Package java.util

Interface Summary
Collection Collection is the root of the collection hierarchy.
Iterator An Iterator is used to sequence over a collection of objects.
List List is a collection which maintains an ordering for its elements.
Map  
Map.Entry  
RandomAccess RandomAccess is implemented by List implementations that support fast (usually constant time) random access.
Set  
 

Class Summary
AbstractCollection AbstractCollection is an abstract implementation of the Collection interface.
AbstractList AbstractList is an abstract implementation of the List interface, optimized for a backing store which supports random access.
ArrayList ArrayList is an implementation of List, backed by an array.
Arrays Arrays contains static methods which operate on arrays.
HashMap An implementation of Map that offers constant time retrieval and amortized constant time insertion.
HashSet An implementation of Set that offers constant time retrieval and amortized constant time insertion.
 

Exception Summary
HashCodeNotOverriddenException This runtime exception is thrown if you put an object in a java.util.HashSet that has inherited its hashCode() method directly from java.lang.Object.
NoSuchElementException This runtime exception is thrown when trying to retrieve an element past the end of an Enumeration, or the first or last element from an empty Vector.