如何在 Android 内部保存流式传感器数据？

Question

干杯。 我对 Android 编程比较陌生。 我一直在尝试实现一个应用程序，该应用程序读取传感器数据（加速度计 + 陀螺仪），然后通过单击按钮将其保存在内部。 我能够成功地从传感器获得读数。 但是，文件格式只保存一串数据，只显示当前数据，之前的数据被覆盖。 请参考这里的输出。 因此，我需要一些帮助来解决这个问题。

在 MainActivity.java 中，我注册了传感器侦听器：

@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
    // TODO Auto-generated method stub
}

// Obtain the sensor data from the phone
boolean IsDataRequested = false;
@Override
public void onSensorChanged(SensorEvent event) {
    Sensor sensor = event.sensor;
    if (sensor.getType() == Sensor.TYPE_ACCELEROMETER) {

        if (IsDataRequested == true){

            Log.d("Accelerometer", "Acc_X:" + event.values[0] + "Acc_Y:" + event.values[1] + "Acc_Z:" + event.values[2]);

            AccXText.setText("AccX:" + event.values[0]);
            AccYText.setText("AccY:" + event.values[1]);
            AccZText.setText("AccZ:" + event.values[2]);

            save(event);
        }
    }

    if (sensor.getType() == Sensor.TYPE_GYROSCOPE) {

        if (IsDataRequested == true) {

            Log.d("Gyroscope", "Gyro_X:" + event.values[0] + "Gyro_Y:" + event.values[1] + "Gyro_Z:" + event.values[2]);
            GyroXText.setText("GyroX:" + event.values[0]);
            GyroYText.setText("GyroY:" + event.values[1]);
            GyroZText.setText("GyroZ:" + event.values[2]);

            save(event);
        }
    }

}

然后在同一个文件中，我创建了 save 方法：

public void save(SensorEvent v) {
    float Acc_X = v.values[0];
    float Acc_Y = v.values[1];
    float Acc_Z = v.values[2];

    float Gyro_X = v.values[0];
    float Gyro_Y = v.values[1];
    float Gyro_Z = v.values[2];

    String accString = "Acc=" + "X:" + Acc_X + "Y:" + Acc_Y + "Z:" + Acc_Z;
    String gyroString = "Gyro=" + "X:" + Gyro_X + "Y:" + Gyro_Y + "Z:" + Gyro_Z;

    String FILENAME = "user";

    FileOutputStream fos = null;
    try {
        fos = openFileOutput(FILENAME, Context.MODE_PRIVATE);
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    }
    try {
        fos.write(accString.getBytes());
        fos.write(gyroString.getBytes());
        fos.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

单击按钮开始和停止发送数据：

private OnClickListener myOnSensorsRequestClickHandler = new OnClickListener() {
    @Override
            public void onClick(View sensors) {

            IsDataRequested = !IsDataRequested;
            Log.d("Sensors", "Sensors Button Pressed");

    }
};

我的目标是：

1. 要连续保存传感器数据流，直到单击同一按钮停止读取数据，然后将其保存在一个文件中。

2. 下次我开始和停止单击按钮时，它会添加另一个保存的文件，以便我可以在一个文件夹中保存多个文件。

非常感谢任何帮助或建议:)

Answer 1

我希望以下建议对您的以下要求有所帮助

    private OnClickListener myOnSensorsRequestClickHandler = new OnClickListener() {
    @Override
            public void onClick(View sensors) {

            IsDataRequested = !IsDataRequested;
            Log.d("Sensors", "Sensors Button Pressed");

            if(IsDataRequested)
            {
            //Create file name when start service button was clicked
        FILENAME = "user"+new Date().getTime() + ".txt"; //Here FILENAME is a path of file in global variable
        }

    }};



    boolean IsDataRequested = false;
    @Override
    public void onSensorChanged(SensorEvent event) {
        Sensor sensor = event.sensor;
        if (sensor.getType() == Sensor.TYPE_ACCELEROMETER) {

            if (IsDataRequested == true){



                Log.d("Accelerometer", "Acc_X:" + event.values[0] + "Acc_Y:" + event.values[1] + "Acc_Z:" + event.values[2]);

                AccXText.setText("AccX:" + event.values[0]);
                AccYText.setText("AccY:" + event.values[1]);
                AccZText.setText("AccZ:" + event.values[2]);

                save(FILENAME, event);
            }
            else
            {

            }
        }

        if (sensor.getType() == Sensor.TYPE_GYROSCOPE) {

            if (IsDataRequested == true) {

                Log.d("Gyroscope", "Gyro_X:" + event.values[0] + "Gyro_Y:" + event.values[1] + "Gyro_Z:" + event.values[2]);
                GyroXText.setText("GyroX:" + event.values[0]);
                GyroYText.setText("GyroY:" + event.values[1]);
                GyroZText.setText("GyroZ:" + event.values[2]);

                save(FILENAME, event);
            }
        }

    }
    public void save(String FILENAME, SensorEvent v) {
        float Acc_X = v.values[0];
        float Acc_Y = v.values[1];
        float Acc_Z = v.values[2];

        float Gyro_X = v.values[0];
        float Gyro_Y = v.values[1];
        float Gyro_Z = v.values[2];


//Here used StringBuffer instead of string for append string data

        StringBuffer accQyroData = "========";
        accQyroData.append("Acc=" + "X:" + Acc_X + "Y:" + Acc_Y + "Z:" + Acc_Z"+"\n"+"Gyro=" + "X:" + Gyro_X + "Y:" + Gyro_Y + "Z:" + Gyro_Z);
        accQyroData.append("========");

        //Use Stream for java append to file when you are dealing with raw data, binary
        appendUsingFileOutputStream(FILENAME, accQyroData);
    }

        /**
         * Use Stream for java append to file when you are dealing with raw data, binary
         * data
         * 
         * @param data
         */
        private static void appendUsingFileOutputStream(String fileName, String data) {
            OutputStream os = null;
            try {
                // below true flag tells OutputStream to append
                os = new FileOutputStream(new File(fileName), true);
                os.write(data.getBytes(), 0, data.length());
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                try {
                    os.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

• 要连续保存传感器数据流，直到单击同一按钮停止读取数据，然后将其保存在一个文件中。
• 下次我开始和停止单击按钮时，它会添加另一个保存的文件，以便我可以在一个文件夹中保存多个文件。