HTTP服务器响应404时未调用Spring WebClient异步回调

Question

A problem I encountered is as titled, and the code is below:

Mono<Account> accountMono = client.get()
    .uri("accounturl")
    .accept(MediaType.APPLICATION_JSON)
    .exchange()
    .flatMap(response -> {
                            if (response.statusCode().equals(HttpStatus.OK)) {
                              return response.bodyToMono(Account.class);
                            } else { 
                              return Mono.empty();
                            }
                          });

accountMono.subscribe(result -> callback(result));  

```

Server response 404 . I try to create an empty Account, but the callback() is not called. It looks like the empty Mono is not emitted.

Answer 1

Server response 404, I try to create a empty Account

You're not creating an empty Account . You're returning an empty Mono , ie a Mono that will never emit anything.

If you want to return a Mono which emits an empty Account, then you need

return Mono.just(new Account());