JAXRS contract on API with @HeaderParam("Content-Type") and @Consumes with multiple values cause feign client build fail

[pdesoyres]

Version : 11.0

API :

    @POST
    @Path("/{stream:.+}")
    @Consumes({"application/xlsx", "text/csv"})
    @Produces("application/json")
    List<Integer> sourceFile(
            @PathParam("stream") String stream,
            @QueryParam("delimiterChar") @DefaultValue(",") String delimiterChar,
            @HeaderParam("Content-Type") String contentType,
            @RequestBody(required = true, description = "Input file") InputStream file
    ) throws IOException;

Calling API with :

myCtrl.sourceFile("stream", null, "text/csv", inputStream);

Causes the error :

java.lang.NullPointerException: null
	at feign.okhttp.OkHttpClient.toOkHttpRequest(OkHttpClient.java:64) ~[feign-okhttp-11.0.jar:na]
	at feign.okhttp.OkHttpClient.execute(OkHttpClient.java:168) ~[feign-okhttp-11.0.jar:na]
	at feign.SynchronousMethodHandler.executeAndDecode(SynchronousMethodHandler.java:119) ~[feign-core-11.0.jar:na]
	at feign.SynchronousMethodHandler.invoke(SynchronousMethodHandler.java:89) ~[feign-core-11.0.jar:na]
	at feign.ReflectiveFeign$FeignInvocationHandler.invoke(ReflectiveFeign.java:100) ~[feign-core-11.0.jar:na]
	at com.sun.proxy.$Proxy143.sourceFile(Unknown Source) ~[na:na]

Because at OkHttpClient:62 (mediaType = MediaType.parse(value);), value variable equals "application/xlsx, text/csv" instead of "text/csv".
Method MediaType.parse(value) returns null as "application/xlsx, text/csv" is not a valid media type.

[velo]

Hi,

By default, feign will only take the first media type from @Consumes
https://github.com/OpenFeign/feign/blob/master/jaxrs/src/main/java/feign/jaxrs/JAXRSContract.java#L117

Problem is you also overwriting it as parameter and that should take precedence.

But I expected feign to do that
https://github.com/OpenFeign/feign/blob/master/jaxrs/src/main/java/feign/jaxrs/JAXRSContract.java#L141

Are you able to create a unit test for JAXRSContract showing the issue?

[pdesoyres]

Hi,

you'll find the unit test illustrating this here : pdesoyres@ecc89e2

[velo]

@pdesoyres #1219

lemme know your thoughts on this fix.

[kdavisk6]

I think in this case Consumes should be translated into Accept and Produces translates into Content-Type. I’m not sure if we are doing that right.

In any case, the HeaderParam here is odd. There should be no need for it given the Produces and Consumes annotations.

The fix here should be accept more than one Consumes since is should map to Accept.

[velo]

@kdavisk6 image you are using the same interface for client and server...

For server, Consumes translates to Accept and Produce to Content-Type as you said.
But, on the client (feign) it needs to be the other way around.

[kdavisk6]

I understand that, but the JAXRS annotations don’t support multiple Produces values i feel like this came up before. What does our JAXRS library say about it?

[velo]

Au contraire my good friend. Both support many values

The way encoders/decoders work on jax-rs allow they to handle multiple just fine.

[kdavisk6]

Learn something every day...