akka streams 1.0 and http routing - in java

[paweł kamiński]

hi,

probably again I ve overlooked it in documentation but I cannot find a way to respond to a http request with streamed response. probably HttpEntityChunked should be used but again I cannot figure out how to set entities and flows correctly.

this is basic example

private RouteResult getEvents(RequestContext ctx)
{

    final Source<Integer, BoxedUnit> source = producer.produce(10, 100);
    return ctx.complete(HttpResponse.create());
}

thanks for any hint on that

[Johannes Rudolph]

Hi paweł,

you are on the right track. You need to provide the data as a `Source<ByteString, Object>`. Then, you can create a response like this:

Source<ByteString, Object> data = ...
HttpResponse response = HttpResponse.create().withEntity(HttpEntities.createChunked(contentType, data));

If you know the length of the data (i.e. the aggregated number of octets in all the ByteStrings the Source provides), you can also use

HttpEntityies.create(contentType, length, data)

to create a (non-chunked) streamed default entity.

HTH
Johannes

[paweł kamiński]

aaaaah :]

thanks, I guess my bad was that I tried to use Source<T, BoxedUnit> and it wasnt accepted... and I was blind :))

[paweł kamiński]

OK I give up again :)

so if I have 

Source<Integer, BoxedUnit> source = producer.produce(10, 100);

and encoder that transforms integer to ByteStrings

final Flow<Integer, ByteString, BoxedUnit> encoder = Flow
        .of(Integer.class)
        .map(number -> {
            final ByteStringBuilder builder = new ByteStringBuilder();
            builder.putByte((byte) 4);
            builder.putInt(number, ByteOrder.BIG_ENDIAN);

            return builder.result();
        })
        .named("encoder");

I apply transformation as Source<ByteString, BoxedUnit> data = source.via(encoder) but how do I get Source<ByteString, Object> data.

Flow.of(Integer.class) creates Flow that materializes to BoxUnit

what Object stands for?

On Tuesday, 11 August 2015 09:44:15 UTC+2, Johannes Rudolph wrote:

[Johannes Rudolph]

Hi paweł,

yes, that's an unfortunate detail of the Java API. Whatever you put in
there as the Object value it will be ignored. So, to convert your flow
you should be able to use `.<Object>mapMaterializedValue(m -> m)` to
convert the type.

Johannes

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--
Johannes

-----------------------------------------------
Johannes Rudolph
http://virtual-void.net

[paweł kamiński]

that worked! you've saved my life again.