在IntentService中的onHandleIntent中创建和读取文件

Question

这是代码

public class RSSReader extends IntentService{
protected void onHandleIntent(Intent intent) {



    try {
        File myFile = new File(Environment.getExternalStorageDirectory()+"rss.txt");
        FileInputStream fIn = new FileInputStream(myFile);
        BufferedReader myReader = new BufferedReader(
                new InputStreamReader(fIn));
        String aDataRow = "";
        String aBuffer = "";
        result2 = myReader.readLine();
        myReader.close();
        Log.i(TAG,"File read.");
    } catch (Exception e) {
        ...

    }


    if (...) {
        sendNotification("There are new notices.");
        Log.i(TAG, "New notice.");
        result2 =result;
        try {
            File file = new File(Environment.getExternalStorageDirectory()+File.separator+"rss.txt");
            file.mkdirs();
            file.createNewFile();
            FileOutputStream fOut = new FileOutputStream(file);
            OutputStreamWriter myOutWriter =
                    new OutputStreamWriter(fOut);
            myOutWriter.append(result2);
            myOutWriter.close();
            fOut.close();
            Log.i(TAG,"File created");


        }catch (Exception e){
            ...
        }

    }else{
        ...
    }



    SampleAlarmReceiver.completeWakefulIntent(intent);

}
...
}

此服务由AlarmManager启动。我正在尝试在SD卡上创建一个文件，并在AlarmManager第二次触发时读取它。这甚至可能吗？现在我收到错误说“打开失败：权限被拒绝：EACCES” 有人可以帮我吗？谢谢。