title: Sending JSON requests using content-type text/plain
body: <p>I saw there are several related posts, but none really answered my questions. </p>
  
  <p>To be specific, let's say there are some middle layers in front of the request handlers (e.g. web server, Spring framework, Jersey framework, etc). The request handler explicitly announced that it expects a JSON request.</p>
  
  <p>Question 1 - if the client sends a valid JSON request, but set the content-type to be text/plain, is it valid situation for the middle layers NOT to deliver the request to the request handler because of the content-type?</p>
  
  <p>Question 2 - if the client sends a valid JSON request and using content-type application/json, and the request handler announces that it will parse the JSON request by itself. Can I assume some real world implementations of the middle layers will still verify the request before passing it to the request handler? (in other words - is it valid to assume that application/json may cause performance loss?)</p>