设计模式-23种设计模式-创建型-建造者模式

一、建造者模式介绍

UML类图：

二、建造者模式引入.

需求：

1.传统方式：

"产品"和"创建产品"的过程封装在一起。

代码实现(Java)：

public abstract class AbstractHouse {

    //打地基
    public abstract void buildBasic();
    //砌墙
    public abstract void buildWalls();
    //封顶
    public abstract void roofed();

    public void build() {
        buildBasic();
        buildWalls();
        roofed();
    }

}

public class CommonHouse extends AbstractHouse {

    @Override
    public void buildBasic() {
        System.out.println(" 普通房子打地基 ");
    }

    @Override
    public void buildWalls() {
        System.out.println(" 普通房子砌墙 ");
    }

    @Override
    public void roofed() {
        System.out.println(" 普通房子封顶 ");
    }

}

public class Client {

    public static void main(String[] args) {
        CommonHouse commonHouse = new CommonHouse();
        commonHouse.build();
    }

}

2.建造者模式：

UML类图：

代码实现(Java)：

//产品->Product
public class House {
    private String baise;
    private String wall;
    private String roofed;
    public String getBaise() {
        return baise;
    }
    public void setBaise(String baise) {
        this.baise = baise;
    }
    public String getWall() {
        return wall;
    }
    public void setWall(String wall) {
        this.wall = wall;
    }
    public String getRoofed() {
        return roofed;
    }
    public void setRoofed(String roofed) {
        this.roofed = roofed;
    }

}

// 抽象的建造者
public abstract class HouseBuilder {

    protected House house = new House();

    //将建造的流程写好, 抽象的方法
    public abstract void buildBasic();
    public abstract void buildWalls();
    public abstract void roofed();

    //建造房子好， 将产品(房子) 返回
    public House buildHouse() {
        return house;
    }

}

public class CommonHouse extends HouseBuilder {

    @Override
    public void buildBasic() {
        System.out.println(" 普通房子打地基5米 ");
    }

    @Override
    public void buildWalls() {
        System.out.println(" 普通房子砌墙10cm ");
    }

    @Override
    public void roofed() {
        System.out.println(" 普通房子屋顶 ");
    }

}

public class HighBuilding extends HouseBuilder {

    @Override
    public void buildBasic() {
        System.out.println(" 高楼的打地基100米 ");
    }

    @Override
    public void buildWalls() {
        System.out.println(" 高楼的砌墙20cm ");
    }

    @Override
    public void roofed() {
        System.out.println(" 高楼的透明屋顶 ");
    }

}

//指挥者，这里去指定制作流程，返回产品
public class HouseDirector {

    HouseBuilder houseBuilder = null;

    //构造器传入 houseBuilder
    public HouseDirector(HouseBuilder houseBuilder) {
        this.houseBuilder = houseBuilder;
    }

    //通过setter 传入 houseBuilder
    public void setHouseBuilder(HouseBuilder houseBuilder) {
        this.houseBuilder = houseBuilder;
    }

    //如何处理建造房子的流程，交给指挥者
    public House constructHouse() {
        houseBuilder.buildBasic();
        houseBuilder.buildWalls();
        houseBuilder.roofed();
        return houseBuilder.buildHouse();
    }
    
}

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

        //盖普通房子
        CommonHouse commonHouse = new CommonHouse();
        //准备创建房子的指挥者
        HouseDirector houseDirector = new HouseDirector(commonHouse);

        //完成盖房子，返回产品(普通房子)
        House house = houseDirector.constructHouse();
        System.out.println(house.getBaise());

        //System.out.println("输出流程");

        System.out.println("--------------------------");
        //盖高楼
        HighBuilding highBuilding = new HighBuilding();
        //重置建造者
        houseDirector.setHouseBuilder(highBuilding);
        //完成盖房子，返回产品(高楼)
        houseDirector.constructHouse();

    }
}