Relation between mother an child [closed]

Question

I have 2 classes : Mother and Child + ofcourse an Main. Class Mother:

public class Mother extends Child {

    private int id;
    private String name;
    private int age;

    public Mother(int id, String name, int age) {
        super();
        this.id = id;
        this.name = name;
        this.age = age;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "Mother{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}

Class Child:

public class Child {
    private String name;
    private int age;

    public Child(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public Child() {

    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "Child{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}

I have to make a relation between the classes that a mother can have many childs but a child can have only one mother .

So in main I read(the file.txt witch contains the name, age and id for mother and name and age fro child)and parse it Main:

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class Main5 {
    public static void main(String[] args) throws IOException {
        List<Mother> mothers = mother();
        System.out.println(mothers);

        List<Child> child = child();
        System.out.println(child);
    }

    public static List<Mother> mother() throws IOException {
        List<Mother> mothers = new ArrayList<>();
        BufferedReader bufferedReader = new BufferedReader(new FileReader("mom.txt"));
        String line;
        while ((line = bufferedReader.readLine()) != null) {
            String[] s = line.split("\\s+");
            mothers.add(new Mother(Integer.parseInt(s[0]), s[1], Integer.parseInt(s[2])));
        }
        bufferedReader.close();
        return mothers;
    }
    public static List<Child> child() throws IOException {
        List<Child> childs = new ArrayList<>();
        BufferedReader bufferedReader = new BufferedReader(new FileReader("child.txt"));
        String line;
        while ((line = bufferedReader.readLine()) != null) {
            String[] s = line.split("\\s+");
            childs.add(new Child(s[0], Integer.parseInt(s[1])));
        }
        bufferedReader.close();
        return childs;
    }
}

Is there somoane that can give me an example of how I should to it or where I should start?

Answer 1

You can maintain a list of child on mother. By doing this a mother object will have many child and maintain a mother class ref. in child. will allow you to have a child only one mother.

Example:

class Mother{

    private List<Child> childList = new ArrayList<>();

    ....................................................
    ....................................................
}

class Child{

    private Mother mother;

    ....................................................
    ....................................................
}

BTW you should post what you have tried so far. Try reading about java collection.