Java: JFrame -> JPanel

//Main class calling JPanel from JFrame

publicc class Main{
    public static void main(String arg[]{

    //--the beginning of event--
    private void open_ViewActionPerformed(java.awt.event.ActionEvent evt) {
    EventQueue.invokeLater(new Runnable() {
            public void run() {
                JFrame frame = new JFrame();
                frame.setContentPane(new View());  // <--calling the constructor of View class
                frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
                frame.pack();
                frame.setVisible(true);
            }
        });
    //--the end of event--

    }
}

//View class with JPanel edited by GUI Designer

class View extends JPanel {
    public View() {     // <-- the consructor of View class
    initComponents();
    }
    private void initComponents(){  // <-- coded by GUI Designer
    }
}