JSON Error “java.lang.IllegalStateException: Expected BEGIN_OBJECT but was STRING at line 1 column 1 path $”

public interface UserService {
    @POST(Constants.Api.URL_REGISTRATION)
    @FormUrlEncoded
    BaseWrapper registerUser(@Field("first_name") String firstname, @Field("last_name") String lastname, @Field("regNumber") String phone, @Field("regRole") int role);


 public BaseWrapper registerUser(User user) {
        return getUserService().registerUser(user.getFirstName(), user.getLastName(), user.getPhone(), user.getRole());
    }

This create Exception

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

Big thanks for help.

Answer

Let’s look at the error you are receiving.

Expected BEGIN_OBJECT

Your JSON is an object, and all JSON objects are enclosed in curly braces ({}). BEGIN_OBJECT is therefore {. And it’s expecting it somewhere.

but was STRING

But instead he found a string “Something”. Still doesn’t tell us where.

at line 1 column 1 path $

Ah, perfect. At line 1 column 1. Which is the start of the JSON. So you have forgotten to enclose the whole thing in {} (or at least you have forgotten the first one, but I bet you’ve forgotten them both).