FileOutputStream fileStream = new FileOutputStream(filename.getName());
while (totalRead < size) {
if (size - totalRead > CHUNKSIZE) {
read = getInputStream().read(buffer,CHUNKSIZE);
} else {
read = getInputStream().read(buffer,size - totalRead);
}
totalRead += read;
fileStream.write(buffer,read);
fileStream.flush();
if (System.currentTimeMillis() > nextPrint) {
nextPrint += 1000;
int speed = (int) (totalRead / (System.currentTimeMillis() - startTime));
double procent = ((double)totalRead / size) * 100;
gui.setStatus("Reciving: " + filename + " at " + speed + " kb/s," + procent + "% complete");
}
}
gui.setStatus("Reciving: " + filename + " complete.");
fileStream.close();
FileOutputStream.close在接收大文件时花了很长时间,为什么呢？正如你所看到的那样,我正在每个收到的大块上冲洗流.
最佳答案
根据操作系统的不同,flush()不再强制将数据写入操作系统.在FileOutputStream的情况下,write()将所有数据传递给OS,因此flush()不执行任何操作.其中close()可以确保文件实际写入磁盘(或不依赖于操作系统).您可以在写入数据时查看磁盘是否仍处于忙碌状态.
一个500 MB的文件需要30秒,这意味着你写的是17 MB / s.这听起来像一个非常慢的磁盘或网络共享/驱动器中的文件.
你可以试试这个
File file = File.createTempFile("deleteme","dat"); // put your file here.
FileOutputStream fos = new FileOutputStream(file);
long start = System.nanoTime();
byte[] bytes = new byte[32 * 1024];
for (long l = 0; l < 500 * 1000 * 1000; l += bytes.length)
fos.write(bytes);
long mid = System.nanoTime();
System.out.printf("Took %.3f seconds to write %,d bytes%n",(mid - start) / 1e9,file.length());
fos.close();
long end = System.nanoTime();
System.out.printf("Took %.3f seconds to close%n",(end - mid) / 1e9);
版画
Took 0.116 seconds to write 500,006,912 bytes
Took 0.002 seconds to close
你可以从速度上看到,即使在收盘时,它也不会写入数据.即驱动器不是那么快.
