JTable Won't Show On JPanel

Question

Hi I have created a Jtable and can get it to show on my frame yet not on the JPanel I have ontop of my JFrame. I can't seem to change

import java.awt.;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.;
import java.util.ArrayList;
import java.util.Comparator;
import javax.swing.;
import javax.swing.table.;


public class Main
{
    DefaultTableModel table_model;
    String[][] addressData = new String[10][5];
    JPanel panel;
    JFrame frame;
    JButton loadData;
    int count,index,row =0;
    String thisLine;
    ArrayList People = new ArrayList();

public Main()
{
    //Creating JFrame and setting properties
    frame = new JFrame();
    frame.setResizable(false);
    frame.setTitle("Address Book");
    frame.setSize(800,600);
    frame.setDefaultCloseOperation(frame.EXIT_ON_CLOSE);

    //Creating JPanel and setting properties
    panel = new JPanel();
    panel.setLayout(null);
    panel.setBackground(new Color(77,81,84));

    //Setting the table and Scroll Bars
    this.table_model = new DefaultTableModel(addressData, new String[]{"First Name", "Surname", "Home Number", "Mobile Number", "Address", "Postcode"});
    JTable table = new JTable(this.table_model);
    table.setBounds(130, 40, 200, 200);
    panel.add(new JScrollPane(table, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS));

    //Load Data button, reading file in and adding data to ArrayList then Array of Arrays
    loadData = new JButton("Load File");
    loadData.setBounds(10, 10, 100, 20);
    loadData.addActionListener(new ActionListener()
    {
        public void actionPerformed(ActionEvent e)
        {
            try
            {
                BufferedReader reader = new BufferedReader(new FileReader("file/address.buab"));
                while ((thisLine = reader.readLine()) !=null)
                {
                    if (row >= 4)
                    {
                        index++;
                        row = 0;
                        People.add(thisLine);
                        addressData[index][row] = People.get(count);
                        count++;
                        row++;
                    }
                    else
                    {
                    People.add(thisLine);
                    addressData[index][row] = People.get(count);
                    count++;
                    row++;
                    }
                }
                reader.close();
            }
            catch (IOException ex)
            {
                System.err.println("Input Exception, Check address.buab File");
            }
        }
    });
    panel.add(loadData);

    //Auto sort on table fields
    TableRowSorter<TableModel> sorter = new TableRowSorter<TableModel>(this.table_model);
    sorter.setComparator(1, new Comparator<Integer>()
    {
        public int compare(Integer o1, Integer o2)
        {
            return o1.compareTo(o2);
        }

        public boolean equals(Object obj)
        {
            return obj.equals(this);
        }
    });

    table.setRowSorter(sorter);

    frame.getContentPane().add(panel);
    frame.setVisible(true);
}

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

}

Any ideas on how I might go about setting the table visible ontop of my JPanel

Answer 1

You need to create your JPanel with a specific layout manager and then add components (the JTable and JButton ) with appropriate constraints to cause them to appear in the correct area of the panel. Currently you are setting the panel's layout manager to null , which is almost certainly incorrect. You may want to check out the Using Layout Managers tutorial.

One simple layout manager to consider is BorderLayout . For example:

// Create JPanel with BorderLayout layout manager.
JPanel panel = new JPanel(new BorderLayout());

// Add JTable to panel center.  This component will expand
// to take up available space.
panel.add(myTableScrollPane, BorderLayout.CENTER);

// Add button to the bottom of the panel.
panel.add(myButton, BorderLayout.SOUTH);

Answer 2

A wild guess:

 panel.setLayout(null);

Try this instead:

 panel.setLayout(new BorderLayout());

And later:

 panel.add(loadData, BorderLayout.SOUTH) // e.g. for the button

 // e.g. for the table
 panel.add(new JScrollPane(table, .....)), BorderLayout.CENTER)