BufferedReader br = null;
FileReader fr = null;
File folderx = new File(Environment.getExternalStorageDirectory() +
          File.separator + "Zam_Gen");
boolean success = true;
if (!folderx.exists()) {
   success = folderx.mkdirs();// Create Zam_Gen folder , if does not exist
}
if (success) {
   // Do something on success
   File myFile = new File(folderx, "data.txt");//.PES
   if (!myFile.exists()){
       myFile.createNewFile();// Create data.txt file , if does not exist
       Toast.makeText(this,"No data file, Created a data file.",Toast.LENGTH_SHORT).show();
   }else{
       fr = new FileReader(myFile);
       br = new BufferedReader(fr);

       String sCurrentLine;

       boolean boolNull =  true;

       while ((sCurrentLine = br.readLine()) != null) {
           list.add(sCurrentLine);//read by line and use it, this add it to ArrayList
           boolNull =  false;
       }

       br.close();
       fr.close();
       if (boolNull) {
           Toast.makeText(this, "Load OK!,BUT NO DATA", Toast.LENGTH_SHORT).show();
       }else{
           Toast.makeText(this, "Load data OK!", Toast.LENGTH_SHORT).show();
       }
   }
}
}catch (Exception e){}

BufferedWriter bw = null;
FileWriter fw = null;
try {
  File folder = new File(Environment.getExternalStorageDirectory() +
                   File.separator + "Zam_Gen");
  boolean success = true;
  if (!folder.exists()) {
     success = folder.mkdirs();
  }
  if (success) {
     // Do something on success
     File myFile = new File(folder, "data.txt");//.PES

     fw = new FileWriter(myFile, false); // true ... ie. write add , false ... ie override
     bw = new BufferedWriter(fw);

     String string = "";

     bw.write(string);

     bw.close();
     fw.close();
  }
}catch (Exception e){

}