Java key value

Get the Key for a Value from a Java Map | Baeldung
https://www.baeldung.com/java-map-key-from-value

Get a Value by Key in a JSONArray | Baeldung
https://www.baeldung.com/java-jsonarray-get-value-by-key

Java – Check if key exists in HashMap – Mkyong.com
https://www.mkyong.com/java/java-check-if-key-exists-in-hashmap/