#1192 check null before use this.content

[npeters]

test + code.

This code fix the NPE

[npeters]

this PR is linked to aws/serverless-java-container#1085.

when both will be merge.
it should work fine

@PostMapping(path = "/echo")
    public ResponseEntity<String> get(@RequestBody String body,
                                      @RequestHeader Map<String, String> headers,
                                      HttpServletRequest req) {


        return ResponseEntity.ofNullable(body);
    }

[olegz]

Thank you for your contribution, but. . .
Please run the build, there are checkstyle violations related to code formatting

[npeters]

ok, I followed the contribution guide https://github.com/spring-cloud/spring-cloud-build/tree/main
the commit is much cleaner ;)