发送带有MultipartFile字段的对象列表，返回415不支持的媒体类型

import org.springframework.core.io.ByteArrayResource;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.util.MultiValueMap;
import org.springframework.web.client.RestTemplate;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;

public class FileUploadExample {
    public static void main(String[] args) throws IOException {
        // 创建一个RestTemplate对象
        RestTemplate restTemplate = new RestTemplate();

        // 设置请求头
        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.MULTIPART_FORM_DATA);

        // 创建一个MultiValueMap对象，用于存储请求体的各个字段
        MultiValueMap<String, Object> body = new LinkedMultiValueMap<>();

        // 读取文件并转换为ByteArrayResource对象
        Path filePath1 = Paths.get("path/to/file1.txt");
        byte[] fileBytes1 = Files.readAllBytes(filePath1);
        ByteArrayResource fileResource1 = new ByteArrayResource(fileBytes1) {
            @Override
            public String getFilename() {
                return "file1.txt";
            }
        };

        Path filePath2 = Paths.get("path/to/file2.txt");
        byte[] fileBytes2 = Files.readAllBytes(filePath2);
        ByteArrayResource fileResource2 = new ByteArrayResource(fileBytes2) {
            @Override
            public String getFilename() {
                return "file2.txt";
            }
        };

        // 将文件资源添加到请求体中
        body.add("files", fileResource1);
        body.add("files", fileResource2);

        // 创建HttpEntity对象，将请求头和请求体封装起来
        HttpEntity<MultiValueMap<String, Object>> requestEntity = new HttpEntity<>(body, headers);

        // 发送POST请求
        String url = "http://example.com/upload";
        ResponseEntity<String> response = restTemplate.postForEntity(url, requestEntity, String.class);

        // 处理返回结果
        if (response.getStatusCode().is2xxSuccessful()) {
            System.out.println("文件上传成功！");
        } else {
            System.out.println("文件上传失败！");
        }
    }
}