如何解决此错误 Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 1 column 2 path $

Question

I am working on a project with a django restframework backend,I have done the backend and tested it's working properly but now I want to connect my android application to the APIs but it is at this point that I want to fetch this resposnse after a successfully registration and get some data to use in the next activity that I'm getting an error although data is saved in the database

Here is my APIClient Interface class

package com.example.covid_19_tracker.data.network;
import com.example.covid_19_tracker.data.network.model.AddLocationResponse;
import com.example.covid_19_tracker.data.network.model.LoginResponse;
import com.example.covid_19_tracker.data.network.model.RegisterDeviceResponse;
import com.example.covid_19_tracker.data.network.model.RegisterUserResponse;

import java.util.HashMap;

import io.reactivex.Observable;
import retrofit2.http.FieldMap;
import retrofit2.http.FormUrlEncoded;
import retrofit2.http.POST;

public interface ApiInterface {

    @FormUrlEncoded
    @POST("api/locations/")
    Observable<AddLocationResponse> addLocation(@FieldMap HashMap<String, Object> params);

    @FormUrlEncoded
    @POST("api/devices/")
    Observable<RegisterDeviceResponse> registerDevice(@FieldMap HashMap<String, Object>   params);

    @FormUrlEncoded
    @POST("api/accounts/register/")
    Observable<RegisterUserResponse> registerUser(@FieldMap HashMap<String, Object> params);

    @FormUrlEncoded
    @POST("api/accounts/login/")
    Observable<LoginResponse> loginUser(@FieldMap HashMap<String, Object> params);
}

And here is my RegisterUserResponse.java model Class

package com.example.covid_19_tracker.data.network.model;

import com.google.gson.annotations.Expose;
import com.google.gson.annotations.SerializedName;

import java.util.ArrayList;

public class RegisterUserResponse {
    @SerializedName("success")
    @Expose
    private String success;
    @SerializedName("status_code")
    @Expose
    private Integer status_code;
    @SerializedName("message")
    @Expose
    private String message;
    @SerializedName("data")
    @Expose
    private ArrayList data = new ArrayList();
    @SerializedName("token")
    @Expose
    private String token;

    public RegisterUserResponse() {
    }

    public String getSuccess() {
        return success;
    }

    public void setSuccess(String success) {
        this.success = success;
    }

    public Integer getStatus_code() {
        return status_code;
    }

    public void setStatus_code(Integer status_code) {
        this.status_code = status_code;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public ArrayList getData() {
        return data;
    }

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

    public String getToken() {
        return token;
    }

    public void setToken(String token) {
        this.token = token;
    }
}

But I'm getting the error Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 1 column 2 path $ I'm a beginner in android. Thank you

Answer 1

Your data field is not an ArrayList as you specified in your RegisterUserResponse class

You need to create a Data class that will contains the fields id username password ...

and then in your RegisterUserResponse class you will declare:

@SerializedName("data")
    @Expose
    private Data data;

instead of:

@SerializedName("data")
    @Expose
    private ArrayList data = new ArrayList();