Converter Factory for Retrofit 2.0

RawStringConverter.java

public class RawStringConverter extends Converter.Factory {

  @Override
  public Converter<ResponseBody, ?> fromResponseBody(Type type, Annotation[] annotations) {
    //noinspection EqualsBetweenInconvertibleTypes
    if (String.class.equals(type)) {
      return ResponseBody::string;
    }

    return null;
  }

  @Override public Converter<?, RequestBody> toRequestBody(Type type, Annotation[] annotations) {
    //noinspection EqualsBetweenInconvertibleTypes
    if (String.class.equals(type)) {
      try {
        return (String value) -> RequestBody.create(MediaType.parse("text/plain"), value);
      } catch (Exception e) {
        e.printStackTrace();
      }
    }

    return null;
  }
}

https://github.com/square/retrofit/blob/07d1f3de5e0eb11fb537464bd14fdbacfc9e55a7/retrofit/src/test/java/retrofit/ToStringConverterFactory.java