java screen not showing

[SVENeRGy]

you create your objects here:

public class EncMain extends JFrame
{
private JLabel imageIcon;
private JComboBox box1;
private JButton button1;
private JLabel label1;
private JLabel label2;
private JTextField field1;

And later you create them again:

JLabel label1 = new JLabel();
JLabel label2 = new JLabel();
JButton button1 = new JButton();
JTextField text1 = new JTextField();
JComboBox box1 = new JComboBox();

you should change that last in:

this.label1 = new JLabel();
this.label2 = new JLabel();
this.button1 = new JButton();
this.field1 = new JTextField();
this.box1 = new JComboBox();