jList1.setBorder(new javax.swing.border.LineBorder(new java.awt.Color(0, 0, 0)));
jList1.setMinimumSize(new java.awt.Dimension(20, 20));
jList1.setValueIsAdjusting(true);
getContentPane().add(jList1);
jList1.setBounds(0, 0, 0, 0);

import javax.swing.*;

public class JListProba extends JPanel {

    JList list;

    public JListProba() {
        String[] listPodaci = {"jedan", "dva", "tri"};
        list = new JList(listPodaci);

        list.setBorder(new javax.swing.border.LineBorder(new java.awt.Color(0, 0, 0)));
        list.setMinimumSize(new java.awt.Dimension(20, 20));
        list.setValueIsAdjusting(true);
        list.setBounds(0, 0, 0, 0);

        JScrollPane listPane = new JScrollPane(list);

        add(listPane);
    }

    /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     */
    private static void createAndShowGUI() {
        //Make sure we have nice window decorations.
        JFrame.setDefaultLookAndFeelDecorated(true);

        //Create and set up the window.
        JFrame frame = new JFrame("JListProba");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //Create and set up the content pane.
        JListProba proba = new JListProba();
        proba.setOpaque(true);
        frame.setContentPane(proba);

        //Display the window.
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }


}