Question

I have strange problem with receiving data from socket.
On client im using air socket. On server java netty.
Im writing to socket simple packets: int numPacket, int textLength, utf8String text. And read on client.

//server
buffer.writeInt( packetId );
ChannelBuffer ch = ChannelBuffers.copiedBuffer( text, CharsetUtil.UTF_8);
buffer.writeInt( text.length() );
buffer.writeBytes(ch);

//client
packetId = socket.readInt()
packetLen = socket.readInt()
text = socket.readUtfBytes(packetLen)

Sometimes one packets() doesnt receives by client, but server was send there, and tcpdump show that packet was send. If server send new packet, client read previous packet, and doesn’t receivs new packet – and it’s works like queue that im don’t need.
p.s sorry for bad english -_-

Answer 1

Looks like client maybe waiting for some byte \n,\u etc to know the end of frame. I had similar problem with flash because the client was expecting a null byte at the end of the the transmission.

You could try to add the following sort of encoder as the last encoder in your pipeline and give it a try. The relevant code for handling nul byte is shown below.

    ChannelBuffer nulBuffer = ChannelBuffers.wrappedBuffer(new byte[] { 0 });
    ChannelBuffer buffer = ChannelBuffers.wrappedBuffer((ChannelBuffer)msg,nulBuffer);