title: How to set "Content-type" header in RestEasy Client framework using a proxy interface?
body: <p>I am using Resteasy client proxy framework to talk to a REST API. I have defined some methods on the proxy interface but unfortunately, I have some issues related to <strong>Content-Type</strong> not being set properly when sending http requests, which gives me an <strong>http 400 (Bad Request) error code</strong> since the remote API is expecting the <strong>Content-type</strong> header param to be <strong>application/json</strong>.</p>
  
  <p>Here is how it looks like :</p>
  
  <pre><code>@Path("/")
  public interface RestAPIClient {
  
    @POST
    @Path("/send")
    String send(@CookieParam("token") String token, @FormParam("name") String id, @FormParam("message") String message, @FormParam("emails") List&lt;String&gt; emails);
  
  }
  </code></pre>
  
  <p>is there a way to set the "Content-type" header as "application/json" directly at the proxy interface level ? using some annotations maybe ?</p>
  
  <p>thanks</p>