import java.awt.BorderLayout;
import javax.swing.AbstractListModel;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;

public class MyPanel extends JPanel {
    public MyPanel() {
        // Create lists.
        JList list1 = new JList(new MyListModel("Left item "));
        JList list2 = new JList(new MyListModel("Right item "));
        list1.setLayoutOrientation(JList.VERTICAL);
        list2.setLayoutOrientation(JList.VERTICAL);
        JScrollPane scrollPane1 = new JScrollPane(list1);
        JScrollPane scrollPane2 = new JScrollPane(list2);

        // Create a split pane.
        JSplitPane splitPane = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,
                scrollPane1, scrollPane2);

        // Set the split pane as a root pane.
        setLayout(new BorderLayout());
        add(splitPane, BorderLayout.CENTER);
    }

    // Data model for JList.
    public class MyListModel extends AbstractListModel {
        private String prefix;

        public MyListModel(String prefix) {
            this.prefix = prefix;
        }

        @Override
        public Object getElementAt(int index) {
            return prefix + index;
        }

        @Override
        public int getSize() {
            return 100;
        }
    }
}