Contoh Factory pattern
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The factory pattern is a creational design pattern that provides a way to create objects without specifying the exact class of the object being created. It uses factory methods to deal with object creation. The factory pattern defines a common interface for creating objects but allows subclasses to determine which class to instantiate. The document describes implementing a factory pattern to create different shape objects like circle, rectangle and square by passing a string to the factory class to determine which object to return. It defines a shape interface and concrete classes, a factory class that returns the appropriate shape object based on the string, and a demo class that uses the factory to get shape objects.
![Square.java
public class Square implements Shape {
@Override
public void draw() {
System.out.println("Inside Square::draw() method.");
}
}
Circle.java
public class Circle implements Shape {
@Override
public void draw() {
System.out.println("Inside Circle::draw() method.");
}
}
Step 3
Create a Factory to generate object of concrete class based on given information.
ShapeFactory.java
public class ShapeFactory {
//use getShape method to get object of type shape
public Shape getShape(String shapeType){
if(shapeType == null){
return null;
}
if(shapeType.equalsIgnoreCase("CIRCLE")){
return new Circle();
} else if(shapeType.equalsIgnoreCase("RECTANGLE")){
return new Rectangle();
} else if(shapeType.equalsIgnoreCase("SQUARE")){
return new Square();
}
return null;
}
}
Step 4
Use the Factory to get object of concrete class by passing an information such as type.
FactoryPatternDemo.java
public class FactoryPatternDemo {
public static void main(String[] args) {
ShapeFactory shapeFactory = new ShapeFactory();
//get an object of Circle and call its draw method.
Shape shape1 = shapeFactory.getShape("CIRCLE");
//call draw method of Circle
shape1.draw();
//get an object of Rectangle and call its draw method.
Shape shape2 = shapeFactory.getShape("RECTANGLE");](https://image.slidesharecdn.com/factorypattern-161121021154/85/Contoh-Factory-pattern-2-320.jpg)
Contoh Factory pattern
- 1. http://www.tutorialspoint.com/design_pattern/factory_pattern.htm Copyright © tutorialspoint.com DESIGN PATTERN - FACTORY PATTERNDESIGN PATTERN - FACTORY PATTERN Factory pattern is one of most used design pattern in Java. This type of design pattern comes under creational pattern as this pattern provides one of the best ways to create an object. In Factory pattern, we create object without exposing the creation logic to the client and refer to newly created object using a common interface. Implementation We're going to create a Shape interface and concrete classes implementing the Shape interface. A factory class ShapeFactory is defined as a next step. FactoryPatternDemo, our demo class will use ShapeFactory to get a Shape object. It will pass information (CIRCLE / RECTANGLE / SQUARE) to ShapeFactory to get the type of object it needs. Step 1 Create an interface. Shape.java public interface Shape { void draw(); } Step 2 Create concrete classes implementing the same interface. Rectangle.java public class Rectangle implements Shape { @Override public void draw() { System.out.println("Inside Rectangle::draw() method."); } }
- 2. Square.java public class Square implements Shape { @Override public void draw() { System.out.println("Inside Square::draw() method."); } } Circle.java public class Circle implements Shape { @Override public void draw() { System.out.println("Inside Circle::draw() method."); } } Step 3 Create a Factory to generate object of concrete class based on given information. ShapeFactory.java public class ShapeFactory { //use getShape method to get object of type shape public Shape getShape(String shapeType){ if(shapeType == null){ return null; } if(shapeType.equalsIgnoreCase("CIRCLE")){ return new Circle(); } else if(shapeType.equalsIgnoreCase("RECTANGLE")){ return new Rectangle(); } else if(shapeType.equalsIgnoreCase("SQUARE")){ return new Square(); } return null; } } Step 4 Use the Factory to get object of concrete class by passing an information such as type. FactoryPatternDemo.java public class FactoryPatternDemo { public static void main(String[] args) { ShapeFactory shapeFactory = new ShapeFactory(); //get an object of Circle and call its draw method. Shape shape1 = shapeFactory.getShape("CIRCLE"); //call draw method of Circle shape1.draw(); //get an object of Rectangle and call its draw method. Shape shape2 = shapeFactory.getShape("RECTANGLE");
- 3. //call draw method of Rectangle shape2.draw(); //get an object of Square and call its draw method. Shape shape3 = shapeFactory.getShape("SQUARE"); //call draw method of circle shape3.draw(); } } Step 5 Verify the output. Inside Circle::draw() method. Inside Rectangle::draw() method. Inside Square::draw() method.