Show Regitry's in The Main Form on Java ME

[Nathan Campos]

Hello,
I'm learning Java ME and i was building an application that is a simple contact book, but in the main form it only have menus, because i don't know how i can list the registry's on it, remember that i want to list only the names in the list and how i can add more registry's, not overwrite the existing one. Here is my code:

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 com, Displayable dis) {
		if (com == sair) {
			try {
				rs.closeRecordStore();
			} catch (Exception exc) {
				mostrarAlerta("Erro fechando o RedcorStore -", exc.toString());
			}
			destroyApp(true);
		} else if (com == adicionar) {
			nome.setString("");
			telefone.setString("");
			display.setCurrent(adicionaReg);
		} else if (com == salvar) {
			if (gravacaoOK == false) {
				mostrarAlerta("Registro vazio não será salvo", "Tente Novamente");
			} else {
				adicionarRegistro();
			}
		} else if (com == zerar) {
			zerarRegistros();
		} else if (com == voltar) {
			display.setCurrent(telainicial);
		}
	}
}

Thanks,
Nathan Paulino Campos

[peter_budo]

Maybe you can get something useful from here