如何删除使用装饰器设计模式添加的项目？例如披萨订购系统。我希望能够删除一些商品并降低价格。
public interface Pizza {
double getPrice();
}
public class SimplePizza implements Pizza {
@Override
public double getPrice() {
return 25;
}
}
public abstract class PizzaDecorator implements Pizza {
Pizza tempPizza;
public PizzaDecorator(Pizza a){
tempPizza = a;
}
@Override
public double getPrice(){
return tempPizza.getPrice();
}
}
public class Mushroom extends PizzaDecorator {
public Mushroom(Pizza newPizza){
super(newPizza);
}
public double getPrice(){
return tempPizza.getPrice() + 10;
}
}
最佳答案
这样做的可能方法之一:
interface Pizza {
double getPrice();
public abstract Pizza removeItem();
}
class SimplePizza implements Pizza {
@Override
public double getPrice() {
return 25;
}
@Override
public Pizza removeItem(){
return null;
}
}
abstract class PizzaDecorator implements Pizza {
Pizza tempPizza;
public PizzaDecorator(Pizza a){
tempPizza = a;
}
@Override
public double getPrice(){
return tempPizza.getPrice();
}
public abstract Pizza removeItem();
}
class Mushroom extends PizzaDecorator {
public Mushroom(Pizza newPizza){
super(newPizza);
}
public double getPrice(){
return tempPizza.getPrice()+10;
}
@Override
public Pizza removeItem(){
return tempPizza;
}
}
class Onion extends PizzaDecorator {
public Onion(Pizza newPizza){
super(newPizza);
}
public double getPrice(){
return tempPizza.getPrice()+20;
}
@Override
public Pizza removeItem(){
return tempPizza;
}
}
public class Main{
public static void main(String args[]){
Pizza pizza = new SimplePizza();
// create new FarmHouse pizza
Pizza pizza2 = new Mushroom(pizza);
System.out.println(pizza2.getPrice());//Prints 35.0
pizza2 = new Onion(pizza2);
System.out.println(pizza2.getPrice());////Prints 55.0
pizza2 = pizza2.removeItem();
System.out.println(pizza2.getPrice());//Print 35.0
}
}
关于java - 如何从装饰器模式中删除装饰对象？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/55776160/