Spring Rest Client, automatically set content-length of body on put/post

Put call that fails with 400:

restClient.put()
                .uri("/tickets/$ticketId")
                .contentType(MediaType.APPLICATION_JSON)
                .body(CloseTicketRequest())
                .retrieve()
                .body(String::class.java)

I already had "equivalent" code in python using requests library, so was a bit surprised.

When inspecting the HTTP request I noticed that the RestClient do not add the content-length automatically, while the requests library did that.

When missing, I get 400 bad request from the server.

I propose either:

1. always automatically add content-length
2. instead of or in addition of having a .contentLength() method, why not just have an option to set it automatically, why should I convert my payload to json and getting its length "manually"?

Comment From: bclozel

This is called out in the upgrade guide here.

Comment From: gregjotau

Thanks, that worked, adding this for others: // Most implementations of ClientHttpRequestFactory do not buffer request bodies before sending them to the server. // This means the Content-Length is not set, which Gorgias does not support for put requets. private final val bufferingFactory: BufferingClientHttpRequestFactory = BufferingClientHttpRequestFactory(SimpleClientHttpRequestFactory()) private val restClient = RestClient.builder() .defaultHeaders { it.setBasicAuth(apiUsername, apiToken) }.baseUrl("https://$subdomain.gorgias.com/api") .requestFactory(bufferingFactory) .build()