Ну вот в принципе
package com.javarush.task.task14.task1411;
import java.io.BufferedReader;
import java.io.InputStreamReader;
/*
User, Loser, Coder and Proger
*/
public class Solution {
public static void main(String[] args) throws Exception {
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
Person person = null;
String key = null;
while ((key = reader.readLine()).matches("user|loger|coder|proger"));
{
while (true) {
key = reader.readLine();
if (key.equals("user")) {
Person.User user = new Person.User();
doWork(user);//создаем объект, пункт 2
} else if(key.equals("loser")) {
Person.Loser loser = new Person.Loser();
doWork(loser);
} else if(key.equals("coder")) {
Person.Coder coder = new Person.Coder();
doWork(coder);
} else if(key.equals("proger")) {
Person.Proger proger = new Person.Proger();
doWork(proger);
} else break;
}
}
}
public static void doWork(Person person) {
if (person instanceof Person.User) {
((Person.User) person).live();// пункт 3
} else if (person instanceof Person.Loser) {
((Person.Loser) person).doNothing();
} else if (person instanceof Person.Coder) {
((Person.Coder) person).writeCode();
} else if (person instanceof Person.Proger) {
((Person.Proger) person).enjoy();
}
}
}