构建者模式-第一种方式

/**
 * 建造者
 */
public abstract class Builder {
    // 地基
    public abstract void buildA();
    // 钢筋工程
    public abstract void buildB();
    // 粉刷
    public abstract void buildC();

    public abstract Product getProduct();
}

public class ConcreteBuilder extends Builder {
    private Product product;
    public ConcreteBuilder() {
        this.product = new Product();
    }
    @Override
    public void buildA() {
        product.setBuildA("地基");
    }
    @Override
    public void buildB() {
        product.setBuildB("钢筋工程");
    }
    @Override
    public void buildC() {
        product.setBuildC("粉刷");
    }
    @Override
    public Product getProduct() {
        return product;
    }
}

public class Product {
    private String buildA;
    private String buildB;
    private String buildC;
    public String getBuildA() {
        return buildA;
    }
    public void setBuildA(String buildA) {
        this.buildA = buildA;
    }
    public String getBuildB() {
        return buildB;
    }
    public void setBuildB(String buildB) {
        this.buildB = buildB;
    }
    public String getBuildC() {
        return buildC;
    }
    public void setBuildC(String buildC) {
        this.buildC = buildC;
    }
    @Override
    public String toString() {
        return "Product{" +
                "buildA='" + buildA + '\'' +
                ", buildB='" + buildB + '\'' +
                ", buildC='" + buildC + '\'' +
                '}';
    }
}

/**
 * 指挥者
 */
public class Director {

    public Product create(Builder builder) {
        builder.buildA();
        builder.buildB();
        builder.buildC();
        return builder.getProduct();
    }
}

public class TestBuilder {
    public static void main(String[] args) {
        Director director = new Director();
        Product product = director.create(new ConcreteBuilder());
        System.out.println(product); // Product{buildA='地基', buildB='钢筋工程', buildC='粉刷'}
    }
}