How to make JTable both AutoResize and horizontall scrollable?

I am putting a JTable into a JScrollPane

But When I set JTable Auto Resizeable, then it won't have horizontal scroll bar.

if I set AUTO_RESIZE_OFF, then the Jtable won't fill the width of its container when the 开发者_高级运维column width is not big enough.

So how can I do this:

1. when the table is not wide enough, expand to fill its container width
2. when the table is wide enough, make it scrollable.

Thanks

You need to customize the behaviour of the Scrollable interface.

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;

public class TableHorizontal extends JFrame
{
    public TableHorizontal()
    {
        final JTable table = new JTable(10, 5)
        {
            public boolean getScrollableTracksViewportWidth()
            {
                return getPreferredSize().width < getParent().getWidth();
            }
        };
        table.setAutoResizeMode( JTable.AUTO_RESIZE_OFF );
        final JScrollPane scrollPane = new JScrollPane( table );
        getContentPane().add( scrollPane );
    }

    public static void main(String[] args)
    {
        TableHorizontal frame = new TableHorizontal();
        frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
        frame.pack();
        frame.setSize(400, 300);
        frame.setVisible(true);
    }
}

The above code basically sizes the component at its preferred size or the viewport size, whichever is greater.

If for some reason customising JTable is not an option (e.g. it might be created in third-party code), you can achieve the same result by setting it to toggle between two different JTable AUTO_RESIZE modes whenever the containing viewport is resized, e.g.:

jTable.getParent().addComponentListener(new ComponentAdapter() {
    @Override
    public void componentResized(final ComponentEvent e) {
        if (jTable.getPreferredSize().width < jTable.getParent().getWidth()) {
            jTable.setAutoResizeMode(JTable.AUTO_RESIZE_ALL_COLUMNS);
        } else {
            jTable.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
        }
    }
});

I found that all that is needed is to include

  table = new JTable(model);
  // this enables horizontal scroll bar
  table.setAutoResizeMode( JTable.AUTO_RESIZE_OFF );    

and then when the required viewport width and height have been calculated, include

  frame.getContentPane().add(new JScrollPane(table))
  table.setPreferredScrollableViewportSize(new Dimension(width,height));

If you set the Layout of its container to BorderLayout with a BorderLayout.CENTER layout constraint, then the JTable will auto resize to fit its container.

If you want to make a component scrollable, you can wrap the JTable with a JScrollPane.

setLayout(new BorderLayout());
add(new JScrollPane(new JTable()), BorderLayout.CENTER);