java.util package

Enumeration: This method for enumerating sets of values.

Observer: This method for enabling classes to be observable objects.

BitSet: It is a set of bits.

Date: The current system date, as well as methods for generating and parsing dates.

Dictionary: It is an abstract class that maps between keys and values.

Hashtable: It is a hash table.

Observable: It is an abstract class for observable objects.

Properties: It is a hash table that contains behaviour for setting and retrieving persistent properties of the system.

Random: Utilities for generating random numbers.

Stack: It follows the last-in-first-out order.

StringTokenizer: Utilities for splitting strings into individual “token“.

Vector: It is a growable array of objects.