Netbeans lookup not getting executed first time when the application is started - netbeans

Question

I have an application in which lookup provider is in explorer window and it is a jcomboBox. Its selected value is provided as lookup to other top components and displayed one in editor and one in output window area. The value of the jcombobox is saved at the time of closing the application and initialized into the jcombobox when the application is started.
When I clean and build the application and start the application, the initial value displayed in the jcombobox is not updated in the lookup and listner windows display uninitialized values. Once the new value is selected in the jcombobox it gets displayed in the other windows.
If I close the application without changing the value of the jcombobox and start the application, the lookup is not updated.
If I change the selection in the combobox, close the application and start again, the lookup gets updated.
I expect anytime when the application is started, the other windows will get the value of the lookup. Any help in this regards will be appreciated. Thanks in advance.
The code for the explorer window which provides the lookup is as follows:
public final class ProviderTopComponent extends TopComponent {
public ProviderTopComponent() {
initComponents();
setName(Bundle.CTL_ProviderTopComponent());
setToolTipText(Bundle.HINT_ProviderTopComponent());
associateLookup(new AbstractLookup(content));
}
private void initComponents() {
jComboBox1 = new javax.swing.JComboBox();
jComboBox1.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "Item 1", "Item 2", "Item 3", "Item 4" }));
jComboBox1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jComboBox1ActionPerformed(evt);
}
});
private void jComboBox1ActionPerformed(java.awt.event.ActionEvent evt) {
str = (String) jComboBox1.getSelectedItem();
content.set(Collections.singleton(str), null);
}
private final InstanceContent content = new InstanceContent();
String str;
// Variables declaration - do not modify
private javax.swing.JComboBox jComboBox1;
void writeProperties(java.util.Properties p) {
// better to version settings since initial version as advocated at
// http://wiki.apidesign.org/wiki/PropertyFiles
p.setProperty("version", "1.0");
p.setProperty("val", (String) jComboBox1.getSelectedItem());
}
void readProperties(java.util.Properties p) {
String version = p.getProperty("version");
// TODO read your settings according to their version
String v = p.getProperty("val");
if(v != null) {
jComboBox1.setSelectedItem(v);
}
}
}
The code for the lookup listener window is as follows:
public final class Listner_1TopComponent extends TopComponent implements LookupListener{
public Listner_1TopComponent() {
initComponents();
setName(Bundle.CTL_editorTopComponent());
setToolTipText(Bundle.HINT_editorTopComponent());
}
...
private void initComponents() {
...
jLabel1 = new javax.swing.JLabel();
...
Collection<? extends String> str_collection;
private Lookup.Result<String> result = null;
String str;
// Variables declaration - do not modify
private javax.swing.JLabel jLabel1;
// End of variables declaration
#Override
public void componentOpened() {
result = org.openide.util.Utilities.actionsGlobalContext().lookupResult(String.class);
result.addLookupListener(this);
}
#Override
public void componentClosed() {
result.removeLookupListener(this);
}
#Override
public void resultChanged(LookupEvent le) {
str_collection = result.allInstances();
if (str_collection.isEmpty()) {
} else {
str = str_collection.iterator().next();
}
jLabel1.setText(str);
jLabel1.repaint();
}
}