当这个错误发生时，我正在尝试将一个json转换回一个对象。我怎样才能摆脱这个错误？这是从json转换后我尝试获取其对象的类：

class Recognition implements Serializable {

    private final String id;
    private final String title;
    private final Float distance;
    private Object extra;
    private RectF location;
    private Integer color;
    private Bitmap crop;

    public Recognition(
            final String id, final String title, final Float distance, final RectF location) {
        this.id = id;
        this.title = title;
        this.distance = distance;
        this.location = location;
        this.color = null;
        this.extra = null;
        this.crop = null;
    }

    public void setExtra(Object extra) {
        this.extra = extra;
    }

    public Object getExtra() {
        return this.extra;
    }

    public void setColor(Integer color) {
        this.color = color;
    }

    public String getId() {
        return id;
    }

    public String getTitle() {
        return title;
    }

    public Float getDistance() {
        return distance;
    }

    public RectF getLocation() {
        return new RectF(location);
    }

    public void setLocation(RectF location) {
        this.location = location;
    }

    public Integer getColor() {
        return this.color;
    }

    public void setCrop(Bitmap crop) {
        this.crop = crop;
    }

    public Bitmap getCrop() {
        return this.crop;
    }

    @Override
    public String toString() {
        String resultString = "";
        if (id != null) {
            resultString += "[" + id + "] ";
        }

        if (title != null) {
            resultString += title + " ";
        }

        if (distance != null) {
            resultString += String.format("(%.1f%%) ", distance * 100.0f);
        }

        if (location != null) {
            resultString += location + " ";
        }

        if (color != null) {
            resultString += color + " ";
        }

        if (extra != null) {
            resultString += extra + " ";
        }

        if (crop != null) {
            resultString += encodeToBase64(crop, Bitmap.CompressFormat.JPEG, 100) + " ";
        }

        return resultString.trim();
    }

    public static String encodeToBase64(Bitmap image, Bitmap.CompressFormat compressFormat, int quality)
    {
        ByteArrayOutputStream byteArrayOS = new ByteArrayOutputStream();
        image.compress(compressFormat, quality, byteArrayOS);
        return Base64.encodeToString(byteArrayOS.toByteArray(), Base64.DEFAULT);
    }

    public static Bitmap decodeBase64(String input)
    {
        byte[] decodedBytes = Base64.decode(input, 0);
        return BitmapFactory.decodeByteArray(decodedBytes, 0, decodedBytes.length);
    }

    private void writeObject(java.io.ObjectOutputStream out) throws IOException {
        ByteArrayOutputStream stream = new ByteArrayOutputStream();
        crop.compress(Bitmap.CompressFormat.PNG, 100, stream);
        byte[] byteArray = stream.toByteArray();
        out.writeInt(byteArray.length);
        out.write(byteArray);
    }

    private void readObject(java.io.ObjectInputStream in) throws IOException, ClassNotFoundException {
        int bufferLength = in.readInt();
        byte[] byteArray = new byte[bufferLength];
        int pos = 0;
        do {
            int read = in.read(byteArray, pos, bufferLength - pos);
            if (read != -1) {
                pos += read;
            } else {
                break;
            }
        } while (pos < bufferLength);
        crop = BitmapFactory.decodeByteArray(byteArray, 0, bufferLength);
    }
}

我认为在构造器或位图转换中可能存在一些问题。但我不确定。所以如果你有什么解决办法的话。请告诉我。