Retrofit 2.0 - How to get response body for 400 Bad Request error?

Question

So when I make a POST API call to my server, I get a 400 Bad Request error with JSON response.

{
    \"userMessage\": \"Blah\",
    \"internalMessage\": \"Bad Re         


        

Answer 1

Here is the simplest solution,

If you want to handle the response from onFailure method:

@Override
public void onFailure(Call call, Throwable t) {
    HttpException httpException = (HttpException) t;
    String errorBody = httpException.response().errorBody().string();
    // use Gson to parse json to your Error handling model class
    ErrorResponse errorResponse = Gson().fromJson(errorBody, ErrorResponse.class);
}

Or if you are using rxjava Observable with Kotlin, handle it from error body:

{ error ->
    val httpException :HttpException = error as HttpException
    val errorBody: String = httpException.response().errorBody()!!.string()
    // use Gson to parse json to your Error handling model class
    val errorResponse: ErrorResponse = 
       Gson().fromJson(errorBody, ErrorResponse::class.java)
}

Don't forget to properly handle json to class conversion (use try-catch if not sure).