This document discusses the collection framework in Java. It provides an overview of the need for collections due to limitations of arrays. It then describes the key interfaces in the collection framework - Collection, List, Set, SortedSet, NavigableSet, Queue, Map, SortedMap, and NavigableMap. For each interface, it provides a brief description of its purpose and characteristics. It explains that collections allow storing heterogeneous data types with variable sizes, unlike arrays.

1. Collection Framework
concept in Java
Kumar Gaurav
k10gaurav@gmail.com

2. Need of collection framework?
 Due to limitation of arrays
 Arrays store homogenous data types only and fixed size
 Collections allowed to store heterogeneous data types with growable size
 Collection Framework is set of several classes and interfaces that helps to
achieve this target

3. 9 key interfaces of collection framework
 Collection
 List
 Set
 SortedSet
 NavigableSet
 Queue
 Map
 SortedMap
 NavigbleMap

4. 1- Collection
 Whenever we would like to represent a group of objects as a single entity,
we use Collection for the same
 It is also known as root interface of collections framework but not
completely
 There is no concrete class that implements collection interface directly
 It defines most common methods which are applicable on any collection
object -

5. 2- List
 List is child interface of Collection
 Representing a group of object as a single entity with the condition that -
 Duplicates are allowed
 Insertion order is preserved
 Duplicates identified by index
 Preserving insertion order by index
 Index has very important role

6. 3- Set
 It is child interface of Collection
 Representing a group of object as a single entity with the condition that -
 Duplicates are not allowed
 Insertion order is not preserved

7. 4- SortedSet
 It is child interface of Set
 Representing a group of object as a single entity with the condition that -
 Duplicates are not allowed
 Insertion order is not preserved
 Objects should be stored in some sorted order

8. 5- NavigableSet
 It is child interface of SoretdSet
 It defines several methods for navigation purpose
 TreeSet is the implementation class

9. 6- Queue
 It is the child interface of Collection
 If we want to represent a group of objects prior to processing then we
should go for Queue
 For e.g. suppose we have to send email to 100 email id’s so we have to store it
somewhere and the emails will be delivered in the same order they were saved

10. Wait a min before next…
 All discussed 6 interfaces Collection, List, Set, SoretdSet, NavigableSet,
Queue meant for representing a group of individual object as a single
entity
 If we want a represent group of objects as key-value pairs then we should
go for Map interface

11. 7- Map
 Map interface is not the child of Collection interface
 If we want to represent a group of objects as key-value pairs then should
go for Map
 Both key and value are objects
 Duplicate key is not allowed, value can be duplicate

12. 8- SortedMap
 It is the child interface of Map
 If we want to represent a group of key value pairs as per some sorting
order then SortedMap is used

13. 9- NavigableMap
 It is the child interface of SoretdMap
 It defines several utility methods for navigation purpose
 TrreeMap is the implementation class

14. References
 Durgasoft java tutorial http://durgasoft.com/
 Oracle https://docs.oracle.com/javase/7/docs/api/java/util/Collections.html

15. Thank you!