How to create a Vert.x ReadStream from an InputStream

Question

I would like to stream the stdout of a local process to a Vert.x HttpResponse.

To do it I think I have to stream/convert/pipe a java.io.InputStream (which streams the process stdout) to an io.vertx.core.streams.ReadStream and then I can pipe the ReadStream to the HttpResponse.

I'm searching for a solution that has a small memory impact, so read the whole stdout in memory and then flush it to the HttpResponse is not possible.

Thanks

Not sure what are you trying to achieve by that. ReadStream represent large, but finite amount of data. `System.out` is an infinite stream. The result would be that your HttpResponse never closes. — Alexey Soshin, Feb 12 '21 at 15:38
I think OP wants to start a process (e.g. via ProcessBuilder) and pipe the output to the HttpResponse rather than piping System.out to the HttpResponse — Selim, Feb 13 '21 at 20:35

score 3 · Accepted Answer · answered Feb 13 '21 at 01:45

Check out:

https://gist.github.com/Stwissel/a7f8ce79785afd49eb2ced69b56335de

Here is how I used it:

InputStream is = ...
          AsyncInputStream ais = new AsyncInputStream(
            vertx, vertx.getOrCreateContext(), is);
          ais.pipeTo(response);

score 2 · Answer 2 · answered Aug 01 '21 at 11:23

2

Another way is to use the OutputToReadStream class from the vertx-java.io library (I am the author):

new OutputToReadStream(vertx).wrap(inputStream).pipeTo(response);

answered Aug 01 '21 at 11:23

Guss

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How to create a Vert.x ReadStream from an InputStream

2 Answers2