Adding a JPanel into a JFrame - swing

Question

I know this sounds like an easy question, but I am making a simple text adventure with buttons and such, and I cant figure out how to add my Jpanel into my JFrame. My JPanel has a bunch of buttons and graphics and stuff if that makes a difference. I have provided the code below. frame panel=new frame(); is the other class which extends JPanel. I know its confusing that its called "frame", its because I used to have it extend JFrame. Anyways my code doesnt produce the buttons, graphics etc, from the other class like it should. Thanks,
package sonomaroller;
import javax.swing.*;
import java.awt.*;
import static javax.swing.JFrame.*;
public class SonomaRoller extends JFrame {
public static Dimension size = new Dimension(550,550); //Dimension of Frame
public static String title = "Sonoma Roller v0.00" ;
public SonomaRoller(){
setTitle(title);
setSize(size);
setResizable(false);
setLocationRelativeTo(null); // null centers window on screen
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
System.out.println("hello?");
//setLayout(null);
setVisible(true);
}
public static void main(String[] args) {
SonomaRoller object1=new SonomaRoller();
frame panel=new frame();
}
}

Answer 1

Try
SonomaRoller object1=new SonomaRoller();
frame panel=new frame();
object1.getContentPane().add(panel);
or just simply
object1.add(panel);
From: JFrame#getContentPane()
and Container#add(Component)
Here's some code that works if it helps:
import java.awt.*;
import javax.swing.*;
public class MyFrame extends JFrame {
public MyFrame() {
add(new MyPanel());
setSize(640, 480);
}
public static void main(String[] args) throws Exception {
SwingUtilities.invokeAndWait(new Runnable() {
#Override public void run() {
new MyFrame().setVisible(true);
}
});
}
}
class MyPanel extends JPanel {
#Override protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.fillOval(20, 20, 80, 80);
}
}

Answer 2

maybe like this...?
package sonomaroller;
import javax.swing.*;
import java.awt.*;
import javax.swing.JFrame.*;
public class SonomaRoller extends JFrame {
public static Dimension size = new Dimension(550,550); //Dimension of Frame
public static String title = "Sonoma Roller v0.00" ;
public SonomaRoller(){
setTitle(title);
setSize(size);
setResizable(false);
setLocationRelativeTo(null); // null centers window on screen
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
System.out.println("hello?");
//setLayout(null);
setVisible(true);
frame panel=new frame();
setContentPane(panel);
}
public static void main(String[] args) {
SonomaRoller object1=new SonomaRoller();
}
}

Answer 3

This is how I normally do it:
public class SonomaRoller extends JFrame {
public SonomaRoller(){
setLayout(new BorderLayout(0, 0));
JPanel newPanel = new JPanel();
getContentPane().add(newPanel);
}
}

Answer 4

this is the problem :
frame panel=new frame();
put this line instead of above code :
Frame frame = new Frame();
Panel panel = new Panel();
frame.add(panel);