如何在spring boot中使用MultipartFile加载本地文件

import org.springframework.web.multipart.MultipartFile;
import org.springframework.util.StringUtils;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.StandardCopyOption;
import java.io.IOException;

@RestController
public class FileUploadController {

    private static final String UPLOAD_DIR = "path/to/upload/directory"; // 设置上传文件保存的目录

    @PostMapping("/upload")
    public String uploadFile(@RequestParam("file") MultipartFile file) {
        // 检查文件是否为空
        if (file.isEmpty()) {
            return "请选择要上传的文件";
        }

        try {
            // 获取文件名
            String fileName = StringUtils.cleanPath(file.getOriginalFilename());

            // 设置文件保存的路径
            Path uploadPath = Paths.get(UPLOAD_DIR).toAbsolutePath().normalize();
            
            // 确保保存文件的目录存在，如果不存在则创建
            Files.createDirectories(uploadPath);

            // 将文件保存到本地
            Path targetLocation = uploadPath.resolve(fileName);
            Files.copy(file.getInputStream(), targetLocation, StandardCopyOption.REPLACE_EXISTING);

            return "文件上传成功！";
        } catch (IOException e) {
            e.printStackTrace();
            return "文件上传失败！";
        }
    }
}