java.io.IOException : Stream Closed ObjectOutputStream

Question

我不断收到 java.io.IOException: Stream Closed，我似乎无法理解为什么。我在按钮按下(如下所示的对象)上创建两个 SensorReadings 对象(每个对象发送一个用于文件名的唯一字符串)，该按钮打开两个 ObjectoutputStream 并写入两个单独的文件。我第一次使用它时，它工作得完美无缺，没有任何异常(exception)。当我完成对文件的写入后，我按下另一个按钮来关闭 Objectoutputstreams 并删除我写入的文件。

当我再次尝试按下按钮，使用新的 Objectoutputstreams 和具有不同名称的新文件创建新的 SensorReadings 对象时，每次尝试写入文件时，我都会遇到 java.io.IOException: Stream Closed。

关闭应用程序并重新启动将导致第一次再次完美工作，但第二次++时我遇到了同样的错误。

代码:

public class SensorReadings {
    private String macAddress;
    private String cacheFileAccelerationName;
    private String cacheFileEulerAnglesName;
    private File cacheFileAcceleration;
    private File cacheFileEulerAngles;
    private ObjectOutputStream accelerationStreamWriter;
    private ObjectOutputStream euleranglesStreamWriter;

    public SensorReadings(String macAddress, Context context) {
        SimpleDateFormat dateFormata = new SimpleDateFormat("yyyy.MM.dd'-'HH:mm:ss");
        this.macAddress = macAddress;
        cacheFileAccelerationName = dateFormata.format(Calendar.getInstance().getTime())+macAddress+"-acceleration-cache";
        cacheFileEulerAnglesName = dateFormata.format(Calendar.getInstance().getTime())+macAddress+"-eulerangles-cache";

        cacheFileAcceleration = new File(context.getCacheDir(), cacheFileAccelerationName);
        cacheFileEulerAngles = new File(context.getCacheDir(), cacheFileEulerAnglesName);

        try {
            accelerationStreamWriter = new ObjectOutputStream(new FileOutputStream(cacheFileAcceleration));
            euleranglesStreamWriter = new ObjectOutputStream(new FileOutputStream(cacheFileEulerAngles));
        } catch (FileNotFoundException e){
            e.printStackTrace();
        } catch (IOException e){
            e.printStackTrace();
        }
    }

    public void addAccelerationData(AccelerationReading reading){
        try {
            accelerationStreamWriter.writeUnshared(reading);
            accelerationStreamWriter.reset();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public void addEulerAngleData(EulerAnglesReading reading){
        try {
            euleranglesStreamWriter.writeUnshared(reading);
            euleranglesStreamWriter.reset();
        } catch (IOException e) {
            e.printStackTrace();
        }

    public void closeFiles(){
        try {
            euleranglesStreamWriter.flush();
            accelerationStreamWriter.flush();
            euleranglesStreamWriter.close();
            accelerationStreamWriter.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        cacheFileEulerAngles.delete();
        cacheFileAcceleration.delete();
    }
}

每次我在创建新对象后尝试写入时都会遇到错误:

03-27 21:00:38.526 9882-9894/com.appitude.appitude W/System.err: java.io.IOException: Stream Closed
03-27 21:00:38.526 9882-9894/com.appitude.appitude W/System.err:     at java.io.FileOutputStream.write(FileOutputStream.java:310)
03-27 21:00:38.526 9882-9894/com.appitude.appitude W/System.err:     at java.io.ObjectOutputStream$BlockDataOutputStream.drain(ObjectOutputStream.java:1946)
03-27 21:00:38.526 9882-9894/com.appitude.appitude W/System.err:     at java.io.ObjectOutputStream$BlockDataOutputStream.writeByte(ObjectOutputStream.java:1986)
03-27 21:00:38.526 9882-9894/com.appitude.appitude W/System.err:     at java.io.ObjectOutputStream.writeFatalException(ObjectOutputStream.java:1612)
03-27 21:00:38.526 9882-9894/com.appitude.appitude W/System.err:     at java.io.ObjectOutputStream.writeUnshared(ObjectOutputStream.java:432)
03-27 21:00:38.526 9882-9894/com.appitude.appitude W/System.err:     at com.appitude.appitude.SensorReadings.addAccelerationData(SensorReadings.java:103)
03-27 21:00:38.526 9882-9894/com.appitude.appitude W/System.err:     at com.appitude.appitude.BLE_Connections.lambda$null$31d3e978$1$BLE_Connections(BLE_Connections.java:265)
03-27 21:00:38.526 9882-9894/com.appitude.appitude W/System.err:     at com.appitude.appitude.BLE_Connections$$Lambda$24.apply(Unknown Source)
03-27 21:00:38.526 9882-9894/com.appitude.appitude W/System.err:     at com.mbientlab.metawear.impl.DeviceDataConsumer.call(DeviceDataConsumer.java:51)
03-27 21:00:38.527 9882-9894/com.appitude.appitude W/System.err:     at com.mbientlab.metawear.impl.StreamedDataConsumer.lambda$addDataHandler$1$StreamedDataConsumer(StreamedDataConsumer.java:138)
03-27 21:00:38.527 9882-9894/com.appitude.appitude W/System.err:     at com.mbientlab.metawear.impl.StreamedDataConsumer$$Lambda$1.onResponseReceived(Unknown Source)
03-27 21:00:38.527 9882-9894/com.appitude.appitude W/System.err:     at com.mbientlab.metawear.impl.JseMetaWearBoard.lambda$null$13$JseMetaWearBoard(JseMetaWearBoard.java:699)
03-27 21:00:38.527 9882-9894/com.appitude.appitude W/System.err:     at com.mbientlab.metawear.impl.JseMetaWearBoard$$Lambda$30.onChange(Unknown Source)
03-27 21:00:38.527 9882-9894/com.appitude.appitude W/System.err:     at com.mbientlab.metawear.android.BtleService$1.onCharacteristicChanged(BtleService.java:188)
03-27 21:00:38.527 9882-9894/com.appitude.appitude W/System.err:     at android.bluetooth.BluetoothGatt$1.onNotify(BluetoothGatt.java:402)
03-27 21:00:38.527 9882-9894/com.appitude.appitude W/System.err:     at android.bluetooth.IBluetoothGattCallback$Stub.onTransact(IBluetoothGattCallback.java:177)
03-27 21:00:38.527 9882-9894/com.appitude.appitude W/System.err:     at android.os.Binder.execTransact(Binder.java:573)

Answer 1

问题已解决。正在传输数据然后写入文件的连接的蓝牙设备在流关闭时不会停止，并在激活新 session 时继续尝试使用相同的流。