建造者模式

package com.test.design.builder;import java.util.ArrayList;public abstract class CarModel {private ArrayList<String> sequence = new ArrayList<String>();//protected 对外不用暴露那么多方法protected abstract void start();protected abstract void stop();protected abstract void engineBoom();protected abstract void alarm();public final void run(){int size = this.sequence.size();for(int i = 0; i < size; i++){if(this.sequence.get(i).equals("start")){this.start();}else if(this.sequence.get(i).equals("stop")){this.stop();}else if(this.sequence.get(i).equals("engineBoom")){this.engineBoom();}else if(this.sequence.get(i).equals("alarm")){this.alarm();}}}//设置方法调用顺序public final void setSequence(ArrayList<String> sequence){this.sequence = sequence;}}

package com.test.design.builder;public class BigCar extends CarModel {@Overrideprotected void alarm() {System.out.println("大车喇叭响了...");}@Overrideprotected void engineBoom() {System.out.println("大车引擎启动了...");}@Overrideprotected void start() {System.out.println("大车动起来了...");}@Overrideprotected void stop() {System.out.println("大车停下来了...");}}

package com.test.design.builder;public class SmallCar extends CarModel {@Overrideprotected void alarm() {System.out.println("小车喇叭响了...");}@Overrideprotected void engineBoom() {System.out.println("小车引擎启动了...");}@Overrideprotected void start() {System.out.println("小车动起来了...");}@Overrideprotected void stop() {System.out.println("小车停下来了...");}}

package com.test.design.builder;import java.util.ArrayList;public abstract class CarBuilder {public abstract CarModel getCarModel();public abstract void setSequence(ArrayList<String> sequence);}

package com.test.design.builder;import java.util.ArrayList;public class BigCarBuilder extends CarBuilder {private BigCar bigCar = new BigCar();@Overridepublic CarModel getCarModel() {return this.bigCar;}@Overridepublic void setSequence(ArrayList<String> sequence) {this.bigCar.setSequence(sequence);}}

package com.test.design.builder;import java.util.ArrayList;public class SmallCarBuilder extends CarBuilder {private SmallCar smallCar = new SmallCar();@Overridepublic CarModel getCarModel() {return this.smallCar;}@Overridepublic void setSequence(ArrayList<String> sequence) {this.smallCar.setSequence(sequence);}}

package com.test.design.builder;import java.util.ArrayList;public class Director {private ArrayList<String> sequence = new ArrayList<String>();private BigCarBuilder bigCarBuilder = new BigCarBuilder();private SmallCarBuilder smallCarBuilder = new SmallCarBuilder();public BigCar getABigCar(){this.sequence.clear();this.sequence.add("start");this.sequence.add("alarm");this.sequence.add("engineBoom");this.sequence.add("stop");this.bigCarBuilder.setSequence(this.sequence);return (BigCar)this.bigCarBuilder.getCarModel();}public BigCar getBBigCar(){this.sequence.clear();this.sequence.add("alarm");this.sequence.add("engineBoom");this.sequence.add("start");this.sequence.add("stop");this.bigCarBuilder.setSequence(this.sequence);return (BigCar)this.bigCarBuilder.getCarModel();}public SmallCar getASmallCar(){this.sequence.clear();this.sequence.add("start");this.sequence.add("alarm");this.sequence.add("engineBoom");this.sequence.add("stop");this.smallCarBuilder.setSequence(this.sequence);return (SmallCar)this.smallCarBuilder.getCarModel();}public SmallCar getBSmallCar(){this.sequence.clear();this.sequence.add("alarm");this.sequence.add("engineBoom");this.sequence.add("start");this.sequence.add("stop");this.smallCarBuilder.setSequence(this.sequence);return (SmallCar)this.smallCarBuilder.getCarModel();}}

package com.test.design.builder;public class Client {public static void main(String[] args) {Director director =  new Director();director.getABigCar().run();director.getBBigCar().run();director.getASmallCar().run();director.getBSmallCar().run();}}

建造者模式和工厂模式非常相似，它们的区别在于：建造者模式最主要功能是基本方法的调用顺序安排，也就是这些基本方法已经实现了；而工厂方法则重点是创建，你要什么对象我创造一个对象出来，组装顺序则不是他关心的。建造者模式使用的场景：产品类非常的复杂，或者产品类中的调用顺序不同产生了不同的效能，这个时候使用建造者模式是非常合适