设计模式学习笔记---建造者模式（Java版）

一、场景

建造一个复杂的产品。

二、本质

将一个复杂的构建与其表示相分离，使得同样的构建过程可以创建不同的表示。 [构建与表示分离，同构建不同表示]

与抽象工厂的区别：在建造者模式里，有个指导者，由指导者来管理建造者，用户是与指导者联系的，指导者联系建造者最后得到产品。即建造模式可以强制实行一种分步骤进行的建造过程。

建造模式是将复杂的内部创建封装在内部，对于外部调用的人来说，只需要传入建造者和建造工具，对于内部是如何建造成成品的，调用者无需关心。

举个简单的例子，如汽车，有很多部件，车轮，方向盘，发动机还有各种小零件等等，部件很多，但远不止这些，如何将这些部件装配成一部汽车，这个装配过程也很复杂（需要很好的组装技术）， builder模式就是为了将部件和组装分开。

三、示例

package com.lgd.builder;

/**
 * 宇宙飞船
 * @author Administrator
 *
 */
public class AirShip {

private OrbitalModule orbitalModuleString; //轨道舱
private Engine engineString; //发动机
private EscapeTower escapeTowerString; //逃逸仓

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

public OrbitalModule getOrbitalModuleString() {
return orbitalModuleString;
}
public void setOrbitalModuleString(OrbitalModule orbitalModuleString) {
this.orbitalModuleString = orbitalModuleString;
}
public Engine getEngineString() {
return engineString;
}
public void setEngineString(Engine engineString) {
this.engineString = engineString;
}
public EscapeTower getEscapeTowerString() {
return escapeTowerString;
}
public void setEscapeTowerString(EscapeTower escapeTowerString) {
this.escapeTowerString = escapeTowerString;
}


}

class OrbitalModule{
private String nameString;
public OrbitalModule(String name){
this.nameString = name;
}
public String getNameString() {
return nameString;
}
public void setNameString(String nameString) {
this.nameString = nameString;
}

}

class Engine{
private String nameString;
public Engine(String name){
this.nameString = name;
}
public String getNameString() {
return nameString;
}
public void setNameString(String nameString) {
this.nameString = nameString;
}

}

class EscapeTower{
private String nameString;
public EscapeTower(String name){
this.nameString = name;
}
public String getNameString() {
return nameString;
}
public void setNameString(String nameString) {
this.nameString = nameString;
}

}

package com.lgd.builder;

public interface AirShipBuilder {
Engine buliderEngine();
OrbitalModule buliderOrbitalModule();
EscapeTower builderEscapeTower();
}

package com.lgd.builder;

public class LgdAirShipBuilder implements AirShipBuilder{//StringBuilder 

@Override
public Engine buliderEngine() {
// TODO Auto-generated method stub
System.out.println("LGD构建发动机");
return new Engine("LGD发送机");
}

@Override
public OrbitalModule buliderOrbitalModule() {
System.out.println("LGD构建轨道舱");
return new OrbitalModule("LGD轨道舱");
}

@Override
public EscapeTower builderEscapeTower() {
System.out.println("LGD构建逃逸塔");
return new EscapeTower("LGD逃逸塔");
}

}

package com.lgd.builder;

public class LkxAirShipBuilder implements AirShipBuilder{
@Override
public Engine buliderEngine() {
// TODO Auto-generated method stub
System.out.println("LKX构建发动机");
return new Engine("LKX发送机");
}

@Override
public OrbitalModule buliderOrbitalModule() {
System.out.println("LKX构建轨道舱");
return new OrbitalModule("LKX轨道舱");
}

@Override
public EscapeTower builderEscapeTower() {
System.out.println("LKX构建逃逸塔");
return new EscapeTower("LKX逃逸塔");
}

}

==================

package com.lgd.builder;

public interface AirShipDirector {
//组装飞船
AirShip createAirShip();

}

package com.lgd.builder;

public class LgdAirShipDirector implements AirShipDirector{

private AirShipBuilder builder;

public LgdAirShipDirector(AirShipBuilder builder) {
super();
this.builder = builder;
}

@Override
public AirShip createAirShip() {
// TODO Auto-generated method stub
Engine engine = builder.buliderEngine();
OrbitalModule orbitalModule = builder.buliderOrbitalModule();
EscapeTower escapeTower = builder.builderEscapeTower();

//装配成飞船对象
AirShip ship = new AirShip();
ship.setEngineString(engine);
ship.setEscapeTowerString(escapeTower);
ship.setOrbitalModuleString(orbitalModule);
return ship;
}

}

package com.lgd.builder;

public class client {
public static void main(String[] args) {
AirShipDirector directorLgd = new AirShipDirectorImpl(new LgdAirShipBuilder());
AirShip shipLgd = directorLgd.createAirShip();
System.out.println(shipLgd.getEngineString().getNameString());
shipLgd.launch();

AirShipDirector directorLkx = new AirShipDirectorImpl(new LkxAirShipBuilder());
AirShip shipLkx = directorLkx.createAirShip();
System.out.println(shipLkx.getEngineString().getNameString());
shipLkx.launch();
}
}

运行结果：

LGD构建发动机
LGD构建轨道舱
LGD构建逃逸塔
LGD发送机
发射。
LKX构建发动机
LKX构建轨道舱
LKX构建逃逸塔
LKX发送机
发射。