Java ConcurrentSkipListMap.floorEntry() is a method in the Java ConcurrentSkipListMap class that retrieves the entry with the largest key less than or equal to a specified key. It returns null if no such key exists. Introduced in Java 2004 with Java 5, floorEntry() is widely used in range queries and sorted map operations in concurrent environments.

https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ConcurrentSkipListMap.html