springboot文件上传

 方式1

    @PostMapping("/upload")
    public String uploadFile(@RequestParam("file") MultipartFile file) {
        // 获取上传的文件名
        String fileName = file.getOriginalFilename();

        // 保存文件到指定路径
        try {
            file.transferTo(new File(System.getProperty("user.dir") + "/springboot-file/upload/" + fileName));
            return "文件上传成功！\n\r";
        } catch(IOException e) {
            e.printStackTrace();
            return "文件上传失败！\n\r";
        }
    }

spring:
  # 文件上传配置
  servlet:
    multipart:
      # 是否开启http上传处理
      enabled: true
      # 单个文件最大长度
      max-file-size: 2MB
      # 最大请求文件的大小
      max-request-size: 10MB
      # 设置临时目录
      # location: F://data//temp

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

方式2

    @PostMapping("/upload")
    public String uploadFile(HttpServletRequest request) {
        // 创建一个基于Apache Commons FileUpload的文件上传解析器
        DiskFileItemFactory factory = new DiskFileItemFactory();
        ServletFileUpload fileUpload = new ServletFileUpload(factory);

        // 解析上传的文件数据
        try {
            List<FileItem> items = fileUpload.parseRequest(request);
            for (FileItem item : items) {
                if (!item.isFormField()) {
                    // 获取上传的文件名
                    String fileName = FilenameUtils.getName(item.getName());

                    // 保存文件到指定路径
                    item.write(new File(System.getProperty("user.dir") + "/springboot-file/upload/" + fileName));
                }
            }
            return "文件上传成功！\n\r";
        } catch(Exception e) {
            e.printStackTrace();
            return "文件上传失败！\n\r";
        }
    }

        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.12.0</version>
        </dependency>

 

分片上传

    @PostMapping("/upload")
    public void upload555(HttpServletRequest request, HttpServletResponse response) {
        try {
            // 获取ServletFileUpload
            // 设置缓冲区大小，先读到内存里在从内存写
            DiskFileItemFactory factory = new DiskFileItemFactory();
            factory.setSizeThreshold(1024);
            File fileFolder = new File(System.getProperty("user.dir") + "/springboot-file/upload/");
            // 如果文件夹不存在则创建
            if (!fileFolder.exists() && !fileFolder.isDirectory()) {
                fileFolder.mkdirs();
            }
            factory.setRepository(fileFolder);
            // 解析
            ServletFileUpload servletFileUpload = new ServletFileUpload(factory);
            // 设置单个大小与最大大小
            servletFileUpload.setFileSizeMax(1 * 1024 * 1024 * 1024L);
            servletFileUpload.setSizeMax(10 * 1024 * 1024 * 1024L);



            List<FileItem> items = servletFileUpload.parseRequest(request);
            // 获取文件信息
            UploadFileInfo uploadFileInfo = new UploadFileInfo();
            for (FileItem item : items) {
                if (item.isFormField()) {
                    // 获取分片数据
                    if ("chunk".equals(item.getFieldName())) {
                        uploadFileInfo.setCurrentChunk(Integer.parseInt(item.getString("UTF-8")));
                    }
                    if ("chunks".equals(item.getFieldName())) {
                        uploadFileInfo.setChunks(Integer.parseInt(item.getString("UTF-8")));
                    }
                    if ("name".equals(item.getFieldName())) {
                        uploadFileInfo.setFileName(item.getString("UTF-8"));
                    }
                }
            }



            // 写入临时文件
            // 获取文件基本信息后
            for (FileItem item : items) {
                if (!item.isFormField()) {
                    // 有分片需要临时目录
                    String tempFileName = uploadFileInfo.getFileName();
                    if (StringUtils.isNotBlank(tempFileName)) {
                        if (uploadFileInfo.getCurrentChunk() != null) {
                            tempFileName = uploadFileInfo.getCurrentChunk() + "_" + uploadFileInfo.getFileName();
                        }
                        // 判断文件是否存在
                        File tempFile = new File(System.getProperty("user.dir") + "/springboot-file/upload/", tempFileName);
                        // 断点续传，判断文件是否存在，若存在则不传
                        if (!tempFile.exists()) {
                            item.write(tempFile);
                        }
                    }
                }
            }



            // 判断是否合并
            Integer currentChunk = uploadFileInfo.getCurrentChunk();
            Integer chunks = uploadFileInfo.getChunks();
            String fileName = uploadFileInfo.getFileName();
            // 如果当前分片等于总分片那么合并文件
            if (currentChunk != null && chunks != null && currentChunk.equals(chunks - 1)) {
                File tempFile = new File(System.getProperty("user.dir") + "/springboot-file/upload/", fileName);
                try (BufferedOutputStream os = new BufferedOutputStream(new FileOutputStream(tempFile))) {
                    // 根据之前命名规则找到所有分片
                    for (int i = 0; i < chunks; i++) {
                        File file = new File(System.getProperty("user.dir") + "/springboot-file/upload/", i + "_" + fileName);
                        // 并发情况，需要判断所有，因为可能最后一个分片传完，之前有的还没传完
                        while (!file.exists()) {
                            // 不存在休眠100毫秒后在重新判断
                            Thread.sleep(100);
                        }
                        // 分片存在，读入数组中
                        byte[] bytes = FileUtils.readFileToByteArray(file);
                        os.write(bytes);
                        os.flush();
                        file.delete();
                    }
                    os.flush();
                }
            }



            // 返回结果
            response.setCharacterEncoding("UTF-8");
            response.getWriter().write("上传成功");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }