在文件资源管理器中找不到存储在设备内部存储中的文件

private void writeToFile(String s){
 try { // catches IOException below
        FileOutputStream fOut = openFileOutput(\"samplefile.txt\",
                                                MODE_WORLD_READABLE);
        OutputStreamWriter osw = new OutputStreamWriter(fOut); 
        osw.write(s);
        osw.flush();
        osw.close();
        FileInputStream fIn = openFileInput(\"samplefile.txt\");
        InputStreamReader isr = new InputStreamReader(fIn);
        char[] inputBuffer = new char[s.length()];
        isr.read(inputBuffer);
        String readString = new String(inputBuffer);
        Log.i(\"String\", readString);

    } catch (IOException ioe) {
        ioe.printStackTrace();
    }
}