Read all bytes from socket Stops at 52964 bytes

Question

I'm making a Server that gets packages at 64 kb size.

        int length = 65536;
        byte[] bytes = new byte[length];

        int pos = 0;
        while(pos < length -1)
        {
            System.out.println("Before read");
            pos += dis.read(bytes, pos, length-pos);
            System.out.println(""+pos+" >> "+ length);
        }

This is the code I use to read all bytes from the socket. Dis is a InputStream. When I run the code 1 out of n goes wrong. The code only receives 52964 bytes instead of 65536 bytes.

I also checked the C code and it says it send 65536 bytes.

Does someone know what I'm doing wrong?

I don't see how this happens as you are not getting `-1` for EOF either I assume. What are you getting, an Exception? — Peter Lawrey, Jan 10 '13 at 14:25
Not the main problem, but your loop skips the last byte, use `while(pos < length)` — Henry, Jan 10 '13 at 14:27

score 2 · Accepted Answer · edited Sep 11 '14 at 08:24

2

This is yet another case where Jakarta Commons IOUtils is a better choice than writing it yourself. It's one line of code, and it's fully tested. I recommend IOUtils.readFully() in this case.

If it does not read the entire buffer, then you know that you're not sending all the content. Perhaps you're missing a flush on the server side.

edited Sep 11 '14 at 08:24

Riduidel

22,052
14
85
185

answered Jan 10 '13 at 14:29

parsifal

1,645
9
6

score 1 · Answer 2 · answered Jan 10 '13 at 14:28

InputStream.read() returns the number of bytes read or -1 if the end of the stream has been reached. You need to check for that error condition. Also, I suspect your while(..) loop is the problem. Why are you calling it pos as in position? You may be terminating prematurely. Also, ensure that your C code, whatever it is doing, is sending properly. You can examine the network traffic with a tool like Wireshark to be sure.

score 0 · Answer 3 · answered Jan 10 '13 at 14:26

What do you mean it "goes wrong"? What is the output? It can't be exiting the loop before reading the full 64 KB, so what really happens?

Also, it's better to save the return value of the I/O call separately and inspect it, before assuming the I/O was successful. If that's DataInputStream.read(), it returns -1 on error.

score 0 · Answer 4 · answered Jan 10 '13 at 20:56

0

Your code is incorrect as it doesn't check for -1.

This is a case for using DataInputStream.readFully() rather than coding it yourself and getting it wrong.

answered Jan 10 '13 at 20:56

user207421

305,947
44
307
483

Read all bytes from socket Stops at 52964 bytes

4 Answers4