AppFrame.java

import javax.swing.*;
import java.awt.*;
public class AppFrame extends JFrame{
  public AppFrame(){
    setBounds(10,10,400,400);
    CodePane pane=new CodePane();
    getContentPane().setLayout(new BorderLayout());
    getContentPane().add(new JScrollPane(pane),BorderLayout.CENTER);
    setVisible(true);
  }
  public static void main(String[] args) {
    new AppFrame();
  }
}