Content Type being append with charset=ISO-8859-1

Hello!

I’m updating a Spring Boot 2.2 app with Spring Cloud Hoxton.SR1 to Spring Boot 2.3 with Hoxton.SR5, and the provider tests started to fail. The test fail with the following message:

DefaultHandlerExceptionResolver : Resolved [org.springframework.web.HttpMediaTypeNotSupportedException: Content type 'application/json;charset=ISO-8859-1' not supported]

Something is appending the charset=ISO-8859-1 to the Content-Type header, even tho our contract DSL sets it to application/json only:

Contract.make {
    description 'create something'
    request {
        method POST()
        url '/something'
        body(
            property: 'value'
        )
        headers {
            contentType(applicationJson()) // This is "application/json"
        }
    }
    response {
        status OK()
    }
}

I think UTF-8 is the default for Spring Boot 2.2 onward, so it was not necessary anymore to use applicationJsonUtf8() as content type. If I do change the content type to applicationJsonUtf8(), then that charset=ISO-8859-1 is not appended and the test pass.

Is appending a default charset an expected behavior for Spring Cloud Contract?

Best regards, Rafael Pacheco.

[LiaminRoman]

Hi all, I had a simial issue, here my investigations: Spring Boot 2.3 uses Spring-web 5.2.7, (Spring Boot 2.2 used Spring-Web 5.2.6) Spring-web v.5.2.7 has a class AbstractJackson2HttpMessageConverter and it was modified - it started to check encoding for Json body (canRead(@Nullable MediaType mediaType)), so now only null encodign or UTF-xx supported.

On other hand RestAssured (3.3 in my case) by default uses ISO_8859_1 as defaultContentCharset (see deafult constructor of RestAssuredMockMvcConfig -> new EncoderConfig()) and if you don’t specify any charset excplisitly in the request content-type - it will add the defalt one.

So Spring Boot 2.3 (Spring Web 5.2.7) becomes more strict to headers.

My solution was to bring custom configuration to RestAssured: RestAssuredMockMvc.config = new RestAssuredMockMvcConfig() .encoderConfig(new EncoderConfig(UTF_8.name(), UTF_8.name()));

or opt-out appending of default content charset: EncoderConfig encoderConfig = new EncoderConfig() .appendDefaultContentCharsetToContentTypeIfUndefined(false); RestAssuredMockMvcConfig restAssuredConf = new RestAssuredMockMvcConfig() .encoderConfig(encoderConfig); RestAssuredMockMvc.config = restAssuredConf;

[marcingrzejszczak]

Indeed until Boot bumps Rest Assured to 4.x I guess we need to do

		EncoderConfig encoderConfig = new EncoderConfig().appendDefaultContentCharsetToContentTypeIfUndefined(false);
		RestAssuredMockMvc.config = new RestAssuredMockMvcConfig().encoderConfig(encoderConfig);