PrematureCloseException：连接过早关闭

Question

我使用 Web-flux/Reactive 和 Webclient，在 tomcat 和 spring-boot 上运行它。

一切正常。我阅读了很多关于它的信息。问题似乎是每当你使用 webclient 时，你必须返回或使用响应，否则它会关闭连接而你还没有使用它，你会看到很多日志消息说the connection close prematurely，如果我有404 状态代码是一个错误的场景，我可以使用OnStatus并抛出异常，但我的情况是：当上游服务返回 404 时，我必须手动返回单声道空。所以我不使用来自 Web 客户端请求的响应，我只是使用来自 .exchange() 的 ClientResponse 来检查状态并处理它。我最初的问题是日志消息，因为这只是“垃圾”，您不希望在日志消息中看到很多。我在某处读到，如果发生这种情况，连接也不能重复使用，所以这听起来很糟糕，但我不知道......如果没有找到，我只会收到这条消息，如果响应是 200它返回对象并且不打印日志消息。

我尝试使用 clientResponse.BodyToMono(Void.Class) 但它也不起作用。保持出现的日志消息

 @Bean
  public WebClient webClient(
      @Value("${http.client.connection-timeout-millis}") final int connectionTimeoutMillis,
      @Value("${http.client.socket-timeout-millis}") final int socketTimeoutMillis,
      @Value("${http.client.wire-tap-enabled}") final boolean wireTapEnabled,
      final ObjectMapper objectMapper) {

    Consumer<Connection> doOnConnectedConsumer = connection ->
        connection
            .addHandler(new ReadTimeoutHandler(socketTimeoutMillis, MILLISECONDS))
            .addHandler(new WriteTimeoutHandler(connectionTimeoutMillis, MILLISECONDS));

    TcpClient tcpClient = TcpClient.newConnection()
        .wiretap(wireTapEnabled)
        .option(CONNECT_TIMEOUT_MILLIS, connectionTimeoutMillis)
        .doOnConnected(doOnConnectedConsumer);

    return WebClient.builder()
        .clientConnector(new ReactorClientHttpConnector(HttpClient.from(tcpClient).compress(true)))
        .exchangeStrategies(customExchangeStrategies(objectMapper))
        .build();
  } 

// ..........

    MultiValueMap<String, String> params = getParams(t1, t2);

    return webClient.get()
        .uri(HttpUtils.buildUrl(serviceUrl, params, name))
        .exchange()
        .flatMap(this::handleClientResponse)
        .onErrorMap(Exception.class, ex -> handleUnexpectedEx(ex, name, params));
  }

日志条目

2019-07-08 11:56:51.972  WARN [-,,,] 1504 --- [ctor-http-nio-3] reactor.netty.channel.FluxReceive        : [id: 0x66c8568c, L:/127.0.0.1:62319 ! R:localhost/127.0.0.1:8990] An exception has been observed post termination

reactor.netty.http.client.PrematureCloseException: Connection prematurely closed DURING response

2019-07-08 11:56:52.013 DEBUG [-,,,] 1504 --- [ctor-http-nio-2] reactor.netty.ReactorNetty               : [id: 0xf50bdf8d, L:/127.0.0.1:62324 ! R:localhost/127.0.0.1:8990] Non Removed handler: ReadTimeoutHandler, context: ChannelHandlerContext(ReadTimeoutHandler, [id: 0xf50bdf8d, L:/127.0.0.1:62324 ! R:localhost/127.0.0.1:8990]), pipeline: DefaultChannelPipeline{(reactor.left.httpCodec = io.netty.handler.codec.http.HttpClientCodec), (reactor.left.decompressor = io.netty.handler.codec.http.HttpContentDecompressor), (WriteTimeoutHandler = io.netty.handler.timeout.WriteTimeoutHandler), (ReadTimeoutHandler = io.netty.handler.timeout.ReadTimeoutHandler), (reactor.right.reactiveBridge = reactor.netty.channel.ChannelOperationsHandler)}
2019-07-08 11:56:52.014 DEBUG [-,,,] 1504 --- [ctor-http-nio-2] reactor.netty.ReactorNetty               : [id: 0xf50bdf8d, L:/127.0.0.1:62324 ! R:localhost/127.0.0.1:8990] Non Removed handler: WriteTimeoutHandler, context: ChannelHandlerContext(WriteTimeoutHandler, [id: 0xf50bdf8d, L:/127.0.0.1:62324 ! R:localhost/127.0.0.1:8990]), pipeline: DefaultChannelPipeline{(reactor.left.httpCodec = io.netty.handler.codec.http.HttpClientCodec), (reactor.left.decompressor = io.netty.handler.codec.http.HttpContentDecompressor), (WriteTimeoutHandler = io.netty.handler.timeout.WriteTimeoutHandler), (ReadTimeoutHandler = io.netty.handler.timeout.ReadTimeoutHandler), (reactor.right.reactiveBridge = reactor.netty.channel.ChannelOperationsHandler)}
2019-07-08 11:56:52.014 DEBUG [-,,,] 1504 --- [ctor-http-nio-2] r.netty.resources.NewConnectionProvider  : [id: 0xf50bdf8d, L:/127.0.0.1:62324 ! R:localhost/127.0.0.1:8990] onStateChange([response_incomplete], GET{uri=/service/TWFDHF?T1=1.0.0&T2=1, connection=SimpleConnection{channel=[id: 0xf50bdf8d, L:/127.0.0.1:62324 ! R:localhost/127.0.0.1:8990]}})
2019-07-08 11:56:52.014  WARN [-,,,] 1504 --- [ctor-http-nio-2] reactor.netty.channel.FluxReceive        : [id: 0xf50bdf8d, L:/127.0.0.1:62324 ! R:localhost/127.0.0.1:8990] An exception has been observed post termination

启用窃听的日志条目

2019-07-10 14:51:19.295 DEBUG [-,,,] 2940 --- [ctor-http-nio-2] reactor.netty.tcp.TcpClient              : [id: 0x677da0d4, L:/127.0.0.1:62385 ! R:localhost/127.0.0.1:8990] UNREGISTERED
2019-07-10 14:51:19.541 DEBUG [-,,,] 2940 --- [ctor-http-nio-4] reactor.netty.tcp.TcpClient              : [id: 0xa7f41d1e, L:/127.0.0.1:62384 - R:localhost/127.0.0.1:8990] CLOSE
2019-07-10 14:51:19.542 DEBUG [-,,,] 2940 --- [ctor-http-nio-4] r.n.resources.PooledConnectionProvider   : [id: 0xa7f41d1e, L:/127.0.0.1:62384 ! R:localhost/127.0.0.1:8990] Channel cleaned, now 0 active connections and 9 inactive connections
2019-07-10 14:51:19.542 DEBUG [-,,,] 2940 --- [ctor-http-nio-4] r.n.resources.PooledConnectionProvider   : [id: 0xa7f41d1e, L:/127.0.0.1:62384 ! R:localhost/127.0.0.1:8990] Channel closed, now 0 active connections and 8 inactive connections
2019-07-10 14:51:19.542 DEBUG [-,,,] 2940 --- [ctor-http-nio-4] reactor.netty.ReactorNetty               : [id: 0xa7f41d1e, L:/127.0.0.1:62384 ! R:localhost/127.0.0.1:8990] Non Removed handler: ReadTimeoutHandler, context: ChannelHandlerContext(ReadTimeoutHandler, [id: 0xa7f41d1e, L:/127.0.0.1:62384 ! R:localhost/127.0.0.1:8990]), pipeline: DefaultChannelPipeline{(reactor.left.loggingHandler = io.netty.handler.logging.LoggingHandler), (reactor.left.httpCodec = io.netty.handler.codec.http.HttpClientCodec), (WriteTimeoutHandler = io.netty.handler.timeout.WriteTimeoutHandler), (ReadTimeoutHandler = io.netty.handler.timeout.ReadTimeoutHandler), (reactor.right.reactiveBridge = reactor.netty.channel.ChannelOperationsHandler)}
2019-07-10 14:51:19.543 DEBUG [-,,,] 2940 --- [ctor-http-nio-4] reactor.netty.ReactorNetty               : [id: 0xa7f41d1e, L:/127.0.0.1:62384 ! R:localhost/127.0.0.1:8990] Non Removed handler: WriteTimeoutHandler, context: ChannelHandlerContext(WriteTimeoutHandler, [id: 0xa7f41d1e, L:/127.0.0.1:62384 ! R:localhost/127.0.0.1:8990]), pipeline: DefaultChannelPipeline{(reactor.left.loggingHandler = io.netty.handler.logging.LoggingHandler), (reactor.left.httpCodec = io.netty.handler.codec.http.HttpClientCodec), (WriteTimeoutHandler = io.netty.handler.timeout.WriteTimeoutHandler), (ReadTimeoutHandler = io.netty.handler.timeout.ReadTimeoutHandler), (reactor.right.reactiveBridge = reactor.netty.channel.ChannelOperationsHandler)}
2019-07-10 14:51:19.543 DEBUG [-,,,] 2940 --- [ctor-http-nio-4] reactor.netty.tcp.TcpClient              : [id: 0xa7f41d1e, L:/127.0.0.1:62384 ! R:localhost/127.0.0.1:8990] INACTIVE
2019-07-10 14:51:19.544 DEBUG [-,,,] 2940 --- [ctor-http-nio-4] r.n.resources.PooledConnectionProvider   : [id: 0xa7f41d1e, L:/127.0.0.1:62384 ! R:localhost/127.0.0.1:8990] onStateChange(GET{uri=/dataviews/TWN_EMPLBENINFO_FIXED?version=1.0.0&sequence=1, connection=PooledConnection{channel=[id: 0xa7f41d1e, L:/127.0.0.1:62384 ! R:localhost/127.0.0.1:8990]}}, [response_incomplete])
2019-07-10 14:51:19.544  WARN [-,,,] 2940 --- [ctor-http-nio-4] reactor.netty.channel.FluxReceive        : [id: 0xa7f41d1e, L:/127.0.0.1:62384 ! R:localhost/127.0.0.1:8990] An exception has been observed post termination

和我的处理程序

protected Mono handleClientResponseError(final ClientResponse clientResponse) {
    clientResponse.bodyToMono(Void.class);
    Mono<ErrorResponse> errorResponse = clientResponse.body(BodyExtractors.toMono(ErrorResponse.class));

    return errorResponse.flatMap(err -> {
      log.debug("Received HttpStatusCodeException when calling {} Registry: {}", getGatewayName(),
          err.getErrorEnvelope().getMessage());

      return Mono.error(new UpStreamServiceHttpException(err, clientResponse.rawStatusCode()));
    }).switchIfEmpty(Mono.error(() -> {
      log.debug("Received HttpStatusCodeException when calling {} Registry: {}", getGatewayName());

      return new UpStreamServiceHttpException("Bad Gateway", clientResponse.rawStatusCode());
    }));
  }

我已经尝试使用clientResponse.bodyToMono(Void.class);来完成响应，但它仍然不起作用，我需要一种方法来完成来自网络客户端的响应，然后能够重新使用连接池并摆脱那些日志消息

我在 github 上创建了一个问题，但它已关闭，所以我在这里创建了这个问题。https://github.com/spring-projects/spring-framework/issues/23249

Answer 1

所以我终于找到了完成回复的方法，我将在这里与遇到此问题的任何人分享

在我有这个之前：

 private Mono<Optional<JsonNode>> handleHttpErrorStatus(final ClientResponse clientResponse) {
    if (clientResponse.statusCode().equals(HttpStatus.NOT_FOUND)) {
      clientResponse.bodyToMono(Void.class);
      return Mono.just(Optional.empty());
    } else {
      return handleClientResponseError(clientResponse);
    }
  }

但它没有用，显然是因为我无论如何都没有归还它，所以在挖掘之后我尝试了这个：

private Mono<Optional<JsonNode>> handleHttpErrorStatus(final ClientResponse clientResponse) {
    if (clientResponse.statusCode().equals(HttpStatus.NOT_FOUND)) {
      return clientResponse.bodyToMono(Void.class).thenReturn((Optional.empty()));
    } else {
      return handleClientResponseError(clientResponse);
    }
  }

它工作正常，我检查了窃听日志，现在一切看起来都很好。

2019-07-10 16:44:39.096 DEBUG [-,,,] 16260 --- [ctor-http-nio-2] r.n.http.client.HttpClientOperations     : [id: 0x461d8170, L:/127.0.0.1:64298 - R:localhost/127.0.0.1:8990] Received response (auto-read:false) : [Content-Type=application/json;charset=UTF-8, Transfer-Encoding=chunked, Date=Wed, 10 Jul 2019 15:44:38 GMT]
2019-07-10 16:44:39.096 DEBUG [-,,,] 16260 --- [ctor-http-nio-2] r.n.resources.PooledConnectionProvider   : [id: 0x461d8170, L:/127.0.0.1:64298 - R:localhost/127.0.0.1:8990] onStateChange(GET{uri=/dataviews/TWN_EMPLPIM_AVRO?version=1.0.0&sequence=1, connection=PooledConnection{channel=[id: 0x461d8170, L:/127.0.0.1:64298 - R:localhost/127.0.0.1:8990]}}, [response_received])
2019-07-10 16:44:39.098 DEBUG [-,bdd6433efa276f10,bdd6433efa276f10,false] 16260 --- [ctor-http-nio-2] reactor.netty.channel.FluxReceive        : [id: 0x461d8170, L:/127.0.0.1:64298 - R:localhost/127.0.0.1:8990] Subscribing inbound receiver [pending: 0, cancelled:false, inboundDone: false]
2019-07-10 16:44:39.099 DEBUG [-,bdd6433efa276f10,bdd6433efa276f10,false] 16260 --- [ctor-http-nio-2] reactor.netty.tcp.TcpClient              : [id: 0x461d8170, L:/127.0.0.1:64298 - R:localhost/127.0.0.1:8990] CLOSE
2019-07-10 16:44:39.099 DEBUG [-,bdd6433efa276f10,bdd6433efa276f10,false] 16260 --- [ctor-http-nio-2] r.n.resources.PooledConnectionProvider   : [id: 0x461d8170, L:/127.0.0.1:64298 ! R:localhost/127.0.0.1:8990] Channel cleaned, now 1 active connections and 1 inactive connections
2019-07-10 16:44:39.099 DEBUG [-,bdd6433efa276f10,bdd6433efa276f10,false] 16260 --- [ctor-http-nio-2] r.n.resources.PooledConnectionProvider   : [id: 0x461d8170, L:/127.0.0.1:64298 ! R:localhost/127.0.0.1:8990] Channel closed, now 1 active connections and 0 inactive connections
2019-07-10 16:44:39.099 DEBUG [-,bdd6433efa276f10,bdd6433efa276f10,false] 16260 --- [ctor-http-nio-2] reactor.netty.ReactorNetty               : [id: 0x461d8170, L:/127.0.0.1:64298 ! R:localhost/127.0.0.1:8990] Non Removed handler: ReadTimeoutHandler, context: ChannelHandlerContext(ReadTimeoutHandler, [id: 0x461d8170, L:/127.0.0.1:64298 ! R:localhost/127.0.0.1:8990]), pipeline: DefaultChannelPipeline{(reactor.left.loggingHandler = io.netty.handler.logging.LoggingHandler), (reactor.left.httpCodec = io.netty.handler.codec.http.HttpClientCodec), (WriteTimeoutHandler = io.netty.handler.timeout.WriteTimeoutHandler), (ReadTimeoutHandler = io.netty.handler.timeout.ReadTimeoutHandler), (reactor.right.reactiveBridge = reactor.netty.channel.ChannelOperationsHandler)}
2019-07-10 16:44:39.099 DEBUG [-,bdd6433efa276f10,bdd6433efa276f10,false] 16260 --- [ctor-http-nio-2] reactor.netty.ReactorNetty               : [id: 0x461d8170, L:/127.0.0.1:64298 ! R:localhost/127.0.0.1:8990] Non Removed handler: WriteTimeoutHandler, context: ChannelHandlerContext(WriteTimeoutHandler, [id: 0x461d8170, L:/127.0.0.1:64298 ! R:localhost/127.0.0.1:8990]), pipeline: DefaultChannelPipeline{(reactor.left.loggingHandler = io.netty.handler.logging.LoggingHandler), (reactor.left.httpCodec = io.netty.handler.codec.http.HttpClientCodec), (WriteTimeoutHandler = io.netty.handler.timeout.WriteTimeoutHandler), (ReadTimeoutHandler = io.netty.handler.timeout.ReadTimeoutHandler), (reactor.right.reactiveBridge = reactor.netty.channel.ChannelOperationsHandler)}
2019-07-10 16:44:39.100 DEBUG [-,,,] 16260 --- [ctor-http-nio-2] reactor.netty.tcp.TcpClient              : [id: 0x461d8170, L:/127.0.0.1:64298 ! R:localhost/127.0.0.1:8990] READ COMPLETE
2019-07-10 16:44:39.102 DEBUG [-,,,] 16260 --- [ctor-http-nio-2] reactor.netty.tcp.TcpClient              : [id: 0x461d8170, L:/127.0.0.1:64298 ! R:localhost/127.0.0.1:8990] INACTIVE
2019-07-10 16:44:39.102 DEBUG [-,,,] 16260 --- [ctor-http-nio-2] reactor.netty.tcp.TcpClient              : [id: 0x461d8170, L:/127.0.0.1:64298 ! R:localhost/127.0.0.1:8990] UNREGISTERED
2019-07-10 16:44:39.122 DEBUG [-,,,] 16260 --- [ctor-http-nio-2] reactor.netty.tcp.TcpClient              : [id: 0xbe2cb147, L:/127.0.0.1:64295 - R:localhost/127.0.0.1:8990] READ: 398B