Altering displayed item name in JComboBox

Question

I filled a combo box with items from an entity class with the following code :

private void fillPositionComboBox(){
    EntityManager em = JPAUtilities.getEntityManagerFactory().createEntityManager();
    positionComboBox.removeAllItems();
    try{
        List<Position> list = em.createQuery("select p from Position p order by p.positionCode").getResultList();
        for(int i=0; i<list.size();i++){
            positionComboBox.addItem(list.get(i));
        }
    }
    catch(Throwable t){
        JOptionPane.showMessageDialog(this, t.toString());
    }
    finally{
        em.close();
    }
}

But when i ran the program and clicked the combo box, it displayed weird text on it's drop-down list. I want to replace those weird text with particular String say, like, string from the entity position.getPositionName();. Is it possible ? If so, pleaaase show the code on how to do it and give explanation of the code. Thank you so much for all of your help!

Answer 1

I don't know if I understood your question, but if you want that your JCombobox display a text different than what it stores, so you should create a class that have an internal text and a method toString() that return a different text like this :

class MyData{
  private String data;
  MyData(String text){
    data = text;
  }
  public String toString(){
    if(condition) return data;
    else return "Something else";
  }
}

Then you have to create a JCombobox that uses this class :

JComboBox<MyData> combo = new JComboxBox<>()

And put every result in a MyData object before adding it to the JCombobox.