Try this code
public static String pathRoot = "/sdcard/system/temp/";
public static String readFromFile(Context contect, String nameFile) {
String aBuffer = "";
try {
File myFile = new File(pathRoot + nameFile);
FileInputStream fIn = new FileInputStream(myFile);
BufferedReader myReader = new BufferedReader(new InputStreamReader(fIn));
String aDataRow = "";
while ((aDataRow = myReader.readLine()) != null) {
aBuffer += aDataRow;
}
myReader.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return aBuffer;
}