Drawing oval

Question

Here i draw net consist of 6 rows and 7 columns , then i want to draw oval in the top of the net . I think i wrote correct code but the oval not appear .
I want to know why ??
my simple code :
import java.awt.BorderLayout;
import java.awt.Dimension;
import javax.swing.JFrame;
public class TestNet extends JFrame {
    private DrawingNet drawingNet;
    public TestNet() {
        drawingNet = new DrawingNet();
        getContentPane().add(drawingNet, BorderLayout.CENTER);
    public static void main(String[] args) {
        TestNet testNet = new TestNet();
        testNet.setDefaultCloseOperation(TestNet.EXIT_ON_CLOSE);
        testNet.setSize(new Dimension(600, 300));
        testNet.setLocationRelativeTo(null);
        testNet.setVisible(true);
        testNet.setExtendedState(MAXIMIZED_BOTH);
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JPanel;
class DrawingNet extends JPanel {
    private static final int ROW = 6, COL = 7;
    private int X_START, Y_START, DISTANCE_Y, DISTANCE_X;
    private int x_OVAL = 348, y_OVAL = 17, OVAL_Width = 83, OVAL_HEIGHT = 83;
    public DrawingNet() {
        MyOval myOval = new MyOval();
        myOval.setOval_X(x_OVAL);
        myOval.setOval_Y(y_OVAL);
        myOval.setOVAL_WIDTH(OVAL_Width);
        myOval.setOVAL_HEIGHT(OVAL_HEIGHT);
        add(myOval);
    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2d = (Graphics2D) g;
        drawingNet(g2d);
    private void drawingNet(Graphics2D g2d) {
        X_START = 97;
        Y_START = 100;
        DISTANCE_Y = 0;
        DISTANCE_X = 0;
        g2d.setColor(Color.BLACK);
        for (int r = 0; r < ROW; r++) {
            g2d.drawLine(X_START, Y_START + DISTANCE_Y, X_START * COL, Y_START + DISTANCE_Y);
            DISTANCE_Y += 83;
        for (int c = 0; c <= COL; c++) {
            g2d.drawLine(X_START + DISTANCE_X, Y_START, X_START + DISTANCE_X, (Y_START * ROW) - 83);
            DISTANCE_X += 83;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JPanel;
class MyOval extends JPanel {
    private int oval_X, oval_Y;
    private int OVAL_WIDTH, OVAL_HEIGHT;
    public MyOval() {
    public void setOVAL_HEIGHT(int OVAL_HEIGHT) {
        this.OVAL_HEIGHT = OVAL_HEIGHT;
    public void setOVAL_WIDTH(int OVAL_WIDTH) {
        this.OVAL_WIDTH = OVAL_WIDTH;
    public void setOval_X(int oval_X) {
        this.oval_X = oval_X;
    public void setOval_Y(int oval_Y) {
        this.oval_Y = oval_Y;
    public int getOVAL_HEIGHT() {
        return OVAL_HEIGHT;
    public int getOVAL_WIDTH() {
        return OVAL_WIDTH;
    public int getOval_X() {
        return oval_X;
    public int getOval_Y() {
        return oval_Y;
    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2d = (Graphics2D) g;
        g2d.setColor(Color.BLUE);
        g2d.fillOval(getOval_X(), getOval_Y(), getOVAL_WIDTH(), getOVAL_HEIGHT());
}Thanks

Answer 1

ok, i but in MyOval button to test if it will appear or no and i add someLayouts like this but the buttont also not appear . why ??
see the updated code :
import java.awt.BorderLayout;
import java.awt.Dimension;
import javax.swing.JFrame;
public class TestNet extends JFrame {
    private DrawingNet drawingNet;
    public TestNet() {
        drawingNet = new DrawingNet();
        drawingNet.setLayout(new BorderLayout());
        getContentPane().add(drawingNet, BorderLayout.CENTER);
    public static void main(String[] args) {
        TestNet testNet = new TestNet();
        testNet.setDefaultCloseOperation(TestNet.EXIT_ON_CLOSE);
        testNet.setSize(new Dimension(600, 300));
        testNet.setLocationRelativeTo(null);
        testNet.setVisible(true);
        testNet.setExtendedState(MAXIMIZED_BOTH);
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JPanel;
class DrawingNet extends JPanel {
    private static final int ROW = 6, COL = 7;
    private int X_START, Y_START, DISTANCE_Y, DISTANCE_X;
    private int x_OVAL = 348, y_OVAL = 17, OVAL_Width = 83, OVAL_HEIGHT = 83;
    public DrawingNet() {
        MyOval myOval = new MyOval();
        myOval.setLayout(new BorderLayout());
        myOval.setOval_X(x_OVAL);
        myOval.setOval_Y(y_OVAL);
        myOval.setOVAL_WIDTH(OVAL_Width);
        myOval.setOVAL_HEIGHT(OVAL_HEIGHT);
        add(myOval,BorderLayout.NORTH);
    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2d = (Graphics2D) g;
        drawingNet(g2d);
    private void drawingNet(Graphics2D g2d) {
        X_START = 97;
        Y_START = 100;
        DISTANCE_Y = 0;
        DISTANCE_X = 0;
        g2d.setColor(Color.BLACK);
        for (int r = 0; r < ROW; r++) {
            g2d.drawLine(X_START, Y_START + DISTANCE_Y, X_START * COL, Y_START + DISTANCE_Y);
            DISTANCE_Y += 83;
        for (int c = 0; c <= COL; c++) {
            g2d.drawLine(X_START + DISTANCE_X, Y_START, X_START + DISTANCE_X, (Y_START * ROW) - 83);
            DISTANCE_X += 83;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
class MyOval extends JPanel {
    private int oval_X, oval_Y;
    private int OVAL_WIDTH, OVAL_HEIGHT;
    public MyOval() {
        JButton button = new JButton("OVAL");
        button.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                JOptionPane.showMessageDialog(null, "HIIIIIIIIIIII");
        add(button, BorderLayout.NORTH);
    public void setOVAL_HEIGHT(int OVAL_HEIGHT) {
        this.OVAL_HEIGHT = OVAL_HEIGHT;
    public void setOVAL_WIDTH(int OVAL_WIDTH) {
        this.OVAL_WIDTH = OVAL_WIDTH;
    public void setOval_X(int oval_X) {
        this.oval_X = oval_X;
    public void setOval_Y(int oval_Y) {
        this.oval_Y = oval_Y;
    public int getOVAL_HEIGHT() {
        return OVAL_HEIGHT;
    public int getOVAL_WIDTH() {
        return OVAL_WIDTH;
    public int getOval_X() {
        return oval_X;
    public int getOval_Y() {
        return oval_Y;
    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2d = (Graphics2D) g;
        g2d.setColor(Color.BLUE);
        g2d.fillOval(getOval_X(), getOval_Y(), getOVAL_WIDTH(), getOVAL_HEIGHT());
}