Dyuichi Blog

java// Product
class Product {
    private String partA;
    private String partB;
    private String partC;

    public void setPartA(String partA) {
        this.partA = partA;
    }
    public void setPartB(String partB) {
        this.partB = partB;
    }
    public void setPartC(String partC) {
        this.partC = partC;
    }
    public void show() {
        System.out.println("Product: " + partA + " " + partB + " " + partC);
    }
}

// Builder
interface Builder {
    void buildPartA();
    void buildPartB();
    void buildPartC();
    Product getResult();
}

// ConcreteBuilder
class ConcreteBuilderX implements Builder {
    private Product product = new Product();

    @Override
    public void buildPartA() {
        product.setPartA("partA-X");
    }
    @Override
    public void buildPartB() {
        product.setPartB("partB-X");
    }
    @Override
    public void buildPartC() {
        product.setPartC("partC-X");
    }
    @Override
    public Product getResult() {
        return product;
    }
}

class ConcreteBuilderY implements Builder {
    private Product product = new Product();

    @Override
    public void buildPartA() {
        product.setPartA("partA-Y");
    }
    @Override
    public void buildPartB() {
        product.setPartB("partB-Y");
    }
    @Override
    public void buildPartC() {
        product.setPartC("partC-Y");
    }
    @Override
    public Product getResult() {
        return product;
    }
}

// Director
class Director {
    private Builder builder;

    public Director(Builder builder) {
        this.builder = builder;
    }
    public Product construct() {
        builder.buildPartA();
        builder.buildPartB();
        builder.buildPartC();
        return builder.getResult();
    }
}

// Client
public class BuilderPattern {
    public static void main(String[] args) {
        Director directorX = new Director(new ConcreteBuilderX());
        Director directorY = new Director(new ConcreteBuilderY());

        Product productX = directorX.construct();
        Product productY = directorY.construct();

        productX.show();
        productY.show();
    }
}