program hangs inside while loop for reading input stream from socket: Java

Question

I have the following code to read an input stream from a socket connection:

private ByteBuffer toByteBuffer(BufferedInputStream is) throws IOException {
    ByteArrayOutputStream buffer = new ByteArrayOutputStream();
    int l;
    byte[] data = new byte[256];
    while ((l = is.read(data, 0, data.length)) != -1) {
        buffer.write(data, 0, l);
    }
    buffer.flush();
    return ByteBuffer.wrap(buffer.toByteArray());
}

In the first iteration of the while loop, everything goes fine and I am able to get the data into the buffer. But then it gets stuck at while ((l = is.read(data, 0, data.length)) != -1) {

I think (and I might be wrong) it is because it is waiting for more data from the socket, which is never going to come.

How do I handle this situation/hang?

gprathour · Accepted Answer · 2014-07-08 11:20:50Z

4

As the BufferedInputStream method you are using does not block you get the situation that as soon as your InputStream does not have any data and is not closed you don't get a -1 but a 0. This will send your method into an endless loop.

So for reading local streams it is better to check for read() <= 0 as you usually get the data fast enough.
The best way is to make sure there is an eof by closing the stream.

edited Jul 8, 2014 at 11:20

gprathour

15.4k5 gold badges72 silver badges92 bronze badges

answered Jul 7, 2014 at 20:46

Dawnkeeper

2,8831 gold badge28 silver badges42 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

program hangs inside while loop for reading input stream from socket: Java

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related