How to avoid Method Overloading in Java to avoid duplicates?

Question

I have 2 method which performs 80% same work but differ in result processing. I am doing :

 private <T> T getResponse(final RestURI query, final Class<T> responseClass) throws IOException {
        T response = null;

        final RestResponse<Record> tempResponse = getResponseFromDataPath(query);

        if (isResponseOK(tempResponse, query)) {
            final CustomReader reader = createCustomReaderFromResponse(tempResponse);
            response = objectMapper.readValue(reader, responseClass);
                                                          ^
            // DIFFERENCE --------------------------------|
        }

        return response;
    }

    private <T> T getResponse(final RestURI query, final TypeReference valueTypeRef) throws IOException {
        T response = null;

        final RestResponse<Record> tempResponse = getResponseFromDataPath(query);

        if (isResponseOK(tempResponse, query)) {
            final CustomReader reader = createCustomReaderFromResponse(tempResponse);
            response = objectMapper.readValue(reader, valueTypeRef);
                                                          ^
            // DIFFERENCE --------------------------------|
        }

        return response;
    }

This looks like lot of duplicate. How do I make this such that I reduce the duplicates.

Answer 1

You can use a BiFunction parameter that calls objectMapper :

private <T> T getResponse(final RestURI query, 
    final BiFunction<CustomReader, ObjectMapper, T> mapper) throws IOException {
    T response = null;

    final RestResponse<Record> tempResponse = getResponseFromDataPath(query);

    if (isResponseOK(tempResponse, query)) {
        final CustomReader reader = createCustomReaderFromResponse(tempResponse);
        response = mapper.apply(reader, objectMapper); 
    }

    return response;
}

And callers can choose how to call objectMapper :

getResponse(query, 
   (reader, objectMapper) -> objectMapper.readValue(reader, <valueTypeRef>);

Or:

getResponse(query, 
    (reader, objectMapper) -> objectMapper.readValue(reader, <class>);