- 建造者模式(Builder Pattern) 也叫生成器模式，其定义如下： Separate the construction of a complex object from its representation so that the same construction process can create different representations.(将一个复杂对象的构建与他的表示分离，是得同样的构建过程可以创建不同的表示。) 在建造者模式中，有如下4个角色：
- Product产品类 通常是实现了模板方法模式，也就是有模板方法和基本方法。
- Builder抽象建造者 规范产品的组件，一般是由子类实现。例子中的CarBuilder就属于抽象建造者。
- ConcreteBuilder具体建造者 实现抽象类定义的所有方法，并且返回一个组建好的对象。
- Director导演类 负责安排已有模块的顺序，然后告诉Builder开始建造，在上面的例子中就是我们的老大，xx公司找到老大，说我要这个或那个类型的车辆模型，然后老大就把命令传递给我，我和我的团队就开始拼命的建造，于是一个项目建设完毕了。 建造者模式的通用源码也比较简单，先看Product类，通常它是一个组合或继承（如模板方法模式）产生的类
package com.wzl.fea;
import java.util.ArrayList;
abstract class CarBuilder {
public abstract void setSequence(ArrayList<String> sequence);
public abstract CarModel getCarModel();
}
abstract class CarModel {
private ArrayList<String> sequence = new ArrayList<String>();
protected abstract void start();
protected abstract void stop();
protected abstract void alarm();
protected abstract void engineBoom();
final public void run() {
for (int i = 0; i < this.sequence.size(); ++i) {
String actionName = this.sequence.get(i);
if (actionName.equalsIgnoreCase("start")) {
this.start();
}
else if (actionName.equalsIgnoreCase("stop")) {
this.stop();
}
else if (actionName.equalsIgnoreCase("alarm")) {
this.alarm();
}
else if (actionName.equalsIgnoreCase("engine boom")) {
//如果是engine boom关键字
this.engineBoom();
}
}
}
final public void setSequence(ArrayList sequence){
this.sequence = sequence;
}
}
class BenzModel extends CarModel {
protected void alarm() {
System.out.println("奔驰车的喇叭声音是这个样子的...");
}
protected void engineBoom() {
System.out.println("奔驰车的引擎是这个声音的...");
}
protected void start() {
System.out.println("奔驰车跑起来是这个样子的...");
}
protected void stop() {
System.out.println("奔驰车应该这样停车...");
}
}
class BMWModel extends CarModel {
protected void alarm() {
System.out.println("宝马车的喇叭声音是这个样子的...");
}
protected void engineBoom() {
System.out.println("宝马车的引擎是这个声音的...");
}
protected void start() {
System.out.println("宝马车跑起来是这个样子的...");
}
protected void stop() {
System.out.println("宝马车应该这样停车...");
}
}
class BenzBuilder extends CarBuilder {
private BenzModel benz = new BenzModel();
@Override
public CarModel getCarModel() {
return this.benz;
}
@Override
public void setSequence(ArrayList<String> sequence) {
this.benz.setSequence(sequence);
}
}
class BMWBuilder extends CarBuilder {
private BMWModel bmw = new BMWModel();
@Override
public CarModel getCarModel() {
return this.bmw;
}
@Override
public void setSequence(ArrayList<String> sequence) {
this.bmw.setSequence(sequence);
}
}
class CarDirector {
private ArrayList<String> sequence = new ArrayList<>();
private BenzBuilder benzBuilder = new BenzBuilder();
private BMWBuilder bmwBuilder = new BMWBuilder();
public BenzModel getABenzModel(){
this.sequence.clear();
this.sequence.add("start");
this.sequence.add("stop");
this.benzBuilder.setSequence(this.sequence);
return (BenzModel)this.benzBuilder.getCarModel();
}
public BenzModel getBBenzModel(){
this.sequence.clear();
this.sequence.add("engine boom");
this.sequence.add("start");
this.sequence.add("stop");
this.benzBuilder.setSequence(this.sequence);
return (BenzModel)this.benzBuilder.getCarModel();
}
public BMWModel getCBMWModel(){
this.sequence.clear();
this.sequence.add("alarm");
this.sequence.add("start");
this.sequence.add("stop");
this.bmwBuilder.setSequence(this.sequence);
return (BMWModel)this.bmwBuilder.getCarModel();
}
public BMWModel getDBMWModel(){
this.sequence.clear();
this.sequence.add("start");
this.bmwBuilder.setSequence(this.sequence);
return (BMWModel)this.benzBuilder.getCarModel();
}
}
public class EpCarBuilder {
public static void main(String[] args) {
ArrayList<String> sequence = new ArrayList<String>();
sequence.add("engine boom");
sequence.add("start");
sequence.add("stop");
BenzBuilder benzBuilder = new BenzBuilder();
benzBuilder.setSequence(sequence);
BenzModel benz = (BenzModel)benzBuilder.getCarModel();
benz.run();
CarDirector director = new CarDirector();
//1万辆A类型的奔驰车
for(int i=0;i<2;i++){
director.getABenzModel().run();
}
//100万辆B类型的奔驰车
for(int i=0;i<3;i++){
director.getBBenzModel().run();
}
//1000万辆C类型的宝马车
for(int i=0;i<5;i++){
director.getCBMWModel().run();
}
}
}
