java decorator design pattern

Nitish Kumar answered on October 21, 2022 Popularity 7/10 Helpfulness 1/10

answer java decorator design pattern

related java decorator pattern

related Java Decorator design pattern example of implementation

java decorator design pattern

Comment

// Interface for the component that will be decorated
interface Component {
    void operation();
}

// Concrete implementation of the component
class ConcreteComponent implements Component {
    @Override
    public void operation() {
        System.out.println("ConcreteComponent operation");
    }
}

// Abstract decorator class
abstract class Decorator implements Component {
    protected Component component;

    public Decorator(Component component) {
        this.component = component;
    }

    @Override
    public void operation() {
        component.operation();
    }
}

// Concrete decorator class adding extra functionality
class ConcreteDecorator extends Decorator {
    public ConcreteDecorator(Component component) {
        super(component);
    }

    @Override
    public void operation() {
        super.operation();
        addExtraFunctionality();
    }

    private void addExtraFunctionality() {
        System.out.println("Added extra functionality");
    }
}

public class Main {
    public static void main(String[] args) {
        // Creating a concrete component
        Component component = new ConcreteComponent();

        // Decorating the component with extra functionality
        Component decoratedComponent = new ConcreteDecorator(component);

        // Calling the operation on the decorated component
        decoratedComponent.operation();
    }
}

Popularity 7/10 Helpfulness 1/10 Language java

Source: chat.openai.com

Tags: decorator java

Link to this answer
Share Copy Link

Contributed on Mar 22 2024

Nitish Kumar

0 Answers Avg Quality 2/10

Closely Related Answers

java decorator pattern

Comment

// Java Decorator pattern

public interface WebPage { // Component interface
	public void display();
}

public class BasicWebPage implements WebPage{ // Base Concrete Component
	public void display() {
		System.out.println("renders HTML to stylesheet, run scripts");
	}
}

public abstract class WebPageDecorator implements WebPage{
	// one instance of WebPage, allow stacking
	protected WebPage webpage;
	
	// constructor allow different subtypes of WebPage to
	// be linked together in a stack
	public WebPageDecorator (WebPage webpage) {
		this.webpage = webpage;
	}
	
	public void display() {this.webpage.display();}
}

public class AuthorizedWebPage extends WebPageDecorator{ // Concrete Decorator

	// constructor uses abstract superclass's constructor
	// allows decorators to be stacked together
	public AuthorizedWebPage(WebPage decoratedPage) {
		super(decoratedPage);
	}
	
	// each decorator has its own responsibility
	public void authorizedUser() {System.out.println("Authorizing user");}
	
	public void display() {
		// to resursively call the display() behavior
		// concrete decorators invoke superclass's display() method
		// call to super.display() will cause the next WebPage in the 
		// stack to execute its version until get to BasicWebPage, 
		// where recursion will end b/c BasicWebPage is a concrete component
		// which does not aggregate other types of WebPage
		super.display();
		this.authorizedUser();
	}
}

//Concrete Decorator
public class AuthenticatedWebPage extends WebPageDecorator{ 

	public AuthenticatedWebPage(WebPage decoratedPage) {
		super(decoratedPage);
	}
	
	public void authenticateUser() {
		System.out.println("Authenticating user");
	}
	
	public void display() {
		super.display();
		this.authenticateUser();
	}
}

public class Program {
	public static void main(String[] args) {
		// stacking objects into an aggregate
		// the order you build the stack matters ()
		WebPage myPage = new BasicWebPage();
		myPage = new AuthorizedWebPage(myPage);
		myPage = new AuthenticatedWebPage(myPage);
		// recursively invoke aggregation stack to combine behavior
		myPage.display();
	}
}

// renders HTML to stylesheet, run scripts
// Authorizing user
// Authenticating user

Popularity 10/10 Helpfulness 3/10 Language java

Source: Grepper

Tags: decorator deco

Link to this answer
Share Copy Link

Contributed on Oct 21 2022

Grotesque Gibbon

0 Answers Avg Quality 2/10

Java Decorator design pattern example of implementation

Comment

// The 'component' abstract class
public abstract class Beverage
{
	String description = "Unknown Beverage"

	public String getDescription()
	{
		return description;
	}

	public abstract double cost();
	// Other useful methods here

}

// The 'ConcreteComponent' classes
public class HouseBlend extends Beverage
{
	public HouseBlend()
	{
		description = "House Blend Coffee";
	}

	public cost double()
	{
		return 0.80;
	}
}

class DarkRoast extends Beverage 
{
	public DarkRoast()
	{
		description = "Dark Roast Coffee";
	}

	public double cost()
	{
		return 0.90;
	}
}


class Espresso extends Beverage
{
	public Espresso()
	{
		description = "Espresso";
	}

	public double cost()
	{
		return 1.99;
	}
}

class Decaf extends Beverage
{
	public Decaf()
	{
		description = "Decaf Coffee";
	}

	public double cost()
	{
		return 1.05;
	}
}

// The 'Decorator' abstract class
abstract class CondimentDecorator extends Beverage
{
	public abstract String getDescription();
}

// The 'ConcreteDecorator' classes
class Milk extends CondimentDecorator
{
	Beverage beverage;

	public Milk(Beverage beverage)
	{
		this.beverage = beverage;
	}

	public String getDescription()
	{
		return beverage.getDescription() + ", Milk";
	}

	public double cost()
	{
		return beverage.cost() + 10; // Assuming milk adds 0.10 to the cost
	}
}

Popularity 8/10 Helpfulness 1/10 Language java

Source: Grepper

Tags: decorator deco

Link to this answer
Share Copy Link

Contributed on Nov 10 2023

Depressed Donkey

0 Answers Avg Quality 2/10

java decorator design pattern

Contents

More Related Answers

java decorator design pattern

Closely Related Answers

java decorator pattern

Java Decorator design pattern example of implementation

Grepper

Documentation

Social

Legal

Contact

Oops, You will need to install Grepper and log-in to perform this action.