protected abstract ProgressEvent handleRequest()

in aws-rds-dbclusterparametergroup/src/main/java/software/amazon/rds/dbclusterparametergroup/BaseHandlerStd.java [44:88]
30 lines of code
6 McCabe index (conditional complexity)

    protected abstract ProgressEvent<ResourceModel, CallbackContext> handleRequest(AmazonWebServicesClientProxy proxy,
                                                                                   ResourceHandlerRequest<ResourceModel> request,
                                                                                   CallbackContext callbackContext,
                                                                                   ProxyClient<RdsClient> client,
                                                                                   Logger logger);

    protected ProgressEvent<ResourceModel, CallbackContext> applyParameters(final AmazonWebServicesClientProxy proxy,
                                                                            final ProxyClient<RdsClient> proxyClient,
                                                                            final ResourceModel model,
                                                                            final CallbackContext callbackContext) {
        if (callbackContext.isParametersApplied()) return ProgressEvent.defaultInProgressHandler(callbackContext, NO_CALLBACK_DELAY, model);

        callbackContext.setParametersApplied(true);
        ProgressEvent<ResourceModel, CallbackContext> progress = ProgressEvent.defaultInProgressHandler(callbackContext, CALLBACK_DELAY_SECONDS, model);

        if (model.getParameters().isEmpty()) return progress;

        // check if provided parameter is supported by rds
        Set<String> paramNames = model.getParameters().keySet();

        String marker = null;
        do {

            final DescribeDbClusterParametersResponse dbClusterParametersResponse = proxyClient.injectCredentialsAndInvokeV2(
                    Translator.describeDbClusterParametersRequest(model, marker), proxyClient.client()::describeDBClusterParameters);

            marker = dbClusterParametersResponse.marker();
            final Set<Parameter> params = Translator.getParametersToModify(model, dbClusterParametersResponse.parameters());

            // if no params need to be modified then skip the api invocation
            if (params.isEmpty()) continue;

            // substract set of found and modified params
            paramNames.removeAll(params.stream().map(Parameter::parameterName).collect(Collectors.toSet()));

            progress = proxy.initiate("rds::modify-db-cluster-parameter-group::" + marker, proxyClient, model, callbackContext)
                    .translateToServiceRequest((resourceModel) -> Translator.modifyDbClusterParameterGroupRequest(resourceModel, params))
                    .makeServiceCall((request, proxyInvocation) -> proxyInvocation.injectCredentialsAndInvokeV2(request, proxyInvocation.client()::modifyDBClusterParameterGroup))
                    .progress(CALLBACK_DELAY_SECONDS);
        } while (!StringUtils.isNullOrEmpty(marker));
        // if there are parameters left that couldn't be found in rds api then they are invalid
        if (!paramNames.isEmpty()) throw new CfnInvalidRequestException("Invalid / Unsupported DB Parameter: " + paramNames.stream().findFirst().get());

        return progress;
    }