我一直在编写一个应用程序，它应该通过蓝牙将文件发送到运行相同应用程序的另一台设备。我有成功发送文件但有一个大问题...当我发送一个太大的文件时，我得到了一个内存不足的例外。
因此，为了找到解决方法，我开始加载并发送文件块。它似乎按照我想要的方式运行，直到我继续打开收到的文件。首批收到的照片之一看起来像corrupted image。但大多数其他照片，或APK文件（无论misc。＆＃34;大＆＃34;文件）根本不打开。我相信问题出现在我的循环逻辑中，即发送数据块。可能我错过了一些简单的东西，只是反复发送相同的数据块？
请查看下面的代码，如果您能发现我正在制作的错误，请告诉我。这是开始发送的线程：
thread {
val file = fileManager.select(fileName)
val inStream = file.inputStream(
val length = file.length()
val b = ByteArray(1000000)
var count = 0 //used to keep track of progress through file
var off = 0
var numRead = 0
val notificationManager = activity.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
val notificationBuilder = NotificationCompat.Builder(activity)
notificationBuilder.setContentTitle("File Transfer")
.setSmallIcon(R.drawable.abc_btn_radio_material)
.setContentText("Sending $fileName...")
.setOngoing(true)
.setProgress(length.toInt(), 0, false)
notificationManager.notify(BTS_Constants.NOTIFICATION_ID, notificationBuilder.build())
val header = "${BTS_Constants.START_MARKER}$fileName:$length:".toByteArray()
BluetoothService.send(header, header.size.toLong(), header.size)
while (count < length){
try {
numRead = inStream.read(b, off, 1000000)
off+=numRead // is problem here?
count+=numRead
if (!(numRead>=0))break
off = 0
}catch (ae:ArrayIndexOutOfBoundsException) {
BluetoothService.log("end of file reached", ae)
}
if (BluetoothService.send(b, length, count)){
Log.d(TAG, "count: $count\nlength: ${length.toInt()}")
notificationBuilder.setProgress(length.toInt(), count, false)
notificationManager.notify(BTS_Constants.NOTIFICATION_ID, notificationBuilder.build())
}
}
notificationBuilder.setProgress(0, 0, false)
.setOngoing(false)
.setContentText("Finished sending")
notificationManager.notify(BTS_Constants.NOTIFICATION_ID, notificationBuilder.build())
}
在文件的一个块中读取内存，给定一个头并使用BluetoothService.send()函数发送。如果send()返回true，则更新进度。这是BluetoothService.send()：
@Synchronized fun send(bytes:ByteArray, fileLength:Long, progress:Int):Boolean{
var synThread:ConnectedThread? = null
synchronized(this@BluetoothService){
synThread = mConnectedThread
}
var success:Boolean
try {
synThread?.write(bytes, progress, fileLength.toInt())
success = true
}catch (e:Exception){
success = false
}
return success
}
send函数调用synThread的write()函数。 synThread是ConnectedThread？宾语。以下是包含写函数定义的ConnectedThread的定义：
class ConnectedThread(val socket: BluetoothSocket) : Thread(){
var fileName:String = ""
var fileLength:Int = 0
val inStream:InputStream
val outStream:OutputStream
val outBuffer:ByteArray
var inBuffer:ByteArray
var fOut:FileOutputStream? = null
var bytes:Int = 0
var active = true
val notifyManager = BluetoothService.context?.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
var notifyBuilder:NotificationCompat.Builder? = null
init {
inStream = socket.inputStream
outStream = socket.outputStream
outBuffer = ByteArray(1000000)
inBuffer = ByteArray(1024)
notifyBuilder = NotificationCompat.Builder(BluetoothService.context)
notifyBuilder?.setSmallIcon(R.drawable.abc_btn_radio_material)
?.setContentTitle("Downloading")
}
override fun run() {
BluetoothService.log("$this waiting to read . . .")
while (active){
try {
bytes += inStream.read(inBuffer)
var header = String(inBuffer)
if (header.startsWith(BTS_Constants.START_MARKER)){
this.fileName = header.substringAfter(BTS_Constants.START_MARKER).substringBefore(":")
this.fileLength = (header.substringAfter(":").substringBeforeLast(":")).toInt()
val path = "${Environment.DIRECTORY_DOWNLOADS}/$fileName"
val outFile = File(Environment.getExternalStoragePublicDirectory(path).toURI())
if (outFile.exists()){
BluetoothService.log("file already exists")
}else{
outFile.createNewFile()
}
fOut = outFile.outputStream()
inBuffer = ByteArray(1000000)
bytes = 0
notifyBuilder!!.setContentText("file: $fileName")
.setProgress(0, 0, true)
.setOngoing(true)
.setVibrate(LongArray(1){
10000L
})
notifyManager.notify(BTS_Constants.NOTIFICATION_ID, notifyBuilder!!.build())
BluetoothService.log("name = $fileName, length = $fileLength")
}else if(bytes>=fileLength){
notifyBuilder!!.setProgress(0, 0, false)
.setContentText("Download complete")
.setOngoing(false)
notifyManager.notify(BTS_Constants.NOTIFICATION_ID, notifyBuilder!!.build())
//possibly save last bytes of file here
}else{
BluetoothService.log("bytes: $bytes read: $inBuffer")
fOut?.write(inBuffer)
}
BluetoothService.log("read $bytes bytes: $inBuffer")
}catch (ioe:IOException){
BluetoothService.log("failed to read from $socket", ioe)
cancel()
}
}
}
//WRITE FUNCTION
fun write(bytes:ByteArray, progress: Int, length:Int){
BluetoothService.log("writing bytes from $this")
outStream.write(bytes)
outStream.flush()
BluetoothService.log("bytes written")
}
fun cancel(){
BluetoothService.log("closing socket, read may fail - this is expected")
active = false
socket.close()
}
}
所以我再次相信这是在我的循环逻辑中的某个地方犯了一个错误，但我看不到它。请帮我找到这个问题和解决方案。谢谢。
更新循环：
while (totalRead < length){
try {
numRead = inStream.read(b, 0, b.size)
if (numRead<=0)break
totalRead+=numRead
}catch (ae:ArrayIndexOutOfBoundsException) {
BluetoothService.log("end of file reached", ae)
}
if (BluetoothService.send(b, 0, numRead)){
Log.d(TAG, "totalRead: $totalRead\nlength: ${length.toInt()}")
notificationBuilder.setProgress(length.toInt(), totalRead, false)
notificationManager.notify(BTS_Constants.NOTIFICATION_ID, notificationBuilder.build())
}else{
BluetoothService.log("Error sending data", BluetoothServiceException())
}
}
并更新了发送功能：
@Synchronized fun send(bytes: ByteArray, offset: Int, length: Int):Boolean{
var synThread:ConnectedThread? = null
synchronized(this@BluetoothService){
synThread = mConnectedThread
}
var success:Boolean
try {
synThread?.write(bytes, 0, length)
success = true
}catch (e:Exception){
success = false
}
return success
}
更新写功能：
fun write(bytes: ByteArray, offset: Int, length: Int){
BluetoothService.log("writing bytes from $this")
outStream.write(bytes, offset, length)
outStream.flush()
BluetoothService.log("bytes written")
}
我注意到收到的照片属性中有一些有趣的东西。发送前文件的大小，以及收到文件的大小。发送的照片大小为5.05MB，收到后显示为526 MB。
答案 0 :(得分：0)
这应该是一个像
这样的循环while ( totalRead < length )
{
int numRead = inStream.read(b, 0, 1000000)
if ( numread <= 0 )
break;
totalRead += numRead;
int nsend = BluetoothService.send(b, 0, numRead);
if ( nsend != numRead )
well then you should make another loop here to send all
}
如果返回布尔值，则更像是
if (!BluetoothService.send(b, 0, numRead) )
{
// handle error
break;
}