Question

I am trying to resize the widths of the columns in a JTable.
I would need to resize them when the program is running to see the full column header names.
I want to resize table of database showing in swing frame.

I have tried

table.setAutoResizeMode(JTable.AUTO_RESIZE_ALL_COLUMNS)

But I didn’t get the desired output because when I use this I have a horizontal scrollbar to scroll to the columns that are off screen. But I want the size of the whole table to become approximately equal to the size of frame.

How can I make the columns as wide as they need to be to display all the text?

Answer 1

But I want the size of the whole table to become approximately equal to the size of frame.

JTable table = ...;
JFrame frame = ...;
JPanel contentPane = new JPanel( new BorderLayout() );
contentPane.add( new JScrollPane( table ), BorderLayout.CENTER );
frame.setContentPane( contentPane );

How can I make the columns as wide as they need to be to display all the text?

Unfortunately, the maximum width of the JTable will be limited to the size of the JFrame, and there is no mechanism to push from your JTable the desired width to the JFrame when your JTable is contained in a JScrollPane.

What you could do is try to give your JScrollPane the correct width. I haven’t tried this, but I suspect that giving your scrollpane the same width as the preferred width of your table (when autoresize is on) should solve this (+ perhaps some extra width for the vertical scrollbar). Note however that this will only work if you allow your JFrame in which the JScrollPane is contained to grow in width as well.