Why doesn't http client in editor combine a form POST with a query string?

I'm using verson 2018.2.1.

Example:

POST http://localhost:80/myweb/hello/
  ?name=John
Content-Type: multipart/form-data; boundary=WebAppBoundary

--WebAppBoundary
Content-Disposition: form-data; name="field-name"

field-value
--WebAppBoundary--

The Fiddler shows:

POST http://localhost:80/myweb/hello/ HTTP/1.1
Content-Type: multipart/form-data; boundary=WebAppBoundary
Content-Length: 171
Host: localhost:80
Connection: Keep-Alive
User-Agent: Apache-HttpClient/4.5.5 (Java/1.8.0_152-release)
Accept-Encoding: gzip,deflate

--WebAppBoundary
Content-Disposition: form-data; name="field-name"
Content-Type: */*; charset=UTF-8
Content-Transfer-Encoding: 8bit

field-value
--WebAppBoundary--

The ?name=John has gone.

How to resolve it?