No data received from endpoint when using Spring WebClient but I can use curl to fetch the data

Question

I have an endpoint which sends out server side events. For testing purposes I have made the endpoint deterministic and the connection to the endpoint terminates after 30 seconds. If I curl the endpoint I get all the data as expected:

$ curl "my/end/point"
data: {"message": "event1"}

data: {"message": "event2"}

data: {"message": "event3"}

data: {"message": "event4"}

...

However, when I use Springs WebClient no data is received. The code I use:

final WebClient webClient = WebClient.create("my/end/point");
final String result = webClient.get()
                               .retrieve()
                               .bodyToFlux(String.class)
                               .blockFirst();
System.out.println(result);

When I run this code I get the following result after 30 seconds:

null

The response code from the request is a 200 OK.

The following example

final StringBuilder result = new StringBuilder();
final URL url = new URL("my/end/point");
final URLConnection conn = url.openConnection();
final BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String line;
while ((line = rd.readLine()) != null) {
    result.append(line);
}
rd.close();
System.out.println(result.toString());

does show the expected result after 30 seconds when run

data: {"message": "event1"}

data: {"message": "event2"}

...

Does anybody know why the result from the WebClient is empty while other methods of fetching the data from the endpoint are not? I'm using java 11 and spring-webflux version 5.1.5.

score 1 · Answer 1 · answered May 24 '19 at 11:11

I solved the issue, instead of doing

final WebClient webClient = WebClient.create("my/end/point");

doing

final WebClient webClient = WebClient.builder()
                                     .clientConnector(new ReactorClientHttpConnector(HttpClient.create()))
                                     .baseUrl(this.legalThingsSocketSettings.getUrl())
                                     .build();

does work, altough I am a bit confused as to why because the ReactorClientHttpConnector should be the default client connector of the WebClient.

No data received from endpoint when using Spring WebClient but I can use curl to fetch the data

1 Answers1