Question

I have a JTextArea in a JPanel that I would like to use a JScrollPane with. I am using GridBagLayout. When I run it it seems the frame makes room for the JScrollPane but it does not show up, any help would be appreciated. I have been trying to study the docs.oracle page and here Add JScrollPane to a JPanel but for some reason it refuses to show up.

final JTextArea test= new JTextArea(5,30);
test.setLineWrap(true);
test.setWrapStyleWord(true);
test.setEditable(false);
JScrollPane spane = new JScrollPane(test);
spane.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);        

JFrame frame = new JFrame ();

frame.setSize(800, 250);
frame.setTitle("test1");
frame.setLocation(300, 300);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setResizable(false);
frame.getContentPane().add(spane);

GridBagConstraints k = new GridBagConstraints();
k.gridx = 4;
k.gridy = 5;
a.setConstraints(spane,k);
container.add(spane);

Answer 1

your variable container is JPanel? I think you forget to call the add() method. But below is my suggestion code.

import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.ScrollPaneConstants;
import javax.swing.SwingUtilities;

public class MyScrollPane extends JPanel
{

    public MyScrollPane()
    {   
        GridBagConstraints k = new GridBagConstraints();
        k.gridx = 4;
        k.gridy = 5;



        final JTextArea test= new JTextArea(5, 30);
        test.setLineWrap(true);
        test.setWrapStyleWord(true);
        test.setEditable(false);

        JScrollPane spane = new JScrollPane(test);
        spane.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);

        GridBagLayout gbl = new GridBagLayout();
        gbl.setConstraints(spane,k);

        JPanel panel = new JPanel(gbl);     
        panel.add(spane);
        add(panel);

    }


    private static void createAndShowGUI()
    {


        JFrame frame = new JFrame();
        frame.setSize(800, 250);
        frame.setTitle("test1");
        frame.setLocation(300, 300);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setResizable(false);
        frame.getContentPane().add(new MyScrollPane());



        frame.setVisible(true);
    }

    public static void main(String[] args)
    {
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run()
            {
                createAndShowGUI();             
            }
        });
    }

}