[Java][WebClient] Possibility to override the invokeAPI method

Description

In some cases, it would be very useful to be able to extend the ApiClient behaviour in a WebClient.

Currently, the code looks like this:

ApiClient.java

    public <T> Mono<T> invokeAPI(String path, HttpMethod method, Map<String, Object> pathParams, MultiValueMap<String, String> queryParams, Object body, HttpHeaders headerParams, MultiValueMap<String, String> cookieParams, MultiValueMap<String, Object> formParams, List<MediaType> accept, MediaType contentType, String[] authNames, ParameterizedTypeReference<T> returnType) throws RestClientException {
        final WebClient.RequestBodySpec requestBuilder = prepareRequest(path, method, pathParams, queryParams, body, headerParams, cookieParams, formParams, accept, contentType, authNames);
        return requestBuilder.retrieve().bodyToMono(returnType);
    }

 private WebClient.RequestBodySpec prepareRequest(String path, HttpMethod method, Map<String, Object> pathParams, MultiValueMap<String, String> queryParams, Object body, HttpHeaders headerParams, MultiValueMap<String, String> cookieParams, MultiValueMap<String, Object> formParams, List<MediaType> accept, MediaType contentType, String[] authNames) {
...
}

Solution

To do so, I propose to define as protected the prepareRequest method inside ApiClient.java. This way, you could override the invokeAPI method and use the prepareRequest method.

Change:

 protected WebClient.RequestBodySpec prepareRequest(String path, HttpMethod method, Map<String, Object> pathParams, MultiValueMap<String, String> queryParams, Object body, HttpHeaders headerParams, MultiValueMap<String, String> cookieParams, MultiValueMap<String, Object> formParams, List<MediaType> accept, MediaType contentType, String[] authNames) {
...
}

I could make the contribution myself.

How do you see it?

Start in ApiClient.java by reading invokeAPI and the private prepareRequest method. Check how the WebClient request is assembled, then expose prepareRequest for subclass use while preserving the existing invocation behavior. Done means a custom ApiClient can override invokeAPI and call prepareRequest.