test.java:

package test;

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

public class test extends JFrame {
  private Canvas c = new Canvas();

  public test() {
    try {
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }
  }
  public static void main(String[] args) {
    test test1 = new test();
    test1.setVisible(true);
  }
  private void jbInit() throws Exception {
    this.setSize(new Dimension( 200 ,  200 ));
    this.getContentPane().add(c);
  }

}


Canvas.java:

package test;

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

public class Canvas extends JPanel {
  BorderLayout borderLayout1 = new BorderLayout();

  public Canvas() {
    try {
      jbInit();
    }
    catch(Exception ex) {
      ex.printStackTrace();
    }
  }

  public void paint(Graphics g) {
    super.paint(g);
    g.drawOval( 100 , 100 , 20 , 50 );
  }

  void jbInit() throws Exception {
    this.setLayout(borderLayout1);
  }
}