Unknown error in source

Question

I have just installed JDeveloper 9i version 9.0.3.1 (build 1107).
I've created a simple panel which holds a JSplitPane. the splitpane contains a list. The code compiles and runs successfully. I receive the above error when i try to move to the UI Editor.
The Code:
import javax.swing.JPanel;
import java.awt.Dimension;
import java.awt.Color;
import java.awt.Rectangle;
import javax.swing.JScrollPane;
import javax.swing.JList;
public class DailyPanel extends JPanel {
private JScrollPane jScrollPane1 = new JScrollPane();
private JList jList1;
public DailyPanel() {
try {
jbInit();
} catch(Exception e) {
e.printStackTrace();
private void jbInit() throws Exception {
this.setSize(new Dimension(379, 124));
this.setBackground(Color.white);
this.setLayout(null);
jList1 = new JList(Constants.DAYS_OF_WEEK);
jScrollPane1.setBounds(new Rectangle(100, 45, 120, 40));
jScrollPane1.getViewport().add(jList1, null);
this.add(jScrollPane1, null);
The error message dialog indicates the problem is :
java.lang.NullPointerException
     int javax.swing.JList$2.getSize()
          JList.java:297
This causes JDeveloper to behave strange (some of the windows are disabled)

Answer 1

I would recommend to move the instantiation of the JList out of jbInit and to the attribute declaration section. This might help.