设计模式-建造者模式的应用

建造者模式的应用

实例：KFC套餐
建造者模式可以用于描述KFC如何创建套餐：套餐是一个复杂对象，它一般包含主食（如汉堡、鸡肉卷等）和饮料（如果汁、可乐等）等组成部分，不同的套餐有不同的组成部分，而KFC的服务员可以根据顾客的要求，一步一步装配这些组成部分，构造一份完整的套餐，然后返回给顾客。利用建造者模式设计，用JAVA语言实现 (或C#控制台应用程序实现)。绘制该模式的UML图。

【模式UML图】

【模式代码（JAVA语言实现）】
//SetMeal.java：

package sdp.sy_3.builderpattern;

//产品类：套餐――包括主食和饮料

public class SetMeal {
	String StapleFood;  //主食
	String Dringks;   //饮料
	
	public String getStapleFood() {
		return StapleFood;
	}
	public void setStapleFood(String stapleFood) {
		StapleFood = stapleFood;
	}
	public String getDringks() {
		return Dringks;
	}
	public void setDringks(String dringks) {
		Dringks = dringks;
	}
	
}

// SetMealBuilder.java:

package sdp.sy_3.builderpattern;

//抽象的Builder接口

public abstract class SetMealBuilder {
	SetMeal setMeal = new SetMeal();
	
	public abstract void createStapleFood();
	public abstract void createDrinks();
	
	public SetMeal getSetMeal() {
		return setMeal;
	}
	
}

// SetMealBuilderA.java:

package sdp.sy_3.builderpattern;

//套餐A：主食：汉堡+饮料：果汁

public class SetMealBuilderA extends SetMealBuilder{

	@Override
	public void createStapleFood() {
		setMeal.setStapleFood("Hamburger");
	}

	@Override
	public void createDrinks() {
		setMeal.setDringks("juice");
	}
	
}

// SetMealBuilderB.java:

package sdp.sy_3.builderpattern;

//套餐B：主食：鸡肉卷+饮料：可乐

public class SetMealBuilderB extends SetMealBuilder{

	@Override
	public void createStapleFood() {
		setMeal.setStapleFood("ChickenRolls");
	}

	@Override
	public void createDrinks() {
		setMeal.setDringks("Cola");
	}

}

// Director.java:

package sdp.sy_3.builderpattern;

public class Director {
	private SetMealBuilder setMealBuilder;
	
	public Director(SetMealBuilder setMealBuilder) {
		this.setMealBuilder = setMealBuilder;
	}
	
	public SetMeal construct() {
		//准备主食
		setMealBuilder.createStapleFood();
		//准备饮料
		setMealBuilder.createDrinks();
		//返回一个套餐
		return setMealBuilder.getSetMeal();
	}
}

// Client.java:

package sdp.sy_3.builderpattern;

//建造者模式

public class Client {

	public static void main(String[] args) {
		System.out.println("---------KFC套餐选择---------");
		
		//建造套餐A
		SetMealBuilder setMealABuilder = new SetMealBuilderA();
		Director kfcDirector = new Director(setMealABuilder);
		SetMeal kfcSetMealA = kfcDirector.construct();
		
		System.out.println("套餐A：");
		System.out.println("主食："+kfcSetMealA.getStapleFood()+" 饮料："+kfcSetMealA.getDringks());
		
		//建造套餐B
		SetMealBuilder setMealBBuilder = new SetMealBuilderB();
		kfcDirector = new Director(setMealBBuilder);
		SetMeal kfcSetMealB = kfcDirector.construct();
		
		System.out.println("套餐B：");
		System.out.println("主食："+kfcSetMealB.getStapleFood()+" 饮料："+kfcSetMealB.getDringks());
		
	}

}

【运行截图】