feign.httpclient.ApacheHttpClient should not setEntity when request body is null in order to support application/x-www-form-urlencode

In recently, I replaced “com.netflix.feign:feign-httpclient:8.18.0” with “io.github.openfeign:feign-httpclient” along with spring boot application, because which from netflix is deprecated.

I found a difference between two dependencies that one from netflix let entity null on building request, the other from openfeign(this repo.) let entity be an empty byte array.

So, org.apache.http.client.methods.RequestBuilder comes to finally build a HttpUriRequest of InternalRequest skipping making entityCopy be UrlEncodedFormEntity, even if headers has ‘Content-Type: application/x-www-form-urlencoded’.

So I finally got 400 Bad Request from other spring cloud server.

I think, as a wrapper of apache http client, feign.httpclient should follow apache’s implementation.

[kdavisk6]

From what I can tell looking into this, the issue lies with our use of the RequestBuilder, which explicitly states:

Please note that this class treats parameters differently depending on composition of the request: if the request has a content entity explicitly set with setEntity(org.apache.http.HttpEntity) or it is not an entity enclosing method (such as POST or PUT), parameters will be added to the query component of the request URI. Otherwise, parameters will be added as a URL encoded entity.

Since you appear to be one of a few with this issue, I suspect the issue is in your implementation. Can you please provide a test case the replicates your issue?

[starrybleu]

I found it has conflict with #510, #511. But after failed to test, dug into the RequestBuilder. Test of withoutBody should be done along without @PUT or @POST.