Thread: problem with BoxLayout and JTextField

I have a weird problem with laying out some JTextFields.

This code works right:

                JPanel setbuttonpanel = new JPanel();
		setbuttonpanel.setLayout( new BoxLayout(setbuttonpanel, BoxLayout.LINE_AXIS) );		
 		inputfield = new JTextField(20);
 		setbuttonpanel.add(inputfield);
 		setbuttonpanel.add( Box.createRigidArea( new Dimension(offset, 0) ) );
		...
		setbutton = new JButton(new SetAction("Set"));
		setbuttonpanel.add(setbutton);
		panel.add(setbuttonpanel);

This code does not: (it blows up the textfield's height)

                JPanel inputpanel = new JPanel();
		inputpanel.setLayout( new BoxLayout(inputpanel,BoxLayout.LINE_AXIS)) ;
		seedinput = new JTextField(5);
		amountinput = new JTextField(5);				
		inputpanel.add(seedinput);
		inputpanel.add(amountinput);
		panel.add(inputpanel);

How can I fix this so both the textfields and the panel they are in have the size they should have?

This is some compilable code that shows the same problem:

package Test;
 
import java.awt.*;
import javax.swing.*;
 
public class TestWindow
{
	private JFrame frame;
	private JButton randombutton;
	private JButton savebutton;
	private JTextField seedinput;
	private JTextField amountinput;
 
	public TestWindow()
	{
		frame = new JFrame("Search Simulation");		
		frame.setPreferredSize(new Dimension(800,600));
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		int offset = 25;		
		JPanel loadbuttonpanel = new JPanel();
		loadbuttonpanel.setBackground(Color.BLUE);
		loadbuttonpanel.setLayout( new BoxLayout(loadbuttonpanel, BoxLayout.PAGE_AXIS) );
		randombutton = new JButton("test");
		loadbuttonpanel.add(randombutton);
		JPanel inputpanel = new JPanel();		
		inputpanel.setBackground(Color.GREEN);
		inputpanel.setLayout( new BoxLayout(inputpanel,BoxLayout.LINE_AXIS)); // if you comment out this line they get the right size, but the panel still takes up all the space for some reason
		seedinput = new JTextField(5);		
		amountinput = new JTextField(5);				
		inputpanel.add(seedinput);
		inputpanel.add(amountinput);
		loadbuttonpanel.add(inputpanel);
		frame.add(loadbuttonpanel);
		frame.pack();
		frame.setVisible(true);
	}
 
	public static void main(String[] args)
	{
		SwingUtilities.invokeLater( new Runnable()
		{
			public void run()
			{
				TestWindow test = new TestWindow();		
			}
		});
	}
}

Use the setpreferredSize method for the textfields and set the Dimensions the way you want them to be. You can even make a Dimension object and use that for the setpreferredSize for all your textfields since you want them the same size.

setPreferredSize doesn't do anything here, setMaximumSize does work. I'm still confused why the first example does work though, since I can't see any real difference between the two examples.