Java Spring Webflux，记录出站http调用所用的时间

Question

 @Override
    public Mono<String> sendOutboundRequest() {
        return webClient.post().retrieve().bodyToMono(String.class);
    }

 long start = System.nanoTime();
        Mono<String> result = webClientIdms.post().retrieve().bodyToMono(String.class);
        long end = System.nanoTime() - start;
        LOGGER.info("this will not print the actual http request time " + end);
        return result;

Answer 1

如果您希望以一种可重用的方式完成此操作，可以使用ExchangeFilterFunction。您可以在spring参考文档中找到ExchangeFilterFunction的更多示例

下面是ExchangeFilterFunction的示例实现，它将对WebClient进行的每个外部api调用计时并记录结果。这从MetricsWebClientFilterFunction获得灵感

@Component
public class MetricsLoggingExchangeFilterFunction implements ExchangeFilterFunction {

    private static final Logger LOGGER = LoggerFactory.getLogger(MetricsLoggingExchangeFilterFunction.class);
    private static final String METRICS_WEBCLIENT_START_TIME = MetricsLoggingExchangeFilterFunction.class.getName() + ".START_TIME";

    @Override
    public Mono<ClientResponse> filter(ClientRequest request, ExchangeFunction next) {
        return next.exchange(request).doOnEach((signal) -> {
            if (!signal.isOnComplete()) {
                Long startTime = signal.getContextView().get(METRICS_WEBCLIENT_START_TIME);
                long duration = System.currentTimeMillis() - startTime;
                LOGGER.info("Downstream called taken {}ms", duration);
            }
        }).contextWrite(ctx -> ctx.put(METRICS_WEBCLIENT_START_TIME, System.currentTimeMillis()));
    }
}

然后，可以使用提供的webclient.builderIE将其添加到任何WebClient实例中，以便记录持续时间。

WebClient.builder().filter(metricsLoggingExchangeFilterFunction).build()