WebClient - how to get request body?

Question

I've started using WebClient and I'm adding logging of request/response and I'm using filter method when constructing WebClient:

WebClient.builder()
    .baseUrl(properties.getEndpoint())
    .filter((request, next) -> {
        // logging
        request.body()
    })
    .build();

I'm able to access url, http method, headers but I've a problem with getting raw request body as body() method of request returns BodyInserter (BodyInserter<?, ? super ClientHttpRequest> body().

How to convert BodyInserter to String representation of request body? Alternatively, how to properly log whole request/response while also being able to hash potential credentials in it?

Answer 1

尝试了所有答案，但其中一些不符合我的需要或根本不起作用。根据这个答案编写了我自己的解决方案来拦截请求/响应主体并记录它们。

@Slf4j
@Component
public class LoggingCustomizer implements WebClientCustomizer {

    @Override public void customize(WebClient.Builder webClientBuilder) {
        webClientBuilder.filter((request, next) -> {
            logRequest(request);
            return next
                .exchange(interceptBody(request))
                .doOnNext(this::logResponse)
                .map(this::interceptBody);
        });
    }

    private ClientRequest interceptBody(ClientRequest request) {
        return ClientRequest.from(request)
            .body((outputMessage, context) -> request.body().insert(new ClientHttpRequestDecorator(outputMessage) {
                @Override public Mono<Void> writeWith(Publisher<? extends DataBuffer> body) {
                    return super.writeWith(Mono.from(body)
                        .doOnNext(dataBuffer -> logRequestBody(dataBuffer)));
                }
            }, context))
            .build();
    }

    private ClientResponse interceptBody(ClientResponse response) {
        return response.mutate()
            .body(data -> data.doOnNext(this::logResponseBody))
            .build();
    }

    private void logRequest(ClientRequest request) {
        log.debug("DOWNSTREAM REQUEST: METHOD {}, URI: {}, HEADERS: {}", request.method(), request.url(), request.headers());
    }

    private void logRequestBody(DataBuffer dataBuffer) {
        log.debug("DOWNSTREAM REQUEST: BODY: {}", dataBuffer.toString(StandardCharsets.UTF_8));
    }

    private void logResponse(ClientResponse response) {
        log.debug("DOWNSTREAM RESPONSE: STATUS: {}, HEADERS: {}", response.rawStatusCode(), response.headers().asHttpHeaders());
    }

    private void logResponseBody(DataBuffer dataBuffer) {
        log.debug("DOWNSTREAM RESPONSE: BODY: {}", dataBuffer.toString(StandardCharsets.UTF_8));
    }

}

更新：添加了使用日志片段reactor.netty.http.client.HttpClient（首选解决方案）

@Slf4j
@Component
public class LoggingCustomizer implements WebClientCustomizer {

    @Override public void customize(WebClient.Builder webClientBuilder) {
        HttpClient httpClient = HttpClient.create()
            .doOnRequest((httpClientRequest, connection) -> connection.addHandlerFirst(new LoggingHandler()));
        webClientBuilder.clientConnector(new ReactorClientHttpConnector(httpClient));
    }

    private static class LoggingHandler extends ChannelDuplexHandler {

        @Override public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
            if (msg instanceof FullHttpRequest request) {
                log.debug("DOWNSTREAM  REQUEST: METHOD: {}, URI: {}, BODY: {}, HEADERS: {}",
                    request.method(), request.uri(), request.content().toString(defaultCharset()), request.headers());
            } else if (msg instanceof HttpRequest request) {
                log.debug("DOWNSTREAM  REQUEST: METHOD: {}, URI: {}, HEADERS: {}",
                    request.method(), request.uri(), request.headers());
            } else if (msg instanceof FullHttpMessage message) {
                log.debug("DOWNSTREAM  REQUEST: BODY: {}",
                    message.content().toString(defaultCharset()));
            }
            super.write(ctx, msg, promise);
        }

        @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
            if (msg instanceof FullHttpResponse response) {
                log.debug("DOWNSTREAM RESPONSE: STATUS: {}, BODY: {}, HEADERS: {}",
                    response.status().code(), response.content().toString(defaultCharset()), response.headers());
            } else if (msg instanceof HttpResponse response) {
                log.debug("DOWNSTREAM RESPONSE: STATUS: {}, HEADERS: {}",
                    response.status().code(), response.headers());
            } else if (!(msg instanceof LastHttpContent) && msg instanceof HttpContent httpContent) {
                log.debug("DOWNSTREAM RESPONSE: BODY: {}",
                    httpContent.content().toString(defaultCharset()));
            }
            super.channelRead(ctx, msg);
        }
    }

}

Answer 2

回到主题并给出答案，到目前为止我很满意。

在下面的示例中，我HttpClient使用LoggingHandler创建了日志记录魔法，将其注入到ReactorClientHttpConnectordefault 中HttpConnector（请参阅DefaultWebClientBuilder#initConnector），然后注入到WebClient.

val baseHttpClient = HttpClient.create()
    .doOnRequest(
        (request, conn) -> conn.addHandlerFirst(new LoggingHandler(LogLevel.INFO)
    ));

val httpClient = WebClient.builder()
    .baseUrl("https://google.pl")
    .clientConnector(new ReactorClientHttpConnector(baseHttpClient))
    .build();

val response = httpClient.post()
    .body(Mono.just("Your request body"), String.class)
    .exchangeToMono(clientResponse -> clientResponse.bodyToMono(String.class))
    .block();

我仍然计划创建自定义LoggingHandler来清理和简化日志。