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Re: Problem with netty4:udp and udpByteArrayCodec=true


Hi Ron,
I'm far from an expert on Netty, it seems to me like that
`convertBodyTo(String.class, "UTF-8")` will lead to issues with binary
data.

What you want (I think) is
`.to("netty4:udp://host:port?allowDefaultCodec=false&useByteBuf=true")`
without `convertBodyTo`

zoran


On Fri, Nov 9, 2018 at 6:12 AM, Ron Cecchini <roncecchini@xxxxxxxxxxx> wrote:
>
> First, a couple of thank yous several weeks in the making:
>
> Thank you to Claus (as always) for help regarding replacing camel-rabbitmq with a custom class.  Indeed, I only needed to do a write.  So using 'to("bean:myBean?method=process)' worked perfectly.
>
> Thank you to Zoran for advice on Spring injection vs. Component Scan.  I never was able to get beans in the Spring config auto-wired, so I had to do the manual steps of getting the Spring context, getting the bean, and then setting the bean where it needed to be.  A bit ugly, but only a few lines of code.  It works, so I'm leaving it alone for now.
>
> Now on to my most recent hurdle...
>
> I'm trying to write a protobuf over UDP to a server (a non-Camel app written in C++) expecting it serialized into a byte array.
>
> The problem is that the only write that makes it to the server seems to be serialized incorrectly.  Conversely, when I think I've correctly serialized it, nothing seems to get written to the wire.
>
> The route below is the one that makes it to the server.  When I do a tcpdump on the server's side, however, I can see that the payload is about 35-40 bytes bigger than what the protobuf says its serialized size should be:
>
> from("direct:protobuf")
>      .marshal().protobuf()
>      .convertBodyTo(String.class, "UTF-8")  // needed, else to(netty4:udp) hangs
>      .to("netty4:udp://host:port?udpConnectionlessSending=true&sync=false");
>
> I immediately recognized this as probably being a "default codec" problem, similar to what I recently encountered when I was writing some JSON over UDP with netty4.
>
> So I tried the following, but nothing was written over the wire:
>
>      .to("netty4:udp://host:port?udpConnectionlessSending=true&sync=false&allowDefaultCodec=false");
>
> I tried about a half dozen combinations: marshalling / not marshalling, convertBodyTo() / no convertBodyTo(), allowDefaultCode = false / true, etc.
>
> Nothing was working.  And then I somehow stumbled upon 'udpByteArrayCodec' in the docs and thought I'd found it!
>
> However, this didn't send anything to the wire either:
>
>      .to("netty4:udp://host:post?udpConnectionlessSending=true&sync=false&udpByteArrayCodec=true");
>
> Neither did this:
>
>      .to("netty4:udp://host:port?udpConnectionlessSending=true&sync=false&udpByteArrayCodec=true&allowDefaultCodec=false");
>
> Only the original route resulted in *anything* being written across the wire for the server to see:
>
>      .to("netty4:udp://host:port?udpConnectionlessSending=true&sync=false");
>
> Does anyone know what else I should try?
>
> I have never had any luck trying to install a non-default encoder/decoder, but in this case I don't think I even need it.  I just need to serialize the protobuf to a byte array, and it seems that this 'udpByteArrayCodec' is exactly what I need.  So how should I be using it?  What could be preventing anything from appearing over the wire?
>
> Thank you so much as always!
>
> Ron



-- 
Zoran Regvart