在请求 OkHttp 中发送 JSON

Question

Friends!

I have a simple HTTP request:

void postRequest(String postUrl,String phone, String message) throws IOException {

    OkHttpClient client = new OkHttpClient();

    //RequestBody body = RequestBody.create(JSON, postBody);
    RequestBody body = new FormBody.Builder()
            .add("phone", phone)
            .add("message", message)
            .build();

    Request request = new Request.Builder()
            .url(postUrl)
            .post(body)
            .build();
    //System.out.println(request);

    client.newCall(request).enqueue(new Callback() {
        @Override
        public void onFailure(Call call, IOException e) {
            call.cancel();
        }

        @Override
        public void onResponse(Call call, Response response) throws IOException {
            Log.d("TAG",response.body().string());
        }
    });
}

How to properly implement sending a JSON object instead of simple parameters? My attempts were unsuccessful, so I really need a hint.

The server that will accept JSON is running on AKKA-HTTP. How do I send a request to this server correctly?

final case class Message(phone: String, message: String, service: String)
  implicit val item = jsonFormat3(Message)
  val queue: Queue[Message] = Queue()

val addMessage = post {
      path("add_message"){
        parameters("phone".as[String], "message".as[String], "service".as[String]){
          (phone, message, service) => {
            queue.enqueue(Message(phone, message, service))
            complete("ok")
          }
        }
      }
    }

Answer 1

The easiest way to map and serialize your object in JSON format is to use the ObjectMapper class of jackson-databind library.

I personally use it to implement integration tests of RestController s and it works very well. Here is the utility class I realized, you can take it and use it for your purposes:

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;

public final class JsonUtils {

    public static String json(Object obj) throws JsonProcessingException {
        ObjectMapper objectMapper = new ObjectMapper();
        return objectMapper.writeValueAsString(obj);
    }
}

What you need to have is a POJO class which implements Serializable , and then pass the instance of your class to the json method and it will return the JSON format.

You can definitely use it for Android projects. I found many examples where you can add the dependency, but it depends whether you use Gradle or Maven.

Try that out!!!

Answer 2

How do you like this option? I tried to implement it, but the send fails. I'm missing an important detail. But I don't understand what it is.

// create your json here
JSONObject jsonObject = new JSONObject();
try {
    jsonObject.put("KEY1", "VALUE1");
    jsonObject.put("KEY2", "VALUE2");
} catch (JSONException e) {
    e.printStackTrace();
}

  OkHttpClient client = new OkHttpClient();
  MediaType JSON = MediaType.parse("application/json; charset=utf-8");
  // put your json here
  RequestBody body = RequestBody.create(JSON, jsonObject.toString());
  Request request = new Request.Builder()
                    .url("https://YOUR_URL/")
                    .post(body)
                    .build();

  Response response = null;
  try {
      response = client.newCall(request).execute();
      String resStr = response.body().string();
  } catch (IOException e) {
      e.printStackTrace();
  }