建造者模式

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import java.util.ArrayList;
import java.util.List;

interface Packing {
String pack();
}

interface Item {
String name();
Packing packing();
float price();
}

class Wrapper implements Packing {

@Override
public String pack() {
return "Wrapper";
}
}

class Bottle implements Packing {

@Override
public String pack() {
return "Bottle";
}
}

abstract class Burger implements Item {

@Override
public Packing packing() {
return new Wrapper();
}

@Override
public abstract float price();
}

abstract class ColdDrink implements Item {

@Override
public Packing packing() {
return new Bottle();
}

@Override
public abstract float price();
}

class VegBurger extends Burger {

@Override
public float price() {
return 25.0f;
}

@Override
public String name() {
return "Veg Burger";
}
}

class ChickenBurger extends Burger {

@Override
public float price() {
return 50.5f;
}

@Override
public String name() {
return "Chicken Burger";
}
}

class Coke extends ColdDrink {

@Override
public float price() {
return 30.0f;
}

@Override
public String name() {
return "Coke";
}
}

class Pepsi extends ColdDrink {

@Override
public float price() {
return 35.0f;
}

@Override
public String name() {
return "Pepsi";
}
}

class Meal {
private List<Item> items = new ArrayList<Item>();

public void addItem(Item item){
items.add(item);
}

public float getCost(){
float cost = 0.0f;
for (Item item : items) {
cost += item.price();
}
return cost;
}

public void showItems(){
for (Item item : items) {
System.out.print("Item : "+item.name());
System.out.print(", Packing : "+item.packing().pack());
System.out.println(", Price : "+item.price());
}
}
}

class MealBuilder {

public Meal prepareVegMeal (){
Meal meal = new Meal();
meal.addItem(new VegBurger());
meal.addItem(new Coke());
return meal;
}

public Meal prepareNonVegMeal (){
Meal meal = new Meal();
meal.addItem(new ChickenBurger());
meal.addItem(new Pepsi());
return meal;
}
}

public class BuilderDemo {
public static void main(String[] args) {
MealBuilder mealBuilder = new MealBuilder();
Meal vegMeal = mealBuilder.prepareVegMeal();
System.out.println("Veg Meal");
vegMeal.showItems();
System.out.println("Total Cost: " +vegMeal.getCost());
}
}


建造者模式
https://wangqian0306.github.io/2020/design-pattern-builder/
作者
WangQian
发布于
2020年6月27日
许可协议