当文件的内容( Flux<DataBuffer>)包装在另一个对象中时，无法使用WebClient上载文件

import org.springframework.core.io.FileSystemResource;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.http.client.MultipartBodyBuilder;
import org.springframework.http.client.reactive.ReactorClientHttpConnector;
import org.springframework.web.reactive.function.BodyInserters;
import org.springframework.web.reactive.function.client.WebClient;
import reactor.core.publisher.Mono;

import java.io.File;

public class FileUploader {
    private static final String UPLOAD_URL = "https://example.com/upload";

    public static Mono<Void> uploadFile(File file) {
        // Create a WebClient instance with a ReactorClientHttpConnector
        WebClient webClient = WebClient.builder()
                .clientConnector(new ReactorClientHttpConnector())
                .baseUrl(UPLOAD_URL)
                .build();

        // Create a MultipartBodyBuilder to build the request body
        MultipartBodyBuilder bodyBuilder = new MultipartBodyBuilder();
        bodyBuilder.part("file", new FileSystemResource(file))
                .header(HttpHeaders.CONTENT_TYPE, MediaType.MULTIPART_FORM_DATA_VALUE);

        // Make the request and handle the response
        return webClient.post()
                .contentType(MediaType.MULTIPART_FORM_DATA)
                .body(BodyInserters.fromMultipartData(bodyBuilder.build()))
                .exchangeToMono(response -> {
                    // Process the response here
                    if (response.statusCode().is2xxSuccessful()) {
                        return Mono.empty();
                    } else {
                        return Mono.error(new RuntimeException("Failed to upload file: " + response.statusCode()));
                    }
                });
    }
}