Task - Design Patterns - Builder Pattern with Factory Method

[akash-coded]

In the demonstrative code for the Builder pattern, the client (main() method) has to create an instance of a HouseBuilder and pass it for the instantiation of the CivilEngineer.

Your objective is to use the Factory Method pattern to eliminate the need to create an instance of a HouseBuilder by the client. The client should only interact with the CivilEngineer and provide the desired house to the CivilEngineer in the form of a String value.

You can refer to the Factory Method pattern demo code here. And, you can refer to this whiteboard for the illustrations and theoretical concepts of different design patterns.

The code without the Factory Method is given below. Incorporate the Factory Method pattern in it and post the solution in the comments.

interface HousePlan {
    void setBasement(String basement);

    void setStructure(String structure);

    void setRoof(String roof);

    void setInterior(String interior);
}

class House implements HousePlan {
    private String basement;
    private String structure;
    private String roof;
    private String interior;

    public void setBasement(String basement) {
        this.basement = basement;
    }

    public void setStructure(String structure) {
        this.structure = structure;
    }

    public void setRoof(String roof) {
        this.roof = roof;
    }

    public void setInterior(String interior) {
        this.interior = interior;
    }

    @Override
    public String toString() {
        return "House [basement=" + basement + ", interior=" + interior + ", roof=" + roof + ", structure=" + structure
                + "]";
    }
}

interface HouseBuilder {
    void buildBasement();

    void buildStructure();

    void buildRoof();

    void buildInterior();

    House getHouse();
}

class IglooHouseBuilder implements HouseBuilder {
    private House house;

    IglooHouseBuilder() {
        this.house = new House();
    }

    public void buildBasement() {
        house.setBasement("Ice Bars");
    }

    public void buildStructure() {
        house.setStructure("Ice Blocks");
    }

    public void buildRoof() {
        house.setRoof("Ice Dome");
    }

    public void buildInterior() {
        house.setInterior("Ice Carvings");
    }

    public House getHouse() {
        return house;
    }
}

class WoodenHouseBuilder implements HouseBuilder {
    private House house;

    WoodenHouseBuilder() {
        this.house = new House();
    }

    public void buildBasement() {
        house.setBasement("Wooden Poles");
    }

    public void buildStructure() {
        house.setStructure("Wood");
    }

    public void buildRoof() {
        house.setRoof("Twigs and Straws");
    }

    public void buildInterior() {
        house.setInterior("Wood Carvings");
    }

    public House getHouse() {
        return house;
    }
}

// Director
class CivilEngineer {
    private HouseBuilder houseBuilder;

    CivilEngineer(HouseBuilder houseBuilder) {
        this.houseBuilder = houseBuilder;
    }

    public void constructHouse() {
        this.houseBuilder.buildBasement();
        this.houseBuilder.buildStructure();
        this.houseBuilder.buildRoof();
        this.houseBuilder.buildInterior();
    }

    public House getHouse() {
        return this.houseBuilder.getHouse();
    }
}

// TODO:Incorporate factory method pattern to create house instances

public class BuilderDemo {
    public static void main(String[] args) {
        HouseBuilder woodenHouseBuilder = new WoodenHouseBuilder();
        CivilEngineer engineer = new CivilEngineer(woodenHouseBuilder);

        engineer.constructHouse();
        House house = engineer.getHouse();

        System.out.println("Finished house::\n" + house);
    }
}

[GouthamGunji]

updated Civil Engineer class code

class CivilEngineer {
	private HouseBuilder houseBuilder;

	CivilEngineer(String type) {
		this.houseBuilder = getHouseBuilder(type);
	}

	public void constructHouse() {
		this.houseBuilder.buildBasement();
		this.houseBuilder.buildStructure();
		this.houseBuilder.buildRoof();
		this.houseBuilder.buildInterior();
	}

	public House getHouse() {
		return this.houseBuilder.getHouse();
	}

	public HouseBuilder getHouseBuilder(String type) {
		switch (type) {
		case "Wood":
			return new WoodenHouseBuilder();
		case "Ice":
			return new IglooHouseBuilder();
		default:
			throw new IllegalArgumentException("Invalid House Type");
		}

	}

}

public class BuilderDemo {
	public static void main(String[] args) {

		CivilEngineer engineer = new CivilEngineer("Ice");

		engineer.constructHouse();
		House house = engineer.getHouse();

		System.out.println("Finished house::\n" + house);
	}
}

Screenshot

[kunalki]

Kishore Kunal

class CivilEngineer {
private HouseBuilding houseBuilding;

CivilEngineer(String type) {
	this.houseBuilding; = getHouseBuilding(type);
}

public void constructHouse() {
	this.houseBuilding.buildBasement();
	this.houseBuilding.buildStructure();
	this.houseBuilding.buildRoof();
	this.houseBuilding.buildExterior();
}

public House getHouse() {
	return this.houseBuilding.getHouse();
}

public HouseBuilder getHouseBuilding(String type) {
	switch (type) {
	case "Wood":
		return new WoodenHouseBuilding();
	case "Brick":
		return new BrickHouseBuilding();
	default:
		throw new IllegalArgumentException("Invalid House Type");
	}

}

}

public class BuilderDemo {
public static void main(String[] args) {

	CivilEngineer engineer = new CivilEngineer("Brick");

	engineer.constructHouse();
	House house = engineer.getHouse();

	System.out.println("Finished house::\n" + house);
}

}

[Thiripurasundari-1223]

Civil Engineer Class

class CivilEngineer {
	private HouseBuilder houseBuilder;
	private String houseModel;

	CivilEngineer(String houseModel) {
        this.houseModel = houseModel;
       
        }

	public void constructHouse() {
		this.houseBuilder.buildBasement();
		this.houseBuilder.buildStructure();
		this.houseBuilder.buildRoof();
		this.houseBuilder.buildInterior();
	}

	public House getHouse() {
		return this.houseBuilder.getHouse();
	}

	public void getHouseType() {
	
		if(this.houseModel.equals("IgloHouse")){
	 		this.houseBuilder = new IglooHouseBuilder();
	 	}else {
	 		this.houseBuilder = new WoodenHouseBuilder();
	 	}
	}
}

Driver class

public class BuilderDemo {
	public static void main(String[] args) {

		CivilEngineer engineer = new CivilEngineer("WoodenHouse");
		engineer.getHouseType();
		engineer.constructHouse();
		House house = engineer.getHouse();

		System.out.println("Finished house::\n" + house);
	}
}