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

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 Request blah blah",
    "errorCode": 1
}

I call it by

Call.enqueue(new Callback<ResponseBody>() {
    @Override
    public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
        //AA
    }

    @Override
    public void onFailure(Call<ResponseBody> call, Throwable t) {
        //BB
    }
}

However the problem is that once I get the response, onFailure() is invoke so that //BB is called. Here, I have no way to access the JSON response. When I log the api request and response, it doesn't show JSON response at all. And Throwable t is IOException. However, strangely, when I make the same call on Postman, it does return the expected JSON response with 400 error code.

So my question is how can I get the json response when I get 400 Bad Request error? Should I add something to okhttpclient?

Thanks

Solution 1:

You can do it in your onResponse method, remember 400 is a response status not an error:

if (response.code() == 400) {              
    Log.v("Error code 400",response.errorBody().string());
}

And you can handle any response code except 200-300 with Gson like that:

if (response.code() == 400) {
   Gson gson = new GsonBuilder().create();
   ErrorPojoClass mError=new ErrorPojoClass();
   try {
       mError= gson.fromJson(response.errorBody().string(),ErrorPojoClass.class);
       Toast.makeText(context, mError.getDescription(), Toast.LENGTH_LONG).show();
   } catch (IOException e) {
       // handle failure to read error
   }        
}

Add this to your build.gradle : compile 'com.google.code.gson:gson:2.7'

If you want create Pojo class go to Json Schema 2 Pojo and paste your example Json response. Select source type Json and annotation Gson .

Solution 2:

You can try the below code to get 400 response. You can get error response from errorBody() method.

Call.enqueue(new Callback<ResponseBody>() {
    @Override
    public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
        //get success and error response here
 if (response.code() == 400) {
                if(!response.isSuccessful()) {
                    JSONObject jsonObject = null;
                    try {
                        jsonObject = new JSONObject(response.errorBody().string());
                        String userMessage = jsonObject.getString("userMessage");
                        String internalMessage = jsonObject.getString("internalMessage");
                        String errorCode = jsonObject.getString("errorCode");
                    } catch (JSONException e) {
                        e.printStackTrace();
                    }
                }
            }

    @Override
    public void onFailure(Call<ResponseBody> call, Throwable t) {
        //get failure response here
    }
}
}

EDIT: Fixed method name from toString to string

Solution 3:

public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
    DialogHelper.dismiss();

    if (response.isSuccessful()) {
        // Success
    } else {
        try {
            JSONObject jObjError = new JSONObject(response.errorBody().string());
            Toast.makeText(getContext(), jObjError.getString("message"), Toast.LENGTH_LONG).show();
        } catch (Exception e) {
            Toast.makeText(getContext(), e.getMessage(), Toast.LENGTH_LONG).show();
        }
    }
}

Solution 4:

First step:

Create your POJO class for error response. In my case, ApiError.java

public class ApiError {

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

    public String getErrorMessage() {
        return errorMessage;
    }

    public void setErrorMessage(String errorMessage) {
        this.errorMessage= errorMessage;
    }
}

Second Step:

Write below code in your api callback.

Call.enqueue(new Callback<RegistrationResponse>() {
     @Override
     public void onResponse(Call<RegistrationResponse> call, Response<RegistrationResponse> response) 
     {
         if (response.isSuccessful()) {
             // do your code here
         } else if (response.code() == 400) {
             Converter<ResponseBody, ApiError> converter =
                            ApiClient.retrofit.responseBodyConverter(ApiError.class, new Annotation[0]);

                    ApiError error;

                    try {
                        error = converter.convert(response.errorBody());
                        Log.e("error message", error.getErrorMessage());
                        Toast.makeText(context, error.getErrorMessage(), Toast.LENGTH_LONG).show();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
         }
     }

     @Override
     public void onFailure(Call<RegistrationResponse> call, Throwable t) {
         //do your failure handling code here
     }
}

Here ApiClient.retrofit is your retrofit instance which is static.