设计模式——建造者模式

HeadFirst中并没有把建造者模式（生成器模式）当做常用的设计模式来讲解，只是在附录中一带而过。

建造者模式的本质：
分离了对象组件的单独构造（由Builder来负责）和装配（由Director）来负责。从而可以构建出复杂的对象。这个模式适用于：某个对象的构建
过程复杂的情况先使用。由于实现了构建和装配的解耦。不同的构建器，相同的装配，也可以做出不同的对象相同的构建器不同的装配顺序也可以

做出不同的对象。也就是实现了构建算法、装配算法的解耦，实现了更好的复用。

Demo：

package com.wxisme.builder;

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

private OrbitalModule orbitalModule;  //轨道仓
private Engine engine; //发动机
private EscapeTower escapeTower;  //逃逸塔

public void launch(){
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 EscapeTower getEscapeTower() {
return escapeTower;
}
public void setEscapeTower(EscapeTower escapeTower) {
this.escapeTower = escapeTower;
}

}

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 EscapeTower{
private String name;

public String getName() {
return name;
}

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

public EscapeTower(String name) {
super();
this.name = name;
}

}

public interface AirShipBuilder {
Engine builderEngine();
OrbitalModule builderOrbitalModule();
EscapeTower  builderEscapeTower();
}

public interface AirShipDirector {

AirShip   directAirShip();

}

public class MyAirShipBuilder implements AirShipBuilder {

//StringBuilder, 以后学习XML解析中，JDOM库中的类：DomBuilder,SaxBuilder
@Override
public Engine builderEngine() {
System.out.println("构建发动机");
return new Engine("MyEngine");
}

@Override
public EscapeTower builderEscapeTower() {

System.out.println("构建逃逸塔");
return new EscapeTower("MyEscapeTower");
}

@Override
public OrbitalModule builderOrbitalModule() {
System.out.println("构建轨道仓");
return new OrbitalModule("MyOrbitalModule");
}

}

public class MyAirshipDirector implements AirShipDirector {

private AirShipBuilder builder;

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

@Override
public AirShip directAirShip() {
Engine e = builder.builderEngine();
OrbitalModule o = builder.builderOrbitalModule();
EscapeTower et = builder.builderEscapeTower();

//装配飞船对象
AirShip ship = new AirShip();
ship.setEngine(e);
ship.setEscapeTower(et);
ship.setOrbitalModule(o);

return ship;
}

}

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

AirShipDirector director = new MyAirshipDirector(new MyAirShipBuilder());

AirShip ship = director.directAirShip();

System.out.println(ship.getEngine().getName());

ship.launch();

}
}