Retrofit 2.0 throwing "IllegalArgumentException: @Field parameters can only be used with form encoding". How to do right API query and fix it?

Question

My problem is that I don't know how to start using Retrofit 2.0 with received API - mentioned below...

Firstly, I need to username, password, fbID (optional), gmailID (optional), twitID (optional), gender, birthDate, location (not required - if long and lat has values), longitude (optional), latitude (optional), profileImage (optional).

When all parameters are good - receive status = true. If not - receive status = false and required parameters which are wrong (e.g. mail is already taken)

So I can receive status = true or status = false and array with max 5 parameters (username, email, password, gender, birthDate).

I tried this API Interface:

public interface AuthRegisterUserApi {     @PUT()     Call<AuthRegisterUserModel> getStatus(             @Field("username") String username,             @Field("email") String email,             @Field("password") String password,             @Field("fbID") String fbID,             @Field("gmailID") String gmailID,             @Field("twitID") String twitID,             @Field("gender") String gender,             @Field("birthDate") String birthDate,             @Field("location") String location,             @Field("longitude") String longitude,             @Field("latitude") String latitude,             @Field("profileImage") String profileImage             );      class Factory {         private static AuthRegisterUserApi service;          public static AuthRegisterUserApi getInstance() {             Retrofit retrofit = new Retrofit.Builder()                     .baseUrl(ApiConstants.REGISTER_URL)                     .addConverterFactory(GsonConverterFactory.create())                     .build();              service = retrofit.create(AuthRegisterUserApi.class);              return service;         }     } } 

with this API models (Pastebin.com)

and this code in Activity:

AuthRegisterUserApi.Factory.getInstance()         .getStatus(                 usernameEditText.getText().toString(),                 emailEditText.getText().toString(),                 passwordEditText.getText().toString(),                 "", "", "",                 (maleRadioButton.isChecked() ? "male" : "female"),                 mYear + "-" + mMonth+1 + "-" + mDay,                 (geoLocationToggleButton.isChecked() ? geoLocationEditText.getText().toString() : ""),                 (!geoLocationToggleButton.isChecked() ? "50" : ""),                 (!geoLocationToggleButton.isChecked() ? "50" : ""),                 "")         .enqueue(new Callback<AuthRegisterUserModel>() {     @Override     public void onResponse(Call<AuthRegisterUserModel> call, Response<AuthRegisterUserModel> response) {         if(response.isSuccessful()) {             if (response.body().isStatus()) {                 showToast(getApplicationContext(), "Registration ok.");             } else {                 response.body().getInfo().getUsername();             }         }     }      @Override     public void onFailure(Call<AuthRegisterUserModel> call, Throwable t) {      } }); 

I have error: java.lang.IllegalArgumentException: @Field parameters can only be used with form encoding. (parameter #1) for method AuthRegisterUserApi.getStatus

I tried to register user using Postman and it works when I used option Body -> x-www-form-urlencoded.

How can I create I register query to this API? Change @Field to something else? I have got this error always...

EDIT: Need to change API Interface to this:

public interface AuthRegisterUserApi {     @FormUrlEncoded     @PUT("/api/register")     Call<AuthRegisterUserModel> getStatus(             @Field("username") String username,             @Field("email") String email,             @Field("password") String password,             @Field("fbID") String fbID,             @Field("gmailID") String gmailID,             @Field("twitID") String twitID,             @Field("gender") String gender,             @Field("birthDate") String birthDate,             @Field("location") String location,             @Field("longitude") String longitude,             @Field("latitude") String latitude,             @Field("profileImage") String profileImage             );      class Factory {         private static AuthRegisterUserApi service;          public static AuthRegisterUserApi getInstance() {             Retrofit retrofit = new Retrofit.Builder()                     .baseUrl(ApiConstants.BASE_URL)                     .addConverterFactory(GsonConverterFactory.create())                     .build();              service = retrofit.create(AuthRegisterUserApi.class);              return service;         }     } } 

BASE_URL = http://ip_address:8400 for me...

But still got error: Response.rawResponse = Response{protocol=http/1.1, code=400, message=Bad Request, url=http://ip_address:8400/api/register}. Using Postman with the same data I received code=201 Created. Don't know why...

Answer 1

you just missed @FormUrlEncoded above your Rest method call.