How i create object of this class

Question

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.print.PrinterException;
import java.text.MessageFormat;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
public class vendor extends JDialog // probably best to use a JDialog, not a JFrame here
// make some instance variables
private String rows[][] =
{"A", "a"},
{"B", "b"},
{"E", "e"}
private String headers[] =
"Upper", "Lower"
private JTable table = new JTable(rows, headers);
// here's the constructor.
public MainClass(JFrame frame, String title, boolean modal)
super(frame, title, modal);
//frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JScrollPane scrollPane = new JScrollPane(table);
add(scrollPane, BorderLayout.CENTER);
JButton button = new JButton("Print");
ActionListener printAction = new ActionListener()
public void actionPerformed(ActionEvent e)
printActionPerformed(e);
button.addActionListener(printAction);
add(button, BorderLayout.SOUTH);
setPreferredSize(new Dimension(300, 150));
//frame.setSize(300, 150);
//frame.setVisible(true);
private void printActionPerformed(ActionEvent e)
try
MessageFormat headerFormat = new MessageFormat("Page {0}");
MessageFormat footerFormat = new MessageFormat("- {0} -");
table.print(JTable.PrintMode.FIT_WIDTH, headerFormat,
footerFormat);
catch (PrinterException pe)
System.err.println("Error printing: " + pe.getMessage());
     public static void main(String x[])
{new vendor();}
}

Answer 1

You have to call it from a JFrame or other root container:
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class UseDialog extends JPanel
    private JFrame frame = null;
    private MainClass myDialog = null;
    public UseDialog(JFrame frame)
        setPreferredSize(new Dimension(300, 200));
        this.frame = frame;
        JButton showDialogBtn = new JButton("Show Dialog");
        add(showDialogBtn);
        showDialogBtn.addActionListener(new ActionListener()
            public void actionPerformed(ActionEvent e)
                showDialogBtnAction(e);
    private void showDialogBtnAction(ActionEvent e)
        //*********** here is where it is called **************
        myDialog = new MainClass(frame, "My Dialog", true);
        myDialog.pack();
        myDialog.setVisible(true);
    private static void createAndShowGUI()
        JFrame frame = new JFrame("UseDialog Application");
        frame.getContentPane().add(new UseDialog(frame));
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    public static void main(String[] args)
        SwingUtilities.invokeLater(new Runnable()
            public void run()
                createAndShowGUI();
}Also, when posting your code, please use code tags so that your code will be well-formatted and readable. To do this, place the tag [code] at the top of your block of code and the tag [/code] at the bottom, like so:
[code]
  // your code block goes here.
[/code]good luck