JPanel not appearing on JFrame

Question

I have created a basic UI for my Dice Game. But my panels are not appearing in the JFrame. Please help me fix it. I'm new to Java Swing.

package View;

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

/**
 *
 * @author Akila
 */
public class MainUi extends JFrame {
    public MainUi(){
        initComponents();
    }

    public void initComponents() {
        setTitle("Dice Game");
        setVisible(true);
        setSize(500, 400);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setResizable(true);
        Container c = getContentPane();

//        *******First Row Components*******
        JPanel firstRow = new JPanel();

        JLabel pc = new JLabel("PC Score");
        JLabel user = new JLabel("User Score");
        JLabel pcScore = new JLabel();
        JLabel userScore = new JLabel();


//        *******Second Row Components*******
        JPanel secondRow = new JPanel();

        JLabel pcFirstDice = new JLabel();
        JLabel pcSecondDice = new JLabel();
        JLabel pcThirdDice = new JLabel();
        JLabel pcFourthDice = new JLabel();
        JLabel pcFifthDice = new JLabel();

        JCheckBox checkPcFirstDice = new JCheckBox();
        JCheckBox checkPcSecondDice = new JCheckBox();
        JCheckBox checkPcThirdDice = new JCheckBox();
        JCheckBox checkPcFourthDice = new JCheckBox();
        JCheckBox checkPcFifthDice = new JCheckBox();

//        *******Third Row Components*******
        JPanel thirdRow = new JPanel();

        JLabel userFirstDice = new JLabel();
        JLabel userSecondDice = new JLabel();
        JLabel userThirdDice = new JLabel();
        JLabel userFourthDice = new JLabel();
        JLabel userFifthDice = new JLabel();

        JCheckBox checkUserFirstDice = new JCheckBox();
        JCheckBox checkUserSecondDice = new JCheckBox();
        JCheckBox checkUserThirdDice = new JCheckBox();
        JCheckBox checkUserFourthDice = new JCheckBox();
        JCheckBox checkUserFifthDice = new JCheckBox();

//        *******Fourth Row Components*******
        JPanel fourthRow = new JPanel();

        JButton throwDice = new JButton("Throw");
        JButton updateScore = new JButton("Update Score");

//        *******First Row GridBag Layout*******
        firstRow.setSize(400, 100);
        firstRow.setLayout(new GridBagLayout());
        GridBagConstraints first = new GridBagConstraints();
        first.weightx = 1;
        first.weighty = 0.25;

//        Add First Row Components
        first.gridx = 1;
        first.gridy = 0;
        firstRow.add(pcScore,first);
        c.add(firstRow,BorderLayout.NORTH);
    }
}

Answer 1

The problem is you are not adding any components to JPanelyou just create the components and add empty panel to Container.

Here is a code snippet example of adding first row components to JPanel:

//        *******First Row Components*******
    JPanel firstRow = new JPanel();

    JLabel pc = new JLabel("PC Score");
    JLabel user = new JLabel("User Score");
    JLabel pcScore = new JLabel();
    JLabel userScore = new JLabel();

    firstRow.add(pc);
    firstRow.add(user);
    firstRow.add(pcScore);
    firstRow.add(userScore);

You might also want to add all other panel rows to Container since you are only adding first row to it.

Answer 2

You got two problems over here:

1. You forgot to add your rows to your Frame:

       c.add(secondRow);
       c.add(thirdRow);
       c.add(fourthRow)
       c.add(firstRow);
   

2. You Forgot to add your content to your Rows(example for row one):

   //        *******First Row Components*******
   JPanel firstRow = new JPanel();
   
   JLabel pc = new JLabel("PC Score");
   JLabel user = new JLabel("User Score");
   JLabel pcScore = new JLabel();
   JLabel userScore = new JLabel();
   
   firstRow.add(pc);
   firstRow.add(user);
   firstRow.add(pcScore);
   firstRow.add(userScore);
   

Hope that helps!