Example 1: 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 2: 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 3: 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 4: abstract class example in java
//abstract parent class
abstract class Animal{
//abstract method
public abstract void sound();
}
//Dog class extends Animal class
public class Dog extends Animal{
public void sound(){
System.out.println("Woof");
}
public static void main(String args[]){
Animal obj = new Dog();
obj.sound();
}
}
Example 5: Abstraction in java
// example on abstract class in java
import java.util.*;
// abstract class
abstract class Shape
{
// abstract method
abstract void sides();
}
class Triangle extends Shape
{
void sides()
{
System.out.println("Triangle shape has three sides.");
}
}
class Pentagon extends Shape
{
void sides()
{
System.out.println("Pentagon shape has five sides.");
}
public static void main(String[] args)
{
Triangle obj1 = new Triangle();
obj1.sides();
Pentagon obj2 = new Pentagon();
obj2.sides();
}
}
Example 6: java abstract
abstract class Pesan {
public void success() {
System.out.println("Mobil Berhasil Dibeli");
}
public void error() {
System.out.println("Uang Anda Tidak Cukup");
}
}
class Car extends Pesan {
protected String nama = "toyota supra";
protected String warna = "merah";
protected int harga = 2000000000;
protected String brand = "toyota";
}
class ShowRoom extends Car {
protected String namaShowroom = "Catur Sentosa Raya";
protected String alamatShowroom = "Jl.siliwangin kec pancoranmas kota depok 16436";
}
class Pembeli extends ShowRoom {
protected String namaPembeli = "anto jayabaya";
protected String alamatPembeli = "jl.swadaya rt.01/rw.04 no.112 kec pancoranmas kota depok";
protected int saldoPembeli = 50000000;
}
class BeliMobil extends Pembeli {
public BeliMobil(String nama, String warna, int harga, String brand, String nsr, String asr, String np, String ap, int sdp) {
super();
super.nama = nama;
super.warna = warna;
super.harga = harga;
super.brand = brand;
super.namaShowroom = nsr;
super.alamatShowroom = asr;
super.namaPembeli = np;
super.alamatPembeli = ap;
super.saldoPembeli = sdp;
}
void getResult(String nama, String warna, int harga, String brand, String np, String ap) {
if(super.harga > super.saldoPembeli) {
System.out.println("=======================");
super.error();
System.out.println("=======================");
} else {
System.out.println("=======================");
super.success();
System.out.println("=======================");
System.out.println("");
System.out.println("=======================");
System.out.println("Jenis Mobil");
System.out.println("=======================");
System.out.println("");
System.out.println("Nama Mobil:" + nama);
System.out.println("Warna Mobil:" + warna);
System.out.println("Harga Mobil:" + harga);
System.out.println("Brand Mobil:" + brand);
System.out.println("");
System.out.println("=======================");
System.out.println("Nama Pembeli Mobil");
System.out.println("=======================");
System.out.println("Nama Pembeli:" + np);
System.out.println("Nama Pembeli:" + ap);
}
}
public static void main(String[] args) {
BeliMobil beli = new BeliMobil("avanza", "hitam", 128000000, "toyota", "Jaya Mobil", "Jakarta", "Anton", "Depok", 228000000);
beli.getResult(beli.nama, beli.warna, beli.harga, beli.brand, beli.namaPembeli, beli.alamatPembeli);
}
}