Android Retrofit - POST request doesn't work,

This is the error I'm getting:

com.google.gson.JsonSyntaxException: java.lang.IllegalStateException: Expected BEGIN_OBJECT but was STRING at line 1 column 1 path $

JSON response I'm getting from Postman:

{
  "title": "test title",
  "body": "test body",
  "userId": 1,
  "id": 101
}

This is how I echoed the response from the rest API (used slim2 framework):

$app->post('/posts', function() use($app){
    $res = array(
        "title" => $app->request->post('title'),
        "body" => $app->request->post('body'),
        "userId" => 1,
        "id" => 101
        );
    echoResponse(201, $res);
});

echoResponse method:

function echoResponse($status_code, $response) {
    $app = \Slim\Slim::getInstance();
    $app->status($status_code);
    $app->contentType('application/json');

    echo json_encode($response);
}

The method where I call the API:

public void sendPost(String title, String body) {
    mAPIService.savePost(title, body, 1).enqueue(new Callback<Post>() {
        @Override
        public void onResponse(Call<Post> call, Response<Post> response) {
            Log.i(TAG, "post sendPost to onResponse.");
            if(response.isSuccessful()) {
                showResponse(response.body().toString());
                Log.i(TAG, "post submitted to API." + response.body().toString());
            }
        }

        @Override
        public void onFailure(Call<Post> call, Throwable t) {
            Log.e(TAG, "Unable to submit post to API.");
            Log.e(TAG, t.toString());
        }
    });
}

The APIServie interface:

public interface APIService {
@POST("/posts")
@FormUrlEncoded
Call<Post> savePost(@Field("title") String title,
                    @Field("body") String body,
                    @Field("userId") long userId);
}

How I got the retrofit instance:

mAPIService = ApiUtils.getAPIService();
public class ApiUtils {
    private ApiUtils() {}
    public static final String BASE_URL = "http://myurl/v1/";

    public static APIService getAPIService() {
        return RetrofitClient.getClient(BASE_URL).create(APIService.class);
    }

}
public class RetrofitClient {
   private static Retrofit retrofit = null;

   private static Gson gson = new GsonBuilder()
        .setLenient()
        .create();

   public static Retrofit getClient(String baseUrl) {
      if (retrofit==null) {
        retrofit = new Retrofit.Builder()
                .baseUrl(baseUrl)
                .addConverterFactory(GsonConverterFactory.create(gson))
                .build();
      }
      return retrofit;
   }
}

Reason I posted all this was I couldn't find where the problem is because JSON response I'm getting from API looks ok, the way I called the API looks ok. There are many questions related to this can be found here. But I couldn't find the answer to my problem. Please find me a solution to this. Thanks

EDIT : @Darpan and @Fred was right. I enabled the logging for retrofit. this is what it says

D/OkHttp: --> POST http://myurl/posts http/1.1
D/OkHttp: Content-Type: application/x-www-form-urlencoded
D/OkHttp: Content-Length: 26
D/OkHttp: title=vz&body=gde&userId=1
D/OkHttp: --> END POST (26-byte body)
D/OkHttp: <-- 200 OK http://mywebsite/404/
    <html of my 404 page>
D/OkHttp: <-- END HTTP (2119-byte body)

It's giving me my servers' 404.html file as the response. but When I call the same API from POSTMAN it's giving me the desired result.

So basically I can access and get the result from POSTMAN but cannot consume it from Android app using retrofit

Any idea how to fix it? what can be the problem?

回答1:

Remove the last / from your base url http://myurl/v1/

That's why it is throwing 404.

回答2:

Create bellow class and change Call<Post> to Call<MyResponse>

public class MyResponse {

    @SerializedName("result")
    private String result;

    @SerializedName("data")
    private Data data;

    public class Data {

        @SerializedName("title")
        @Expose
        private String title;

        @SerializedName("body")
        @Expose
        private String body;

        @SerializedName("userId")
        @Expose
        private String userId;

        @SerializedName("id")
        @Expose
        private String id;

        public String getTitle() {
            return title;
        }

        public void setTitle(String title) {
            this.title = title;
        }

        public String getBody() {
            return body;
        }

        public void setBody(String body) {
            this.body = body;
        }

        public String getUserId() {
            return userId;
        }

        public void setUserId(String userId) {
            this.userId = userId;
        }

        public String getId() {
            return id;
        }

        public void setId(String id) {
            this.id = id;
        }
    }

    public String getResult() {
        return result;
    }

    public void setResult(String result) {
        this.result = result;
    }

    public Data getData() {
        return data;
    }

    public void setData(Data data) {
        this.data = data;
    }
}

Your should change your json format like this

{
    "result" : "success",
    "data" : {
            "title":"title",
            "body":"body",
            "user_id":"userid",
            "id":"id"
    }   
}

Now you can access it in response like this MyResponse res= response.body();

And also print response like this Log.d("response", new Gson().toJson(res));