Introduce addSupportedMediaTypes() in FormHttpMessageConverter

[sbrannen]

Status Quo

Although it is currently possible to add a custom supported MediaType to FormHttpMessageConverter, it is a bit cumbersome since the List returned by getSupportedMediaTypes() is immutable, which leads to code similar to the following.

FormHttpMessageConverter converter = // ...
List<MediaType> supportedMediaTypes = new ArrayList<>(converter.getSupportedMediaTypes());
supportedMediaTypes.add(new MediaType("text", "custom-type"));
converter.setSupportedMediaTypes(supportedMediaTypes);

Proposal

It would be great if adding a custom media type was as simple as the following, where addSupportedMediaTypes() accepts a var-args list.

FormHttpMessageConverter converter = // ...
converter.addSupportedMediaTypes(new MediaType("text", "custom-type"));

Related Issues

• Support multipart/related and multipart/mixed MediaTypes in RestTemplate #23159

Deliverables

• Introduce addSupportedMediaTypes(MediaType...) in FormHttpMessageConverter.