Java OOP Features, Java Startup , Java , Real world Object mapping with java

1. Think With Java
Mapping Real World Object with Java

2. A Society ( Group of families)

3. A Society ( Group of families)
Everything in the World is an Object (Society,
Family, Human, Cat, Dog, Car, River)
A society is a group of families.
Families are collections of Family member.
Each Family member is Human or Non Human.
Each family member has some responsibilities
(Activity) and they have their own properties.
Family members are interconnected to each
other.

4. A Society ( Group of families)
Each member is a human or non human.
Human beings are persons.
Each Human has common behavior comes
from Animal.
Each family member uses their guardians
vehicle or their own.
Each and every Human being has their own
Address.

5. Humans(Objects) Behavior
Object is an entity which has
State: determined by the values of its
properties.
Behavior: determined by how an object
performs an activity.

6. Humans(Objects) Properties &
Behavior/Activity
Every human(Male / Female / Other) has
common properties and also they have their
Behavior.
Properties: Name, Head, Hands, Hair,
Eyes(color , size), Nose, Address.
Behavior: Walking, Running, Playing, Gaining
Knowledge, Talking.

7. Map Now the Real World
Objects

8. Java Class or Java Bean
A simple Object instance container.
It has some properties and behavior.
So we can map our real world objects through
Java .
Properties: nationalId,
name, Address,
vehicle, PassportInfo,
Occupation
Behavior: Walking,
Running, Shopping,
Talking, Cycling,Driving

9. Access Modifier in java for
properties and behavior
Public:
A declaration that is accessible to all classes
with keyword “public”
Private:
A declaration that is accessible only to the class
in which it is declared with “private”.

10. Access Modifier in java for
properties and behavior

11. Java OOP feature(Abstraction)
Customer should
know to buy something
BillingStaff should
know products pricing
and to generate bill.
Administrator should
product sell and to buy
new products to gain
business goal and to
manage everything in
ABSTRACTION: concept of identifying the essential details to be
known and ignoring the non-essential details from the perspective
of the end user.
Retail Shop Scenario

12. A simple Shopping Scenario
of Abstraction

13. Encapsulation
The Student don’t have to know the calculation
mechanism of Calculator.
He/she just know its use of button.
ENCAPSULATION: concept of hiding the internal
details and providing a simple interface to the end
user which ensures that the system can be used
without having to know how it works.

14. A Calculator Scenario
of Encapsulation

15. Inheritance
Each Human have some common behavior of
Animal.
Every family members are human or non-
human(Cat or dog).
Each Regular or Privileged Customer have
common Properties.

16. Different Inheritance

17. Inheritance
Allows to define the generalized and
specialized characteristics and behavior. Multiple Inheritance

18. Inheritance
Allows to define the generalized and
specialized characteristics and behavior.
Multi level Inheritance

19. Polymorphism
Let us revisit the payment activity in the retail shop
Paymlent of bill can be done in two modes
Cash(Calculation includes VAT)
totalAmount = purchaseAmount + VAT
Credit Card(Calculation includes processing charge and
VAT)
totalAmount = purchaseAmount + VAT+
processingCharge
POLYMORPHISM: concept which allows on
objecct/operation to behave differently in different
situations.
So ? Now it is payment(processingCharge) or
payment()?

20. Polymorphism
Polymorphism is the
capability of a method
to do different things
based on the object
that it is acting upon
Following concepts
demonstrate different
types of polymorphism
in java.
1) Method
Overloading
2) Method

21. Static Binding vs Dynamic
Binding
difference between static and dynamic
binding in Java.
Static binding happens at compile-time while
dynamic binding happens at runtime.
Binding of private, static and final methods
always happen at compile time since these
methods cannot be overridden. Binding of
overridden methods happen at runtime.
Java uses static binding for overloaded
methods and dynamic binding for overridden
methods.

22. Dynamic Polymorphism(dynamic
binding) example

23. Abstract class & abstract
Method
If you declare an abstract
method (discussed below)
in a class then you must
declare the class abstract
as well. you can’t have
abstract method in a non-
abstract class.

24. What is an interface
Interface looks like class but it is not a class. An
interface can have methods and variables just
like the class but the methods declared in
interface are by default abstract (only method
signature, no body). Also, the variables declared
in an interface are public, static & final by
default.
** java programming language does not
support multiple inheritance (we can do this
through Interface)

25. Interface and abstract
Interface provides complete abstraction as
none of its methods can have body. On the other
hand, abstract class provides partial
abstraction as it can have abstract and
concrete(methods with body) methods both.

26. Use of Interface

27. Use of Interface with “abstract”
keyword

28. Relationship in Java classes
Is A (Inheritance)
Has A (Aggregation)  Tightly coupled
Uses (Association)  Loosely coupled

29. Relationship in Java classes

30. What next. . . . . .
ORM = Object Relational Mapping
ORM Providers : JPA, Hibernate, Spring, OFBiz
MVC = Model View Controller
MVC provider : JSF, Hibernate, Spring, OFBiz
etc.

31. A Strong Tool : Collection Framework
To work with data in the local machine or
memory must use the collection framework.
Collections--> Set, List, ArrayList, Map,
LinkedHashMap

32. Collection Framework overview.

33. Collections Example

34. Questions & Answers
 Fun with Java :)

35. Thanks to all…
Md. Arifur Rahman
Junior Software Engineer,
Newgen Technology Limited, Bangladesh.