设计模式 之 建造者模式

简介

如果将抽象工厂模式看成汽车配件生产工厂, 生产一个产品簇的产品, 那么建造者模式就是一个汽车组装工厂, 通过对部件的组装可以返回一辆完整的汽车!

Director 分离模式

Director 指挥 worker 进行组装

public abstract class Builder {
    abstract void buildA();
    abstract void buildB();
    abstract void buildC();
    abstract void buildD();

    abstract Product getProduct();
}

public class Director {
    public Product build(Builder builder){
        builder.buildA();
        builder.buildB();
        builder.buildC();
        builder.buildD();
        return builder.getProduct();
    }
}

public class Product {
    private String buildA;
    private String buildB;
    private String buildC;
    private String buildD;

    public String getBuildA() {
        return buildA;
    }

    public String getBuildB() {
        return buildB;
    }

    public String getBuildC() {
        return buildC;
    }

    public String getBuildD() {
        return buildD;
    }

    public void setBuildA(String buildA) {
        this.buildA = buildA;
    }

    public void setBuildB(String buildB) {
        this.buildB = buildB;
    }

    public void setBuildC(String buildC) {
        this.buildC = buildC;
    }

    public void setBuildD(String buildD) {
        this.buildD = buildD;
    }

    @Override
    public String toString() {
        return "Product{" +
                "buildA='" + buildA + '\'' +
                ", buildB='" + buildB + '\'' +
                ", buildC='" + buildC + '\'' +
                ", buildD='" + buildD + '\'' +
                '}';
    }
}

public class Test {
    public static void main(String[] args) {
        Director d = new Director();
        Product build = d.build(new Worker());
        System.out.println(build.toString());
    }
}

package build;

/**
 * Created by lee on 2021/5/27.
 */
public class Worker extends Builder {
    private Product product;

    public Worker() {
        product = new Product();
    }
    @Override
    void buildA() {
        product.setBuildA("地基");
        System.out.println("地基");
    }

    @Override
    void buildB() {
        product.setBuildA("钢筋工程");
        System.out.println("钢筋工程");
    }

    @Override
    void buildC() {
        product.setBuildA("铺电线");
        System.out.println("铺电线");
    }

    @Override
    void buildD() {
        product.setBuildA("粉刷");
        System.out.println("粉刷");
    }

    @Override
    Product getProduct() {
        return product;
    }
}

UML

Director & worker 结合的模式

public abstract class Builder {
    abstract Builder buildA(String msg);
    abstract Builder buildB(String msg);
    abstract Builder buildC(String msg);
    abstract Builder buildD(String msg);

    abstract Product getProduct();
}

public class Product {
    private String BuildA = "汉堡";
    private String BuildB = "可乐";
    private String BuildC = "薯条";
    private String BuildD = "甜点";

    public String getBuildA() {
        return BuildA;
    }

    public void setBuildA(String buildA) {
        BuildA = buildA;
    }

    public String getBuildB() {
        return BuildB;
    }

    public void setBuildB(String buildB) {
        BuildB = buildB;
    }

    public String getBuildC() {
        return BuildC;
    }

    public void setBuildC(String buildC) {
        BuildC = buildC;
    }

    public String getBuildD() {
        return BuildD;
    }

    public void setBuildD(String buildD) {
        BuildD = buildD;
    }

    @Override
    public String toString() {
        return "Product{" +
                "BuildA='" + BuildA + '\'' +
                ", BuildB='" + BuildB + '\'' +
                ", BuildC='" + BuildC + '\'' +
                ", BuildD='" + BuildD + '\'' +
                '}';
    }
}

public class Test {
    public static void main(String[] args) {
        Worker worker = new Worker();
        //Product product = worker.getProduct();
        Product product = worker.buildA("全家桶").getProduct();
        System.out.println(product.toString());
    }
}

public class Worker extends Builder{
    private Product product;

    public Worker() {
        product = new Product();
    }

    @Override
    Builder buildA(String msg) {
        product.setBuildA(msg);
        return this;
    }

    @Override
    Builder buildB(String msg) {
        product.setBuildB(msg);
        return this;
    }

    @Override
    Builder buildC(String msg) {
        product.setBuildC(msg);
        return this;
    }

    @Override
    Builder buildD(String msg) {
        product.setBuildD(msg);
        return this;
    }

    @Override
    Product getProduct() {
        return product;
    }
}

UML