How to add JTable in JPanel with null layout?

I want to add JTable into JPanel whose layout is null. JPanel contains other components. I have to add JTable at proper position.

Nested/Combination Layout Example

The Java Tutorial has comprehensive information on using layout managers. See the Laying Out Components Within a Container lesson for further details.

One aspect of layouts that is not covered well by the tutorial is that of nested layouts, putting one layout inside another to get complex effects.

The following code puts a variety of components into a frame to demonstrate how to use nested layouts. All the layouts that are explicitly set are shown as a titled-border for the panel on which they are used.

Notable aspects of the code are:

• There is a combo-box to change PLAF (Pluggable Look and Feel) at run-time.
• The GUI is expandable to the user's need.
• The image in the bottom of the split-pane is centered in the scroll-pane.
• The label instances on the left are dynamically added using the button.

Nimbus PLAF

NestedLayoutExample.java

import java.awt.*;
import java.awt.image.BufferedImage;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.*;
import javax.swing.table.DefaultTableModel;
import javax.swing.border.TitledBorder;

/** A short example of a nested layout that can change PLAF at runtime.
The TitledBorder of each JPanel shows the layouts explicitly set.
@author Andrew Thompson
@version 2011-04-12 */
class NestedLayoutExample {

    public static void main(String[] args) {

        Runnable r = new Runnable() {

            public void run() {
                final JFrame frame = new JFrame("Nested Layout Example");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

                final JPanel gui = new JPanel(new BorderLayout(5,5));
                gui.setBorder( new TitledBorder("BorderLayout(5,5)") );

                //JToolBar tb = new JToolBar();
                JPanel plafComponents = new JPanel(
                    new FlowLayout(FlowLayout.RIGHT, 3,3));
                plafComponents.setBorder(
                    new TitledBorder("FlowLayout(FlowLayout.RIGHT, 3,3)") );

                final UIManager.LookAndFeelInfo[] plafInfos =
                    UIManager.getInstalledLookAndFeels();
                String[] plafNames = new String[plafInfos.length];
                for (int ii=0; ii<plafInfos.length; ii++) {
                    plafNames[ii] = plafInfos[ii].getName();
                }
                final JComboBox plafChooser = new JComboBox(plafNames);
                plafComponents.add(plafChooser);

                final JCheckBox pack = new JCheckBox("Pack on PLAF change", true);
                plafComponents.add(pack);

                plafChooser.addActionListener( new ActionListener(){
                    public void actionPerformed(ActionEvent ae) {
                        int index = plafChooser.getSelectedIndex();
                        try {
                            UIManager.setLookAndFeel(
                                plafInfos[index].getClassName() );
                            SwingUtilities.updateComponentTreeUI(frame);
                            if (pack.isSelected()) {
                                frame.pack();
                                frame.setMinimumSize(frame.getSize());
                            }
                        } catch(Exception e) {
                            e.printStackTrace();
                        }
                    }
                } );

                gui.add(plafComponents, BorderLayout.NORTH);

                JPanel dynamicLabels = new JPanel(new BorderLayout(4,4));
                dynamicLabels.setBorder(
                    new TitledBorder("BorderLayout(4,4)") );
                gui.add(dynamicLabels, BorderLayout.WEST);

                final JPanel labels = new JPanel(new GridLayout(0,2,3,3));
                labels.setBorder(
                    new TitledBorder("GridLayout(0,2,3,3)") );

                JButton addNew = new JButton("Add Another Label");
                dynamicLabels.add( addNew, BorderLayout.NORTH );
                addNew.addActionListener( new ActionListener(){

                    private int labelCount = 0;

                    public void actionPerformed(ActionEvent ae) {
                        labels.add( new JLabel("Label " + ++labelCount) );
                        frame.validate();
                    }
                } );

                dynamicLabels.add( new JScrollPane(labels), BorderLayout.CENTER );

                String[] header = {"Name", "Value"};
                String[] a = new String[0];
                String[] names = System.getProperties().
                    stringPropertyNames().toArray(a);
                String[][] data = new String[names.length][2];
                for (int ii=0; ii<names.length; ii++) {
                    data[ii][0] = names[ii];
                    data[ii][1] = System.getProperty(names[ii]);
                }
                DefaultTableModel model = new DefaultTableModel(data, header);
                JTable table = new JTable(model);
                try {
                    // 1.6+
                    table.setAutoCreateRowSorter(true);
                } catch(Exception continuewithNoSort) {
                }
                JScrollPane tableScroll = new JScrollPane(table);
                Dimension tablePreferred = tableScroll.getPreferredSize();
                tableScroll.setPreferredSize(
                    new Dimension(tablePreferred.width, tablePreferred.height/3) );

                JPanel imagePanel = new JPanel(new GridBagLayout());
                imagePanel.setBorder(
                    new TitledBorder("GridBagLayout()") );

                BufferedImage bi = new BufferedImage(
                    200,200,BufferedImage.TYPE_INT_ARGB);
                Graphics2D g = bi.createGraphics();
                GradientPaint gp = new GradientPaint(
                    20f,20f,Color.red, 180f,180f,Color.yellow);
                g.setPaint(gp);
                g.fillRect(0,0,200,200);
                ImageIcon ii = new ImageIcon(bi);
                JLabel imageLabel = new JLabel(ii);
                imagePanel.add( imageLabel, null );

                JSplitPane splitPane = new JSplitPane(
                    JSplitPane.VERTICAL_SPLIT,
                    tableScroll,
                    new JScrollPane(imagePanel));
                gui.add( splitPane, BorderLayout.CENTER );

                frame.setContentPane(gui);

                frame.pack();

                frame.setLocationRelativeTo(null);
                try {
                    // 1.6+
                    frame.setLocationByPlatform(true);
                    frame.setMinimumSize(frame.getSize());
                } catch(Throwable ignoreAndContinue) {
                }

                frame.setVisible(true);
            }
        };
        SwingUtilities.invokeLater(r);
    }
}

Other Screen Shots

Windows PLAF

Mac OS X Aqua PLAF

Ubuntu GTK+ PLAF

Don't use a null layout. Learn to use LayoutManagers:

http://download.oracle.com/javase/tutorial/uiswing/layout/using.html

LayoutManagers allow you to properly handle things window resizing or dynamic component counts. They might seem intimidating at first, but they are worth the effort to learn.