title: spring webclient sign a body request
body: <p>I am in the need to sign a body request send out with WebClient in Spring.</p>
  
  <p>Now, the problem it's that i am not able to get the body in "raw" way (the exact body that get sent to remote server) and calculate the signature from this body.</p>
  
  <p>I have two scenario, a post of an object and post a FormData.
  on the 1st i can probably use an ObjectMapper, to mimic what WebClient does (till WebClient change it, and everything break) but for FormData, mimic it will be tricky. </p>
  
  <p>If i send
  a = b, e = x
  i have to deal with encoding, and order of parameter (from http point of view) it's not mandatory so a=b, e=x it's the same of e=x,a=b but that's not true for a signature where sha1(string) change</p>
  
  <p>With filter i get the body() but it's a BodyInserter and it doesn't seems that it can be converted into a String or byte[]</p>