PATCH method transformed to POST method

[alvico]

Somehow a PATCH request method is received as POST request method in the server:

Client Request:
2017-11-20 16:35:39 INFO Main:66 - "Body : {"status": "rejected"}"
"Headers : (5)"
Accept-Encoding : compress;q=0.5, gzip;q=1.0
Content-Type : application/json
Authorization : Basic ....
X-API-Version : v1
Accept : /

Server logs:
2017-11-20T16:35:39.81+0100 [RTR/0] OUT abit.apps.emea.vwapps.io - [2017-11-20T15:35:39.757+0000] "POST /data/feedback/11111-1111-111-1111-1111111 HTTP/1.1" 400 22 296 "-" "Java/1.8.0_131" "IP:PORT" "IP:PORT" x_forwarded_for:"someIP, someIP" x_forwarded_proto:"https" vcap_request_id:"someID" response_time:0.06272777 app_id:"someID" app_index:"1"

I'm totally lost about why is this happening, tried same thing with a GoLang framework and it worked fine.

[alvico]

Found out the problem by reading the documentation ... xD

The default client is HttpClient which is a thin wrapper over java.net.HttpUrlConnnection. java.net.HttpUrlConnnection does not support a PATCH method. HttpClient converts PATCH requests to a POST request and adds a X-HTTP-Method-Override: PATCH header. While this is a semi-standard industry practice not all APIs are configured to accept this header by default.

[vojkny]

For anyone who stumbles here – it can be hacked even without modifying current version of Fuel.

Two things need to be done:

1. Enable request.executionOptions.forceMethods = true
2. To allow for reflectively forcing PATCH to the string value on JDK11+, one must add JVM command line arguments: --add-opens java.base/sun.net.www.protocol.https=ALL-UNNAMED --add-opens java.base/java.net=ALL-UNNAMED