BFScan

java -jar bfscan.jar <jar_war_apk> <...> [-m <mode>] [-ma <minifiedAnnotationsSupport>] [-r <mappingFile>] [-s <searchString>] [-u <url>] [-v <verbose>]

 -m <mode>                          Mode ([a]ll, [s]ecrets, [h]ttp), default: all
 -ma <minifiedAnnotationsSupport>   Minified or unknown annotations support (yes, no), default: yes
 -r <mappingFile>                   Deobfuscation mapping file
 -s <searchString>                  Search string
 -u <url>                           API base url (http://localhost/api/)
 -v <verbose>                       Log level (off, error, warn, info, debug, trace)

java -jar bfscan.jar test/*.apk -u https://example.tld/api/

@RestController
@RequestMapping("/api")
public class UserController {

    @PostMapping("createUser")
    public String create(@RequestParam Optional<String> someParamName, @RequestBody User user) {
        return "response";
    }

POST /api/createUser?someParamName=value HTTP/1.1
Host: localhost
Connection: close
Content-Type: application/json

{
  "name": "name",
  "age": 1
}

java -jar BFScan.jar ./tests/example.apk -r ./tests/mapping.txt