使用Spring WebClient重试时添加新标头

import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpRequest;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.ClientHttpRequestExecution;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.web.reactive.function.client.ExchangeFilterFunction;
import reactor.core.publisher.Mono;

public class CustomRetryFilter implements ExchangeFilterFunction {

    private static final int MAX_RETRIES = 3;

    @Override
    public Mono<ClientHttpResponse> filter(HttpRequest request, ExchangeFunction next) {
        return next.exchange(request)
                .retry(MAX_RETRIES, this::shouldRetry);
    }

    private Mono<? extends Throwable> shouldRetry(Throwable throwable) {
        // Add your retry condition here
        // For example, retry on specific status codes
        if (throwable instanceof WebClientResponseException) {
            WebClientResponseException responseException = (WebClientResponseException) throwable;
            HttpStatus statusCode = responseException.getStatusCode();
            if (statusCode == HttpStatus.SERVICE_UNAVAILABLE || statusCode == HttpStatus.GATEWAY_TIMEOUT) {
                return Mono.just(throwable);
            }
        }
        return Mono.error(throwable);
    }
}

import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.web.reactive.function.client.WebClient;

public class ExampleClient {

    private static final String API_URL = "https://example.com/api";

    public static void main(String[] args) {
        WebClient webClient = WebClient.builder()
                .baseUrl(API_URL)
                .defaultHeader(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE)
                .filter(new CustomRetryFilter())
                .build();

        // Make requests using the WebClient
        // ...
    }
}