Error in Implements on Java ME

Question

Hello,
I'm learning Java ME and when i complete the development of an application that uses RecordStore, it's simple a contact book, but when i completed the code i see that my program have an error and i use Eclipse, then it marks wrong codes in the left of the line with an X. Here is the error description:
The type simplecontacts must implement the inherited abstract method CommandListener.commandAction(Command, Displayable)Here is the code of my program:
package contacts;
import java.io.*;
import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;
import javax.microedition.rms.*;
import javax.microedition.lcdui.*;
public class simplecontacts extends MIDlet implements CommandListener, ItemStateListener {
     private Display display;
     private Alert alerta;
     private Form telainicial, adicionaReg;
     private TextField nome, telefone;
     private Command sair, adicionar, voltar, salvar, zerar;
     private RecordStore rs = null;
     String tipo, mensagem;
     boolean gravacaoOK = false;
     private ChoiceGroup tipo_contato;
     private String[] listaTipo = {"Amigos", "Família", "Trabalho"};
     public simplecontacts() {
          display = Display.getDisplay(this);
          sair = new Command("Sair", Command.EXIT, 0);
          adicionar = new Command("Adicionar Registros", Command.SCREEN, 1);
          zerar = new Command("Zerar Registros", Command.SCREEN, 1);
          voltar = new Command("Voltar", Command.SCREEN, 1);
          salvar = new Command("Salvar Registro", Command.SCREEN, 1);
          nome = new TextField("Nome:", "", 20, TextField.ANY);
          telefone = new TextField("Telefone:", "", 10, TextField.PHONENUMBER);
          telainicial = new Form("Simple Contacts");
          telainicial.addCommand(sair);
          telainicial.addCommand(adicionar);
          telainicial.addCommand(zerar);
          telainicial.setCommandListener(this);
          adicionaReg = new Form("Adiciona Contato");
          tipo_contato = new ChoiceGroup("Tipo do Contato", Choice.POPUP, listaTipo, null);
          adicionaReg.append(nome);
          adicionaReg.append(telefone);
          adicionaReg.append(tipo_contato);
          adicionaReg.addCommand(salvar);
          adicionaReg.addCommand(voltar);
          adicionaReg.setItemStateListener(this);
          adicionaReg.setCommandListener(this);
     protected void destroyApp(boolean arg0) {
          notifyDestroyed();
     protected void pauseApp() {
          // TODO Auto-generated method stub
     protected void startApp() throws MIDletStateChangeException {
          try {
               rs = RecordStore.openRecordStore("SimpleContacts", true);
          } catch (Exception exc) {
               mostrarAlerta("Erro ao abrir o RecordStore -", exc.toString());
          display.setCurrent(telainicial);
     private void mostrarAlerta(String tipoAlerta, String msg) {
          alerta = new Alert(tipoAlerta, msg, null, AlertType.WARNING);
          alerta.setTimeout(Alert.FOREVER);
          display.setCurrent(alerta);
     private void adicionarRegistro() {
          try {
               ByteArrayOutputStream BAOS = new ByteArrayOutputStream();
               DataOutputStream DOS = new DataOutputStream(BAOS);
               DOS.writeUTF(nome.getString());
               DOS.writeUTF(telefone.getString());
               DOS.writeInt(tipo_contato.getSelectedIndex());
               byte [] bRec = BAOS.toByteArray();
               rs.addRecord(bRec, 0, bRec.length);
               DOS.close();
               BAOS.close();
               display.setCurrent(telainicial);
          } catch (Exception exc) {
               mostrarAlerta("Erro ao adicionar -", exc.toString());
     private void zerarRegistros(){
          try {
               rs.closeRecordStore();
               RecordStore.deleteRecordStore("SimpleContacts");
               rs = RecordStore.openRecordStore("SimpleContacts", true);
          } catch (Exception exc) {
               mostrarAlerta("Erro ao recriar o RecordStore -", exc.toString());
          display.setCurrent(telainicial);
     public void itemStateChanged (Item item) {
          if (item instanceof TextField) {
               String teste = ((TextField)item).getString();
               if (teste != "") {
                    gravacaoOK = true;
     public void CommandAction(Command command, Displayable displayable) {
          if (command == sair) {
               try {
                    rs.closeRecordStore();
               } catch (Exception exc) {
                    mostrarAlerta("Erro fechando o RedcorStore -", exc.toString());
               destroyApp(true);
          } else if (command == adicionar) {
               nome.setString("");
               telefone.setString("");
               display.setCurrent(adicionaReg);
          } else if (command == salvar) {
               if (gravacaoOK == false) {
                    mostrarAlerta("Registro vazio não será salvo", "Tente Novamente");
               } else {
                    adicionarRegistro();
          } else if (command == zerar) {
               zerarRegistros();
          } else if (command == voltar) {
               display.setCurrent(telainicial);
What i have to do?
Thanks,
Nathan Paulino Campos

Answer 1

Java is case sensitive. commandAction, not CommandAction.
db