java - 服务中存储类的同步和/或互斥

Question

我需要在我的应用程序中同时读取和写入具有不同 jobIntentServices 的公共(public)文件。一个服务(生产者)将数据写入文件中，而另一个服务(消费者)检查共享文件中是否有数据。如果有数据，则发送该数据；如果数据传输成功，则删除该文件。我创建了以下存储 Controller 类:

public class Storage {
private static final String TAG = "Storage";

public void writeToFile(String filePath, String data, Context context) {
    try {
        OutputStreamWriter outputStreamWriter = new OutputStreamWriter(context.openFileOutput(filePath, Context.MODE_PRIVATE));
        outputStreamWriter.write(data);
        outputStreamWriter.close();
    }
    catch (IOException e) {
        Log.e(TAG, "File write failed: " + e.toString());
    }
}

public String readFromFile(String filePath, Context context) {

    String ret = "";

    try {
        InputStream inputStream = context.openFileInput(filePath);

        if ( inputStream != null ) {
            InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
            String receiveString = "";
            StringBuilder stringBuilder = new StringBuilder();

            while ( (receiveString = bufferedReader.readLine()) != null ) {
                stringBuilder.append("\n").append(receiveString);
            }

            inputStream.close();
            ret = stringBuilder.toString();
        }
    }
    catch (FileNotFoundException e) {
        Log.e(TAG, "File not found: " + e.toString());
    } catch (IOException e) {
        Log.e(TAG, "Can not read file: " + e.toString());
    }

    return ret;
}

public boolean fileExists(String filename, Context context) {
    File file = context.getFileStreamPath(filename);
    if(file == null || !file.exists()) {
        return false;
    }
    return true;
}

public boolean deleteFile(String filename, Context context){
    File file = context.getFileStreamPath(filename);
    return file.delete();
}

该类不是单例。

Answer 1

我用单例类并使用锁解决了这个问题:

Lock lockDeviceData = new ReentrantLock();