Re: Non-Blocking Socket and BufferedInputStream

From:

Knute Johnson <nospam@rabbitbrush.frazmtn.com>

Newsgroups:

comp.lang.java.programmer

Date:

Fri, 29 Dec 2006 15:21:56 -0800

Message-ID:

<pqhlh.20882$4w4.4602@newsfe13.lga>

mshetty@mail.com wrote:

Hi,

We are new to Java. We are using some exising code which does a
byte-by-byte read from the socket. The data that is being read is an
xml string. A byte-by-byte read takes about 150 to 200 milliseconds. We
need to improve the response time.

How much data are you reading in 200 ms?

The application uses BufferedInputStream's read method to read the
data. On the net we found some sites which suggested doing read in
chunks (read an array of bytes).
Looping until read returns -1 does not work as read block which the
data read is complete.

The -1 is for when the end of stream has been reached, for example you
attempt to read one more byte than exists in a file. You said you were
reading from a socket? Is the server closing when you've sent all the
data you want to send? If it is you will throw an IOException in the
read and -1 never comes into play.

As per the documentation the read API should return -1 if there is no
data.

Probably not.

Similarly DataInputStream's readFully also blocks.

Is there a non-blocking way of doing a read in Java?

Would help if you suggest some alternative.

Can you do any more work if you don't have all the data? If not I would
just play with the buffer size of the BufferedInputStream. It is
capable of very fast I/O. What is the size of the buffer now?

--

Knute Johnson
email s/nospam/knute/