Uses of Class
java.util.HashSet

Packages that use HashSet
java.util Contains the collections framework, legacy collection classes, event model, date and time facilities, internationalization, and miscellaneous utility classes (a string tokenizer, a random-number generator, and a bit array). 
 

Uses of HashSet in java.util
 

Subclasses of HashSet in java.util
 class LinkedHashSet
          Hash table and linked list implementation of the Set interface, with predictable iteration order.