我正在尝试在我的Android应用程序中执行一个AsyncTask类,以分析网络连接速度,包括下载和上传。目前我正在处理下载部分,但是我得到的结果与我期望的结果不符。我在一个Wifi网络上进行测试,该网络始终获得15Mbps的下载/上传速度,但是我的应用程序得到的结果只有大约1Mbps左右。当我在设备上运行速度测试apk时,得到的结果约为3.5Mbps。这个函数可以工作,但似乎只有应该有一半的速度。以下代码是否能产生准确的结果?
try {
String DownloadUrl = "http://ipv4.download.thinkbroadband.com:8080/5MB.zip";
String fileName = "testfile.bin";
File dir = new File (context.getFilesDir() + "/temp/");
if(dir.exists()==false) {
dir.mkdirs();
}
URL url = new URL(DownloadUrl); //you can write here any link
File file = new File(context.getFilesDir() + "/temp/" + fileName);
long startTime = System.currentTimeMillis();
Log.d("DownloadManager", "download begining: " + startTime);
Log.d("DownloadManager", "download url:" + url);
Log.d("DownloadManager", "downloaded file name:" + fileName);
/* Open a connection to that URL. */
URLConnection ucon = url.openConnection();
//Define InputStreams to read from the URLConnection.
InputStream is = ucon.getInputStream();
BufferedInputStream bis = new BufferedInputStream(is);
//Read bytes to the Buffer until there is nothing more to read(-1).
ByteArrayBuffer baf = new ByteArrayBuffer(1024);
int current = 0;
while ((current = bis.read()) != -1) {
baf.append((byte) current);
}
long endTime = System.currentTimeMillis(); //maybe
/* Convert the Bytes read to a String. */
FileOutputStream fos = new FileOutputStream(file);
fos.write(baf.toByteArray());
fos.flush();
fos.close();
File done = new File(context.getFilesDir() + "/temp/" + fileName);
Log.d("DownloadManager", "Location being searched: "+ context.getFilesDir() + "/temp/" + fileName);
double size = done.length();
if(done.exists()) {
done.delete();
}
Log.d("DownloadManager", "download ended: " + ((endTime - startTime) / 1000) + " secs");
double rate = (((size / 1024) / ((endTime - startTime) / 1000)) * 8);
rate = Math.round( rate * 100.0 ) / 100.0;
String ratevalue;
if(rate > 1000)
ratevalue = String.valueOf(rate / 1024).concat(" Mbps");
else
ratevalue = String.valueOf(rate).concat(" Kbps");
Log.d("DownloadManager", "download speed: "+ratevalue);
} catch (IOException e) {
Log.d("DownloadManager", "Error: " + e);
}
示例输出
10-08 15:09:52.658: D/DownloadManager(13714): download ended: 70 secs
10-08 15:09:52.662: D/DownloadManager(13714): download speed: 585.14 Kbps
感谢您提前的帮助。如果有更好的方法,请告诉我。
size
、endTime
和startTime
都是整数,就像1024、1000和8一样,因此在转换为长整型之前,计算是以整数形式进行的(这可能会导致不精确的测量结果,但并不是您观察到的巨大差异的原因)。 - njzk2