returns true, how can I

Answer 1

I'm afraid you'll just have to iterate your map. Shortest I could come up with:

Iterator> iter = map.entrySet().iterator();
while (iter.hasNext()) {
    Map.Entry entry = iter.next();
    if (entry.getValue().equals(value_you_look_for)) {
        String key_you_look_for = entry.getKey();
    }
}