Question

This is more like a matter of conscience than a technological issue :p
I’m writing some java code to dowload files from a server…For that, i’m using the BufferedOutputStream method write(), and BufferedInputStream method read().

So my question is, if i use a buffer to hold the bytes, what should be the number of bytes to read? Sure i can read byte to byte using just int byte = read() and then write(byte), or i could use a buffer. If i take the second approach, is there any aspects that i must pay attention when defining the number of bytes to read\write each time? What will this number affect in my program?

Thks

Answer 1

Unless you have a really fast network connection, the size of the buffer will make little difference. I’d say that 4k buffers would be fine, though there’s no harm in using buffers a bit bigger.

The same probably applies to using read() versus read(byte[]) … assuming that you are using a BufferedInputStream.

Unless you have an extraordinarily fast / low-latency network connection, the bottleneck is going to be the data rate that the network and your computers’ network interfaces can sustain. For a typical internet connection, the application can move the data two or more orders of magnitude of times faster than the network can. So unless you do something silly (like doing 1 byte reads on an unbuffered stream), your Java code won’t be the bottleneck.