Collection

This is the root interface in the collection hierarchy.

Comparator

This is a comparison function, which imposes a total ordering on some collection of objects.

Deque

This is a linear collection that supports element insertion and removal at both ends.

Enumeration

This is an object that implements the Enumeration interface generates a series of elements, one at a time.

EventListener

This is a tagging interface that all event listener interfaces must extend.

Formattable

This is the Formattable interface must be implemented by any class that needs to perform custom formatting using the ‘s’ conversion specifier of Formatter.

Iterator

This is an iterator over a collection.

List

This is an ordered collection (also known as a sequence).

ListIterator

This is an iterator for lists that allows the programmer to traverse the list in either direction, modify the list during iteration, and obtain the iterator’s current position in the list.

Map

This is an object that maps keys to values.

Map.Entry

This is a map entry (key-value pair).

NavigableMap

This is a SortedMap extended with navigation methods returning the closest matches for given search targets.

NavigableSet

This is a SortedSet extended with navigation methods reporting closest matches for given search targets.

Observer

This is a class can implement the Observer interface when it wants to be informed of changes in observable objects.

Queue

This is a collection designed for holding elements prior to processing.

RandomAccess()

This is the Marker interface used by List implementations to indicate that they support fast (generally constant time) random access.

Set

This is a collection that contains no duplicate elements.

SortedMap

This is a Map that further provides a total ordering on its keys.

SortedSet

This is a Set that further provides a total ordering on its elements.