i am getting an IllegalStateException in this code

Question

I am trying to make a functionality for quick search of clients from database on some keystrokes from user, using an editable combobox. What i wanted to have is, user will put in some letters and if those lettters match with some clients, those clients will be remained in the current data model of the combobox.
The code is as follows. Please fix the exception occuring in the code. Thanks in Advance !!

Exception in thread "AWT-EventQueue-0" java.lang.IllegalStateException: Attempt to mutate in notification

import java.util.ArrayList;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.event.CaretEvent;
import javax.swing.event.CaretListener;

class ComboSearch extends JFrame implements CaretListener 
{
  private JComboBox mycombo;
  private ArrayList<String> list;
  private DefaultComboBoxModel<String> isolatemodel,model;

 public ComboSearch()
 {
   setSize(400, 400);
   setLayout(null);
   setDefaultCloseOperation(EXIT_ON_CLOSE);
   mycombo=new JComboBox();
   mycombo.setEditable(true);
   mycombo.setBounds(30,30, 350, 50);
   isolatemodel=new DefaultComboBoxModel();
   model=new DefaultComboBoxModel();
   list=new ArrayList();
   add(mycombo);
   mycombo.setModel(isolatemodel);
   ((JTextField)mycombo.getEditor()
      .getEditorComponent()).addCaretListener(this);
   setVisible(true);}

   private void addElements()
   {
    list.add("Rambhau, Vijay Nagar");
    list.add("Surya, Ashok Puri");
    list.add("Mourya, Shahjapur");
    list.add("Kishorji & sons, Bhopal");
    list.add("Fablica & jewels, Itanagar");
    list.add("Guru Kripa,Ujjain");
    list.add("Hariram Nai & Bakes, Indore");
    list.add("Ganesh Sev Bhandar, Harda");
    list.add("Greatsome Higs, Jabalpur");
    list.add("Treks and hains, Nalanda");
    list.add("Tata Indora, Hoshangabad");
    list.add("Paankhai Seth, Madurai");
    list.add("Katappa, Shikara");
    list.add("Gunjan Samosa, Vijay Nagar");
    list.add("Ramesh hustlers , Vijay Nagar");
  }
  public void makeModels()
  {
     addElements();
     list.stream().forEach((client) -> {
        isolatemodel.addElement(client);
     });
   }

  @Override
  public void caretUpdate(CaretEvent e)
  {
    String searchText=((JTextField)mycombo.getEditor()
                          .getEditorComponent()).getText();

    if(!searchText.isEmpty())
    {
        for(int i=0; i<isolatemodel.getSize();i++)
        {
            if(isolatemodel.getElementAt(i).contains(searchText))
            {
                model.removeAllElements();
                model.addElement(isolatemodel.getElementAt(i));
            }
        }
        mycombo.setModel(model);
        mycombo.showPopup();
    }
    else
    {
        mycombo.setModel(isolatemodel);
    }
  }
 }


public class Execute
{
  public static void main(String[] args)
  {
    ComboSearch searchIt=new ComboSearch();
    searchIt.makeModels();
  }
}

Answer 1

model.removeAllElements();
model.addElement(isolatemodel.getElementAt(i));

and if those lettters match with some clients, those clients will be remained in the current data model

Well, then it doesn't make sense to remove all the items every time you find a match. Then you will only ever have one entry left in the combo box.

You need to remove all the items BEFORE you start your loop processing and then just add back in the elements that match.

IllegalStateException:

You are trying to update the combo box model before processing of the typed event has finished processing.

Wrap the code in the listener in a SwingUtiltities.invokeLater(...) to the code will be executed after all processing has been finished.

Also, you would generally use a DocuementListener to be notified when the text of the editor has changed, not a CaretListener. The user could use the arrow keys to move the caret so there is no need to update the model in that case.