如何在spring启动应用程序中关闭客户端sse连接

Question

我有一个spring引导应用程序，我必须使用SSE连接到一些外部服务。WebClient建立连接，然后我使用Flux读取响应。一切工作正常，但问题是连接保持打开状态，因为该过程不是设计为每次在第三方服务中都到达终点。我想作为客户端手动关闭连接，因为我知道这个连接何时应该完成。我该怎么做呢?

建立连接:

private Flux<ServerSentEvent<String>> connect(String accessToken) {
TcpClient timeoutClient = createTimeoutClient();
ReactorClientHttpConnector reactorClientHttpConnector = new ReactorClientHttpConnector(HttpClient.from(timeoutClient));
String url = npzServerBaseUrl+uniqueCodePath;
WebClient client = WebClient
.builder()
.clientConnector(reactorClientHttpConnector)
.defaultHeader(HttpHeaders.AUTHORIZATION, Naming.TOKEN_PREFIX + accessToken)
.baseUrl(url)
.build();
ParameterizedTypeReference<ServerSentEvent<String>> type
= new ParameterizedTypeReference<ServerSentEvent<String>>() {};
return client.get()
.retrieve()
.onStatus(HttpStatus::is4xxClientError, clientResponse -> {
String msg = "Error from server: "+clientResponse.statusCode().toString();
//invalidate access token
if (clientResponse.statusCode().value()==401) {
//remove invalid token and connect again
loginContext.invalidToken(accessToken);
return Mono.error(new InvalidNpzToken(msg));
}
return Mono.error(new IllegalStateException(msg));
}
)
.onStatus(HttpStatus::is5xxServerError, clientResponse ->
Mono.error(new IllegalStateException("Error from server: "+clientResponse.statusCode().toString()))
)
.bodyToFlux(type);
}
private TcpClient createTimeoutClient() {
return TcpClient.create()
.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, SECONDS*1000)
.option(EpollChannelOption.TCP_USER_TIMEOUT, SECONDS*1000)
.doOnConnected(
c -> c.addHandlerLast(new ReadTimeoutHandler(SECONDS))
.addHandlerLast(new WriteTimeoutHandler(SECONDS)));
}

处理内容:

Flux<ServerSentEvent<String>> eventStream = connect(accessToken);
eventStream.subscribe(
content -> {
log.info("Time: {} - event: name[{}], id [{}], content[{}] ",
LocalTime.now(), content.event(), content.id(), content.data());
if ("uuid".equals(content.event().trim())) {
listener.receivedUniqueCode(content.data().trim());
} else if ("code".equals(content.event().trim())) {
listener.receivedCode(content.data().trim());
}
},
(Throwable error) -> {
if (error instanceof InvalidToken) {
log.error("Error receiving SSE", error);
//let's retry connection as token has expired
getCode(request, listener);
}
},
() -> log.info("Connection closed!"));

我所期望的是，我可以调用connection.close()或类似的东西，连接将被关闭。

感谢如果需要更多的信息

进口:

import io.netty.channel.ChannelOption;
import io.netty.channel.epoll.EpollChannelOption;
import io.netty.handler.timeout.ReadTimeoutHandler;
import io.netty.handler.timeout.WriteTimeoutHandler;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.ParameterizedTypeReference;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.reactive.ReactorClientHttpConnector;
import org.springframework.http.codec.ServerSentEvent;
import org.springframework.stereotype.Component;
import org.springframework.web.reactive.function.client.WebClient;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import reactor.netty.http.client.HttpClient;
import reactor.netty.tcp.TcpClient;

春季启动:

<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.1.RELEASE</version>

Answer 1

eventStream.subscribe()返回reactor.core.Disposable

您可以调用dispose()来取消订阅和底层资源。