建造者模式的原理就是一步步的建造複雜的對象。
/***
* 創建一個標識食物條目的接口
* @author gzl
*
*/
public interface Item {
public String name();//名稱
public Packing packing();//包裝
public float price();//價格
}
/***
* 表示食物包裝的接口
* @author gzl
*
*/
public interface Packing {
//該方法用於,定義Item類包裝的名稱
public String pack();
}
/***
* 創建包裝類的具體實現類Bottle
* @author gzl
*
*/
public class Bottle implements Packing {
@Override
public String pack() {
return "Bottle";
}
}
/***
* 創建包裝類的具體實現類Wrapper
* @author gzl
*
*/
public class Wrapper implements Packing {
@Override
public String pack() {
return "Wrapper";
}
}
/***
* 創建實現Item接口的抽象類Burger,該類只抽象出了包裝方法
* @author gzl
*
*/
public abstract class Burger implements Item {
@Override
public Packing packing() {
return new Wrapper();
}
}
/***
* 創建實現Item接口的抽象類ColdDrink,該類只抽象出了包裝方法
* @author gzl
*
*/
public abstract class ColdDrink implements Item {
@Override
public Packing packing() {
return new Bottle();
}
}
/***
* 創建擴展了Burger類的具體類ChickenBurger
* @author gzl
*
*/
public class ChickenBurger extends Burger {
@Override
public String name() {
return "Chicken Burger";
}
@Override
public float price() {
return 50.5f;
}
}
/***
* 創建擴展了Burger類的具體類VegBurger
* @author gzl
*
*/
public class VegBurger extends Burger {
@Override
public String name() {
return "Veg Burger";
}
@Override
public float price() {
return 25.0f;
}
}
public class Coke extends ColdDrink {
@Override
public String name() {
return "Coke";
}
@Override
public float price() {
return 30.0f;
}
}
public class Pepsi extends ColdDrink {
@Override
public String name() {
return "Pepsi";
}
@Override
public float price() {
return 35.0f;
}
}
/***
* 菜單類Meal
* @author gzl
*
*/
public 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.println("Item:"+item.name());
System.out.println(",Packing:"+item.packing().pack());
System.out.println(",Price:"+item.price());
}
}
}
/***
* 菜單創建者類MealBuilder
* @author gzl
*
*/
public 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;
}
}
/***
* 測試類
* @author gzl
*
*/
public class Test {
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());
Meal nonVegMeal = mealBuilder.prepareNonVegMeal();
System.out.println("\n\n------>Non-Veg Meal");
nonVegMeal.showItems();
System.out.println("Total Cost:"+nonVegMeal.getCost());
}
}