如何使用HttpURLConnection在多部分请求中发送JPEG图像

Question

我想将图像从画廊/相机发送到服务器。该图像被压缩Bitmap，并被转换为ByteArray。问题是服务器返回错误-> file is not JPEG。这意味着服务器无法将我的内容识别为JPEG。有什么事吗

这是我对多部分请求的API调用。

val data: ByteArray = convertBitmapToByteArray(bmp)
val con = url.openConnection() as HttpURLConnection
            con.apply {
                requestMethod = method
                useCaches = false
                doOutput = true
                doInput = true
                addRequestProperty("Connection", "Keep-Alive")
                addRequestProperty("Cache-Control", "no-cache")
                addRequestProperty("Content-Type", "multipart/form-data")
                addRequestProperty("X-API-Key", apiType.apiKey)
                addRequestProperty("X-Session", session)
            }

            val request = DataOutputStream(con.outputStream)

            request.apply {
                writeBytes("$TWO_HYPHENS$BOUNDARY$CRLF")
                writeBytes("Content-Disposition: form-data; name=\"" +
                        ATTACHMENT_NAME + "\";filename=\"" +
                        filename + "\"" + CRLF)
                writeBytes(CRLF)
                write(data)
                writeBytes(CRLF)
                writeBytes("$TWO_HYPHENS$BOUNDARY$TWO_HYPHENS$CRLF")
                flush()
                close()
            }

            val code = con.responseCode
            if (code/100 != 2) {
                if (code == 502){
                    //handle special error
                } else if (code >= 400) {
                    //handle errors
                }
                //handle errors
            }
            return getHttpResponseAsJson(con)

转换位图：

fun convertBitmapToByteArray(bmp: Bitmap): ByteArray{
    val stream = ByteArrayOutputStream()
    bmp.compress(Bitmap.CompressFormat.JPEG, 100, stream)
    return stream.toByteArray()
}