JComboBox with search in database?

Hello

JCombobox is setEditable(true) for searching in my database. when I
add words to search I need return all results for the word and popup
for Jcombobox open with all results found.

I am trying this.
[code]
//JComboBox implements ComboBoxModel
public class JComboModelFuncoes extends AbstractListModel implements
ComboBoxModel{
    private Object selectedItem;
    private List<Funcoes> listaFuncoes = null;

    public JComboModelFuncoes(List<Funcoes> lista){
        listaFuncoes = lista;
    }

    @Override
    public int getSize() {
        return listaFuncoes.size();
    }

    @Override
    public Object getElementAt(int index) {
        return listaFuncoes.get(index);
    }

    @Override
    public void setSelectedItem(Object anItem) {
        selectedItem = anItem;
    }

    @Override
    public Object getSelectedItem() {
        return selectedItem;
    }
}

//here how to trying in my JFrame
public void editorCombo(){
    comboPesquisa.setMaximumRowCount(10);
    JTextComponent t = null;
    t =
(JTextComponent)comboPesquisa.getEditor().getEditorComponent();
    t.addKeyListener(new KeyListener() {
            @Override
            public void keyTyped(KeyEvent e) {
                e.getKeyChar();
            }

            @Override
            public void keyPressed(KeyEvent e) {
                if(e.getKeyCode() == KeyEvent.VK_ENTER){

                }
            }

            @Override
            public void keyReleased(KeyEvent e) {
                //throw new UnsupportedOperationException("Not
supported yet.");
                List<Funcoes> lista = new
FuncoesDAO().retornaFuncao(String.valueOf(e.getKeyChar()).toUpperCase());
                JComboModelFuncoes mf = new
JComboModelFuncoes(lista);
                comboPesquisa.setModel(mf);
                comboPesquisa.setPopupVisible(true);
            }
        });

}

//here my DAO
public List<Funcoes> retornaFuncao(String funcao){
         List<Funcoes> lista = new ArrayList<Funcoes>();
         PreparedStatement stm = null;
         ResultSet rs = null;
         try{
             stm = this.con.prepareStatement("SELECT * FROM funcoes
WHERE funcao LIKE ?");
             stm.setString(1, "%" + funcao + "%");
             rs = stm.executeQuery();
             while(rs.next()){
                 Funcoes f = new Funcoes();
                 f.setIdFuncao(rs.getLong("id_funcao"));
                 f.setFuncao(rs.getString("funcao"));
                 lista.add(f);
             }
         }catch (SQLException e){
             JOptionPane.showMessageDialog(null, "Erro tentando
consultar fun=E7=E3o", "Erro", JOptionPane.ERROR_MESSAGE);
         }finally{
            try {
                rs.close();
                stm.close();
            } catch (SQLException ex) {
 
Logger.getLogger(FuncoesDAO.class.getName()).log(Level.SEVERE, null,
ex);
            }

         }
         return lista;
     }

[/code]

How to make a search with JComboBox with enter one by one word ?

thanks