Прошу объяснить подробно почему здесь необходимо использовать приведение типов, вооще не понимаю этого момента
package com.javarush.task.task14.task1415;
import java.util.ArrayList;
import java.util.List;
import java.util.*;
/*
Клининговый центр
*/
public class Solution {
public static void main(String[] args) {
List<Apartment> apartments = new ArrayList<Apartment>();
apartments.add(new OneRoomApt());
apartments.add(new TwoRoomApt());
apartments.add(new ThreeRoomApt());
cleanAllApartments(apartments);
}
public static void cleanAllApartments(List<Apartment> apartments) {
Iterator<Apartment> iterator = apartments.iterator();
while (iterator.hasNext()) {
if (apartments instanceof OneRoomApt) {
OneRoomApt.clean1Room();
}
else if (apartments instanceof TwoRoomApt){
clean2Rooms();
}
else if (apartments instanceof ThreeRoomApt) {
clean3Rooms();
}
}
}
static interface Apartment {
}
static class OneRoomApt implements Apartment {
void clean1Room() {
System.out.println("1 room is cleaned");
}
}
static class TwoRoomApt implements Apartment {
void clean2Rooms() {
System.out.println("2 rooms are cleaned");
}
}
static class ThreeRoomApt implements Apartment {
void clean3Rooms() {
System.out.println("3 rooms are cleaned");
}
}
}
Пример нормальной реализации: