如何在jframe java swing中调整jscrollpane的大小？

Question

i am new to java swing, currently i am developing an application using java swing, i am facing the problem is that when i populate my JList with JScrollPane it is displaying on my whole jframe. code:

List<Element> parentElements = xmlUtil.getParentElements();
        String title = "License";
        JFrame f = new JFrame(title);



        String[] parentTags = new String[parentElements.size()];
        for(int i=0;i<parentElements.size();i++)
        {
            System.out.println(parentElements.get(i).getName());
            parentTags[i] = parentElements.get(i).getName();
        }

        JList list = new JList(parentTags);
        JScrollPane scrollPane = new JScrollPane(list, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
        scrollPane.setPreferredSize(new Dimension(50,40)); 
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        Container contentPane = f.getContentPane();

        contentPane.add(scrollPane);

        f.setSize(900, 700);
        f.setVisible(true);

Output:

i want output like this so it can cover small area in jframe

Please tell me how to resize it ? as i am stuck into this problem from very long time.

Answer 1

Add the JScrollPane to a JPanel and then add the JPanel to the JFrame :

    JScrollPane scrollPane = new JScrollPane(list, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Container contentPane = f.getContentPane();

    JPanel panel = new JPanel();
    panel.add(scrollPane);
    panel.setPreferredSize(new Dimension(50,40));
    contentPane.add(panel);

Then you can use the setPreferredSize method of the JPanel to resize it how you want.

Also consider using a good layout manager. I use a combination of two (primarily):

1. Netbeans' drag-and-drop WYSIWYG editor (Matisse)
2. MigLayout -- easily the best hand-written layout available. Some learning curve required (but less learning than the rest).