Getting my GUI to create an instance from a class and pull that information down into a text area

Question

The goal of this project is simply to enter some text, press a button, and have my GUI create an instance of the "Dog" class in the text area. However, when I press my button, it always prints: "Dog@2a4c6a7d" or some other seemingly random combination of numbers and letters. Any help with this issue would be greatly appreciated. Thanks!

Correct and functioning code below:

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

class Dog {
    private String name;
    private String breed;
    private String age;

    public Dog(String name, String breed, String age) {
        this.name = name;
        this.breed = breed;
        this.age = age;
    }

    public String setDogName(String name) {
        this.name = name;
        return name;
    }

    public String setDogBreed(String breed) {
        this.breed = breed;
        return breed;
    }

    public String SetDogAge(String age) {
        this.age = age;
        return age;
    }

    public String toString() {
        return ("Name:  " + this.name + "  Breed:  " + this.breed + "  Age:  " + this.age);
    }

}

public class LabThree extends JFrame implements ActionListener {
    public LabThree() {
        setLayout(new GridLayout(8, 3));

        // Creates TextFields, TextAreas, and the button
        name = new JTextField();
        breed = new JTextField();
        age = new JTextField();
        JButton jbtGenerate = new JButton("Generate Dog");
        echoDog = new JTextArea();

        // Adds TextFields, TextAreas, and the button
        add(new JLabel("Name:"));
        add(name);
        add(new JLabel("Breed:"));
        add(breed);
        add(new JLabel("Age:"));
        add(age);
        add(jbtGenerate);
        jbtGenerate.addActionListener(this);
        add(echoDog);
        echoDog.setEditable(false);

    }

    // Top TextFields
    private JTextField name;
    private JTextField breed;
    private JTextField age;

    // Bottom(echoed) TextArea
    private JTextArea echoDog;

    public void actionPerformed(ActionEvent a) {
        Dog dog1 = new Dog(name.getText(), breed.getText(), age.getText());
        echoDog.setText(dog1.toString());
    }

    public static void main(String[] args) {
        LabThree frame = new LabThree();
        frame.setTitle("Dog Generator");
        frame.setSize(500, 400);
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
        frame.setVisible(true);

    }

}

Answer 1

You need to override the toString() function in your Dog class. Something like this:

public String toString()
{
    return this.name + this.breed + this.age;
}

A little explanation:

You Dog class by default inherits from Object. In object, there is a toString() already declared that returns getClass().getName() + '@' + Integer.toHexString(hashCode()). This is what you are seeing when you say Dog@2a4c6a7d. It is the name of the class and then the hash code of your class.

When you add the toString() function like above to your Dog class, your new toString() gets called instead. This is a key concept of object oriented programming.