Problema ao gravar no sistemas de arquivos do celular

import javax.microedition.io.Connector;
import javax.microedition.io.file.*;

public cExportador(){
        try {
            String uri = System.getProperty("fileconn.dir.photos") + "export.txt";
            fc = (FileConnection) Connector.open(uri, Connector.READ_WRITE);
            anterior = new StringBuffer(""); //le o conteudo anterior do arquivo para nao perde-lo
            if (! fc.exists())
                fc.create();
            else{
                in = new InputStreamReader(fc.openInputStream());

                int intCarac = in.read();
                while (intCarac != -1){ //Atribui o arquivo anterior ao StringBuffer anterior;
                    char c = (char) intCarac;
                    anterior.append(c);
                    intCarac = in.read();
                }
                in.close();
            }
                        
            out = fc.openOutputStream();
            saida = new PrintStream(out);
            
            saida.println(anterior.toString()); //gera um stream de saída
        } catch (IOException ex) {
            ex.printStackTrace();
        } catch(SecurityException e){
            e.printStackTrace();
        }
    }