java怎么实现文件上传功能 实现后端文件上传接口的常见方法

@RestController

public class FileUploadController {

    @PostMapping("/upload")

    public String uploadFile(@RequestParam("file") MultipartFile file) {

        if (file.isEmpty()) {

            return "请选择文件";

        }

        try {

            // 保存文件到指定路径

            String fileName = file.getOriginalFilename();

            Path path = Paths.get("uploads/" + fileName);

            Files.write(path, file.getBytes());

            return "文件上传成功: " + fileName;

        } catch (IOException e) {

            return "上传失败: " + e.getMessage();

        }

    }

}

spring:

  servlet:

    multipart:

      max-file-size: 10MB

      max-request-size: 10MB

@WebServlet("/upload")

@MultipartConfig

public class UploadServlet extends HttpServlet {

    protected void doPost(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {

        Part filePart = request.getPart("file");

        String fileName = filePart.getSubmittedFileName();

        filePart.write("uploads/" + fileName);

        response.getWriter().println("文件上传成功：" + fileName);

    }

}

@PostMapping("/upload-multiple")

public String uploadFiles(@RequestParam("files") MultipartFile[] files) {

    for (MultipartFile file : files) {

        if (!file.isEmpty()) {

            try {

                Path path = Paths.get("uploads/" + file.getOriginalFilename());

                Files.write(path, file.getBytes());

            } catch (IOException e) {

                return "部分文件上传失败";

            }

        }

    }

    return "全部文件上传成功";

}