не вижу где ошибка, а она где-то есть) проведите на путь истинны(да, знаю что Onkel - это не дедушка)
package com.javarush.task.task06.task0621;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
/*
Родственные связи кошек
*/
public class Solution {
public static void main(String[] args) throws IOException {
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
String onkelName = reader.readLine();
Cat catOnkel = new Cat(onkelName);
String grannyName = reader.readLine();
Cat catGrenny = new Cat(grannyName);
String daddyName = reader.readLine();
Cat catDaddy = new Cat(daddyName,null, catOnkel);
String motherName = reader.readLine();
Cat catMother = new Cat(motherName, catGrenny, null);
String sonName = reader.readLine();
Cat catSon = new Cat(sonName, catMother, catDaddy);
String daughterName = reader.readLine();
Cat catDaughter = new Cat(daughterName, catMother, catDaddy);
System.out.println(catOnkel);
System.out.println(catGrenny);
System.out.println(catDaddy );
System.out.println(catMother);
System.out.println(catDaughter);
System.out.println(catSon);
}
public static class Cat {
private String name;
private Cat parent;
private Cat parent2;
Cat(String name) {
this.name = name;
}
Cat(String name, Cat parent, Cat parent2) {
this.name = name;
this.parent = parent;
this.parent2 = parent2;
}
public Cat(Cat sonName, Cat catMother, Cat catDaddy) {
}
@Override
public String toString() {
if (parent == null && parent2 == null)
return "Cat name is " + name + ", no mother" + ", no father";
else if (parent == null && parent2 != null)
return "Cat name is " + name + ", no mother" + ", father is " + parent2.name;
else if (parent != null && parent2 == null)
return "Cat name is " + name + ", mother is " + parent.name + ", no father";
else return "Cat name is " + name + ", mother is " + parent.name + ", father is " + parent2.name;
}
}
}