Android multithreading download speed is very slow, why is the application market on the market downloading speed very fast

  android, question

Write your own application market and download apk files with multi-threads, but the download speed is very slow (not a problem of network speed), while files in the application market on the market are very fast, which is Why?.
accessFile = new RandomAccessFile(file, “rwd”);
Seek (startpos plus completeSize); //Set where to write data
inputStream = connection.getInputStream();
byte[] buffer = new byte[4096];
int length = -1;
while ((length = inputStream.read(buffer)) ! = -1) {

//write data
 accessFile.write(buffer, 0, length);
 //Accumulate the downloaded length
 CompleteSize = completeSize plus length;

bracket
Byte[4096] is set to byte[4096*1000], but at most 8192 is Why? ? ?

There may be a problem with your multithreading, you can Log yourself to see the amount of data downloaded by each thread.