Connecting 2 different programs in Java (each one has its main method)
<p>I have created 2 programs (Background and NrLojtareve) using Java GUI where each one of them creates a step of a game.  Each program has its own main method.</p>

<p>All I want to do is after executing the first program (NrLojtareve) which includes 4 radio buttons to display the other page, I created with the other program(Background).</p>

<p>So going from the first step of the game to the second.  So the handler of NrLojtareve class to call the Background class.</p>

<p>Can anyone show me how to call the second program from the first or how to display the second GUI after selecting a radio button from the first program?</p>

<p><br/>
Here is the code.</p>

<p><strong>Nrlojtareve.java</strong></p>

<pre><code>import java.awt.*;
import java.awt.event.*;
import javax.swing.event.*;
import javax.swing.*;

public class Nrlojtareve extends JFrame {

    private JRadioButton a;
    private JRadioButton b;
    private JRadioButton c;
    private JRadioButton d;
    private ButtonGroup group ;
    private JLabel e;

    public Nrlojtareve() {
        setLayout(new FlowLayout());
        a=new JRadioButton("1");
        b=new JRadioButton("2");
        c=new JRadioButton("3");
        d=new JRadioButton("4");
        e=new JLabel("Choose the number of players!");
        add(a);
        add(b);
        add(c);
        add(d);
        add(e);
        group = new ButtonGroup();
        group.add(a);
        group.add(b);
        group.add(c);
        group.add(d);

        thehandler hand = new thehandler();
        a.addItemListener(hand);
        b.addItemListener(hand);
        c.addItemListener(hand);
        d.addItemListener(hand);
    }

    private class thehandler implements ItemListener {
        public void itemStateChanged(ItemEvent event) {

        }
    }

    public static void main(String[] args) {

        Nrlojtareve elda = new Nrlojtareve();
        elda.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        elda.setSize(300,400);
        elda.setVisible(true);
    }

}
</code></pre>

<p><br/>
<strong>Back.java</strong></p>

<pre><code>import java.awt.*;
import java.awt.event.*;
import javax.swing.event.*;
import javax.swing.*;
import java.util.Random;

public class Back extends JFrame {

private Container pane;
    public Back() {
        super("title");
        setLayout(null);

        Icon i=new ImageIcon(getClass().getResource("1.png"));
        pane=new Container();

        //konstruktori i handler merr nje instance te Background
        thehandler hand = new thehandler();

    }

     private class thehandler implements ActionListener {

         public void actionPerformed(ActionEvent event) {

         }
    }
    public static void main(String[] args) {

         Back  d = new Back() ;

         d.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         d.getContentPane().setBackground(Color.GREEN);
         d.setSize(700,500);

         d.setVisible(true);    
    }
}
</code></pre>