Example 1: abstract class in java
Sometimes we may come across a situation where we cannot provide
implementation to all the methods in a class. We want to leave the
implementation to a class that extends it. In such case we declare a class
as abstract.To make a class abstract we use key word abstract.
Any class that contains one or more abstract methods is declared as abstract.
If we don’t declare class as abstract which contains abstract methods we get
compile time error.
1)Abstract classes cannot be instantiated
2)An abstarct classes contains abstract method, concrete methods or both.
3)Any class which extends abstarct class must override all methods of abstract
class
4)An abstarct class can contain either 0 or more abstract method.
Example 2: abstraction in java
Abstraction is defined as hiding internal implementation and showing only
necessary information.
// abstract class
abstract class Addition
{
// abstract methods
public abstract int addTwoNumbers(int number1, int number2);
public abstract int addFourNumbers(int number1, int number2, int number3, int number4);
// non-abstract method
public void printValues()
{
System.out.println("abstract class printValues() method");
}
}
class AbstractMethodExample extends Addition
{
public int addTwoNumbers(int number1, int number2)
{
return number1 + number2;
}
public int addFourNumbers(int number1, int number2, int number3, int number4)
{
return number1 + number2 + number3 + number4;
}
public static void main(String[] args)
{
Addition add = new AbstractMethodExample();
System.out.println(add.addTwoNumbers(6, 6));
System.out.println(add.addFourNumbers(8, 8, 3, 2));
add.printValues();
}
}
Example 3: abstraction in java
Abstraction is nothing but the quality of dealing with ideas rather than
events. It basically deals with hiding the internal details and showing
the essential things to the user.
Example 4: what is abstraction in java
Sometimes we may come across a situation
where we cannot provide implementation to
all the methods in a class. We want to leave the
implementation to a class that extends it.
In that case we declare a class
as abstract by using abstract keyword on method
signature.In my framework I have created my
PageBase class as super
class of the all page classes.
I have collected all common elements
and functions into PageBase class and
all other page classes extent PageBase class.
By doing so, I don't have to locate very
common WebElements and it provides
reusability in my framework.
Also
1)Abstract classes cannot be instantiated
2)An abstarct classes contains abstract method,
concrete methods or both.
3)Any class which extends abstarct class must
override all methods of abstract class
4)An abstarct class can contain either
0 or more abstract method.
Example 5: abstraction in java
Sometimes we may come across a situation
where we cannot provide implementation to
all the methods in a class. We want to leave the
implementation to a class that extends it.
In that case we declare a class
as abstract by using abstract keyword on method
signature.In my framework I have created my
PageBase class as super
class of the all page classes.
I have collected all common elements
and functions into PageBase class and
all other page classes extent PageBase class.
By doing so, I don't have to locate very
common WebElements and it provides
reusability in my framework.
Also
1)Abstract classes cannot be instantiated
2)An abstarct classes contains abstract method,
concrete methods or both.
3)Any class which extends abstarct class must
override all methods of abstract class
4)An abstarct class can contain either
0 or more abstract method.
Example 6: abstraction java
bstraction: Hiding the implementation details,
concentrating on essentials things,
without worrying about the details
■ In java, abstraction is achieved via abstract class or interface
■ Abstraction cannot exist without inheritance
3.1. Abstract class a class that's meant to be inherited
(cannot be private or final)
■ To create an abstract class: add keyword abstract
before the class declaration
■ A class that we cannot create object
when abstract class extended by regular class:
we MUST override all the abstract methods of super class
when abstract class extended by abstract class:
no need to override any abstract methods
abstract class vs non-abstract class:
NON-ABSTRACT CLASS:
cannot have: abstract methods
can have: constructor, instance method, static method,
instance block, static block, instance variable, static variable
ABSTRACT CLASS:
can have: constructor, instance method, static method, instance block,
static block, instance variable, static variable...
ABSTRACT METHOD: method without implementation, meant to be override
(cannot create object, cannot be final,static,private)
FRAMEWORK EXAMPLE:
In my framework I have achieved abstraction by using collections
or Map, because it’s all interface. Most of the cases I come
across using List. If we want to access elements frequently
by using index, List is a way to go. ArrayList provides
faster access if we know index. If we want to store elements and
want them to maintain an order, List is a better choice.
i) List webs = driver.getWindowHandles();
=>create a list first to store web URLs in list
ii)To handle dynamic elements store it in the list and identify by index
List all = driver.findElements(By.tagname(“”));
In my framework I follow POM and had situations where some pages
shared similar actions that were similar but worked slightly
different, so I was able to use abstraction to define those
actions and implement them in each page according to what was needed
for that webpage