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

For Android development targeting API < 19, Vitalii Fedorenko one-to-one relationship solution doesn't work because Objects.equals isn't implemented. Here's a simple alternative:

public  K getKeyByValue(Map map, V value) {
    for (Map.Entry entry : map.entrySet()) {
            if (value.equals(entry.getValue())) {
            return entry.getKey();
        }
    }
    return null;
}