设计模式（五）Builder Pattern建造者模式

在我们日常生活中，如构建一个飞船，一个手机，一栋建筑，都会有非常复杂的组装，这时候应该用到建造者模式

以建造一个飞船为例

案例：造小页飞船

1.飞船各部分元件

package com.littlepage.BuilderPattern;

public interface AirShipBuilder {
    Engine builderEngine();
    OrbitalModule builderOrbitalModule();
    Escape builderEscape();
}    

2.飞船实体用来组装

package com.littlepage.BuilderPattern;

public class AirShip {
    private OrbitalModule orbitalModule;
    private Engine engine;
    private Escape escape;

    public void lauch(){
        System.out.println("发射");
    }

    public OrbitalModule getOrbitalModule() {
        return orbitalModule;
    }
    public void setOrbitalModule(OrbitalModule orbitalModule) {
        this.orbitalModule = orbitalModule;
    }
    public Engine getEngine() {
        return engine;
    }
    public void setEngine(Engine engine) {
        this.engine = engine;
    }
    public Escape getEscape() {
        return escape;
    }
    public void setEscape(Escape escape) {
        this.escape = escape;
    }

}
class OrbitalModule{
    private String name;

    public OrbitalModule(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

}

class Engine{
    private String name;

    public Engine(String name) {
        this.name=name;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

}

class Escape{
    private String name;

    public Escape(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

}

3.创造方法的接口

package com.littlepage.BuilderPattern;
/*
 *组装飞船对象
 */
public interface AirShipDirector {
    AirShip createAirship();
}

4.实现组件（小页飞船组件）

 package com.littlepage.BuilderPattern;

public class LittlePageShipBuilder implements AirShipBuilder{

    @Override
    public Engine builderEngine() {
        System.out.println("页牌发动机");
        return new Engine("页牌发动机");
    }

    @Override
    public OrbitalModule builderOrbitalModule() {
        System.out.println("页牌逃逸塔");
        return new OrbitalModule("页牌逃逸塔");
    }

    @Override
    public Escape builderEscape() {
        System.out.println("页牌轨道舱");
        return new Escape("页牌轨道舱");
    }

}

5.实体实现装配

package com.littlepage.BuilderPattern;

public class LittlePageAirshipDirector implements AirShipDirector{
    private AirShipBuilder builder;

    public LittlePageAirshipDirector(AirShipBuilder builder) {
        this.builder = builder;
    }

    @Override
    public AirShip createAirship() {
        Engine e=builder.builderEngine();
        OrbitalModule om=builder.builderOrbitalModule();
        Escape et=builder.builderEscape();

        AirShip ship=new AirShip();
        ship.setEngine(e);
        ship.setOrbitalModule(om);
        ship.setEscape(et);
        return ship;
    }

}

6.客户端的串接（测试）

package com.littlepage.BuilderPattern;

public class Client {
    public static void main(String[] args) {
        AirShipDirector dir=new LittlePageAirshipDirector(new LittlePageShipBuilder());
        AirShip air=dir.createAirship();
        System.out.println(air.getEngine());
        air.lauch();
    }
}

UML结构图