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Get Key from Value from Singleton Map - Java

I am looking to retrieve key from the value for a SingletonMap

Map<String,String> map = Collections.singletonMap("key1", "value1");

I am looking for a easy way to get the key, based on value. Rather then way that I have done before. Which I feel is too much overhead for a singleTon Map.

public static List<String> getKey(String value, Map<String, String> map) 
{
    List<String> keys = new ArrayList<String>();
    for(Entry<String, String> entry:map.entrySet()) 
    {
        if(value.equals(entry.getValue())) 
        {
            keys.add(entry.getKey());
        }
    }
    return keys;
}

Any inputs or suggestion will be helpful.

Solution

  • A singleton map has exactly one entry in it, so you can just do this:

        Map<String,String> map = Collections.singletonMap("key1", "value1");

    String theOnlyKeyInTheMap = map.keySet().iterator().next();