Provide a way to send a JSON object with WebClient

[karellen-kim]

Motivation: It would also be nice to have APIs that automatically convert a request body into bytestring and converts a response into an object.

Modifications:

• Add method ofJson in HttpRequest
• Add method aggregateAs in HttpResponse

Result:

• Closes #3707
• Users can convert a request body into bytestring automatically :

HttpRequest.ofJson(HttpMethod.POST, "/receiveContent", requestContent)

• Users can convert a response into an object automatically :

Content content = HttpResponse.of(MediaType.JSON_UTF_8, contentString)
                              .aggregateAs(Content.class)
                              .join(); 

ErrorMessage error = HttpResponse.of(MediaType.JSON_UTF_8, contentString)
                                 .aggregateAs(HttpStatusClass.SERVER_ERROR, ErrorMessage.class)
                                 .join();

ErrorMessage error = HttpResponse.of(MediaType.JSON_UTF_8, contentString)
                                 .aggregateAs(status -> status != HttpStatus.OK, ErrorMessage.class)
                                 .join();

Wrapper<Content> wrapperContent = HttpResponse.of(MediaType.JSON_UTF_8, contentString)
                                              .aggregateAs(new TypeReference<Wrapper<Content>>(){})
                                              .join();

[CLAassistant]

All committers have signed the CLA.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 35.38462% with 42 lines in your changes missing coverage. Please review.

Project coverage is 73.16%. Comparing base (829992a) to head (9a74a7b). Report is 1036 commits behind head on main.

Files	Patch %	Lines
...armeria/common/HttpUnsupportedStatusException.java	0.00%	14 Missing :warning:
...p/armeria/common/HttpResponseContentException.java	0.00%	12 Missing :warning:
...eria/common/HttpUnsupportedMediaTypeException.java	58.33%	8 Missing and 2 partials :warning:
.../java/com/linecorp/armeria/common/HttpRequest.java	60.00%	5 Missing and 1 partial :warning:

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #3757      +/-   ##
============================================
- Coverage     73.18%   73.16%   -0.03%     
- Complexity    16126    16133       +7     
============================================
  Files          1405     1408       +3     
  Lines         61669    61734      +65     
  Branches       7765     7771       +6     
============================================
+ Hits          45134    45165      +31     
- Misses        12612    12631      +19     
- Partials       3923     3938      +15     

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[ikhoon]

@karellen-kim I think #4021 takes over the features of this PR. Let me close this PR. 🙇‍♂️ I hope to see the next PR in the near future. 😆

[trustin]

But still we can't send a JSON object as it is, right? #4021 only takes care of the receiving part.

[ikhoon]

Ah, this PR includes HttpRequest.ofJson() also. I missed that. Let me reopen and continue to develop the sending part.

[ikhoon]

Gentle ping. @karellen-kim