spring boot 2 执行器端点不支持服务器发送事件 (SSE)

Question

我正在尝试使用 SSE 将一些指标公开为流。我能够使用来自 restController 的 SSE 事件，但是当我添加自定义执行器端点时，它只是以正确的方式关闭连接。

@Component
@Endpoint(id = "test")
public class StreamMetrics {

  
    @ReadOperation
    public Flux<ServerSentEvent<String>> streamEvents() {
        return Flux.interval(Duration.ofSeconds(1))
                .map(sequence -> ServerSentEvent.<String> builder()
                        .id(String.valueOf(sequence))
                        .event("pingpong")
                        .data("ping")
                        .build());
    }

}

结果

curl  -n -v http://localhost:9080/actuator/test
*   Trying ::1:9080...
* TCP_NODELAY set
* Connected to localhost (::1) port 9080 (#0)
> GET /actuator/test HTTP/1.1
> Host: localhost:9080
> User-Agent: curl/7.68.0
> Accept: */*
> 
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< transfer-encoding: chunked
< Content-Type: text/event-stream;charset=UTF-8
< 
id:0
event:pingpong
data:ping

* Connection #0 to host localhost left intact

这在第一个事件后立即终止

其中

@RestController
 @RequestMapping(value = "/test")
 public class SSETest {


    @GetMapping("/stream-sse")
    public Flux<ServerSentEvent<String>> streamEvents() {
        return Flux.interval(Duration.ofSeconds(1))
                .map(sequence -> ServerSentEvent.<String> builder()
                        .id(String.valueOf(sequence))
                        .event("pingpong")
                        .data("ping")
                        .build());
    }

}

结果

curl -v -n http://localhost:9080/test/stream-sse
*   Trying ::1:9080...
* TCP_NODELAY set
* Connected to localhost (::1) port 9080 (#0)
> GET /test/stream-sse HTTP/1.1
> Host: localhost:9080
> User-Agent: curl/7.68.0
> Accept: */*
> 
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< transfer-encoding: chunked
< Content-Type: text/event-stream;charset=UTF-8
< 
id:0
event:pingpong
data:ping

id:1
event:pingpong
data:ping

id:2
event:pingpong
data:ping

这会继续下去而不会被终止。

终止事件（连续流）的端点注释有什么特别之处？

我在“2.2.4”和“2.3.0”中对此进行了测试

Answer 1

我找到了答案。 @ReadOperation(produces = "text/event-stream") 将更改执行器端点中的默认内容类型 application/vnd.spring-boot.actuator.v3+json。没有文档所以我看了代码

@Component
@Endpoint(id = "test")
public class StreamMetrics {

@ReadOperation(produces = "text/event-stream")
public Flux<ServerSentEvent<String>> streamEvents() {
    return Flux.interval(Duration.ofSeconds(1))
            .map(sequence -> ServerSentEvent.<String> builder()
                    .id(String.valueOf(sequence))
                    .event("pingpong")
                    .data("ping")
                    .build());
}

}

spring boot 2 执行器端点不支持服务器发送事件 (SSE)

springboot2 actuator endpoint not supporting Server Sent Event(SSE)

spring-boot-actuator

spring-boot-2