Spring上传和下载以及Feign调用时操作

灰太狼 2024-03-26 11:22 9阅读 0赞

**一、上传文件（以批次为例）**

A服务（服务提供者）

控制层：

@ApiOperation("批量文件上传")
        @PostMapping("/uploadFiles")
        //响应的是k:文件名 v:文件存储路径
        public JsonResult<Map<String,String>> uploadFiles(@RequestParam("files") MultipartFile[] files) throws IOException {
            return JsonResultTool.success(fileService.uploadFiles(files));
        }
    
        @ApiOperation("单个文件上传")
        @PostMapping(value = "/uploadFile",consumes = {MediaType.MULTIPART_FORM_DATA_VALUE})
        public JsonResult<String> uploadFile(@RequestParam("file") MultipartFile file) throws IOException {
            return JsonResultTool.success(fileService.uploadFile(file));
        }

业务层：

//类常量引用
        @Resource
        MultipartConfigElement config;
    
        @Override
        public Map<String, String> uploadFiles(MultipartFile[] files) throws IOException {
            if (files == null ||files.length == 0) {
                return null;
            }
            Map<String, String> map = new HashMap<>();
            for (MultipartFile file : files) {
                if (!file.isEmpty()) {
                    //获取默认的绝对路径
                    String localtion = config.getLocation();
                    //创建自定义路径并返回路径字符串        
                    String fileDir = FileUploadUtils.uploadFile(localtion, file);
                    map.put(file.getOriginalFilename(), fileDir);
                }
            }
            return map;
        }
    
    
        //可以自己写一个配置类文件或者直接放在启动类（配置的目的还是自己定义绝对路径）
        @Bean
        MultipartConfigElement multipartConfigElement() {
            MultipartConfigFactory factory = new MultipartConfigFactory();
            String osName = System.getProperty("os.name").toLowerCase();
            String path = "";
            if( osName.indexOf(WINDOWS) >= 0){
                path = "d:/data/temp/";
            }else{
                path = "/root/data/temp";
            }
            if(!FileUtil.exist(path)){
                FileUtil.mkdir(path);
            }
            factory.setLocation(path);
            factory.setMaxFileSize(DataSize.parse(maxFileSize));
            factory.setMaxRequestSize(DataSize.parse(maxRequestSize));
            return factory.createMultipartConfig();
        }

/**
         * 根据文件路径上传
         *
         * @param baseDir 相对应用的基目录
         * @param file    上传的文件
         * @return 文件名称
         * @throws IOException
         */
        public static final String uploadFile(String baseDir, MultipartFile file) throws IOException {
            return upload(baseDir, file);
        }
    
        /**
         * 文件上传
         *
         * @param baseDir   相对应用的基目录
         * @param file      上传的文件
         * @return 返回上传成功的文件名
         * @throws IOException 异常
         */
        public static final String upload(String baseDir, MultipartFile file) throws IOException{
    
            String fileName = file.getOriginalFilename();
            //校验文件名称长度
            checkFileNameLength(fileName);
            //获取保存的目录路径
            String fileDir = getFileDir(baseDir, fileName);
            //写文件
            file.transferTo(new File(fileDir,fileName));
            return fileDir;
        }
    
        /**
         * 检查文件名称长度
         * @param fileName 文件名称
         */
        public static final void checkFileNameLength(String fileName) {
            if (fileName.length() > FileUploadUtils.DEFAULT_FILE_NAME_LENGTH) {
                throw new FileException(FileExceptionEnums.FILE_NAME_TOO_LONG);
            }
        }
    
        /**
         * 生成文件路径
         * */
        private static final String getFileDir(String uploadDir, String fileName) {
            String ext = FileUtil.extName(fileName);
            String datePath = DateUtils.datePath();
            //储存路径
            StringBuilder path = new StringBuilder();
            path.append(uploadDir).append(datePath).append("/").append(ext).append("/");
            //path一定是绝对路径例如d:xxx/xxx或者linux root/xx/xx  否则会提示异常
            File fileDir = new File(path.toString());
            if (!fileDir.exists()){
                fileDir.mkdirs();
            }
            return path.toString();
        }

如果无需跨服务调用，到此上传结束！！！！

跨服务调用（消费服务B调用A服务接口）：

Feign：

@PostMapping(value = "/filesystem/uploadFiles",consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
        JsonResult<Map<String,String>> uploadFiles(@RequestPart("files") MultipartFile[] files) throws IOException;
     
    //备注：以上批次接口我没有测试过，不好判断
    
        
        //单个文件的调用
        @PostMapping(value = "/filesystem/uploadFile",consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
        JsonResult<String> uploadFile(@RequestPart("file") MultipartFile file) throws IOException;
    
    //备注：使用@RequestPart 不要使用@RequestParam
    //consumes = MediaType.MULTIPART_FORM_DATA_VALUE 不要忘记

B服务的实现不多介绍

**二、下载文件**

推荐两种方式：

方式一：java通用下载

服务提供层A:

@ApiOperation("下载单个文件")
        @GetMapping("/downloadFile")
        public void downloadFile(String path, String fileName, HttpServletResponse response){
            fileService.downloadFile(path, fileName, response);
        }

@Override
        public void downloadFile(String path,String fileName, HttpServletResponse response) {
            //获取文件
            File file=  getFile(path, fileName);
            if(file == null) {
                throw new FileException(FileExceptionEnums.FILE_NOT_FOUND);
            }
    
            //1 设置response 响应头
            response.reset();
            response.setCharacterEncoding("UTF-8");
            //2 设置响应文本类型，以xlsx格式为例（可以参考：https://blog.csdn.net/josavion/article/details/115260427）
            response.setContentType("application/octet-stream");
            //fileName我的文件名带后缀的，如果无后缀，这里要补齐"attachment;filename="+ fileName + ".xlsx"
            response.setHeader("Content-Disposition",
                    "attachment;filename="+ fileName);
            try {
                //读取文件--输入流
                InputStream input = new FileInputStream(file);
                BufferedInputStream bufferedInputStream = new BufferedInputStream(input);
                //写出文件--输出流
                BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(response.getOutputStream());
                int length = 0;
                byte[] temp = new byte[1024 * 10];
                while ((length = bufferedInputStream.read(temp)) != -1) {
                    bufferedOutputStream.write(temp, 0, length);
                }
                bufferedOutputStream.flush();
                bufferedOutputStream.close();
                bufferedInputStream.close();
                input.close();
            } catch (IOException e) {
                log.error("文件:{}下载失败,",fileName,e);
                throw new FileException(FileExceptionEnums.DOWN_LOAD_ERROR);
            }
        }
    
        private File getFile(String path, String fileName) {
            File file = new File(path + fileName);
            if (!(file.exists() && file.canRead())) {
                return null;
            }
            return file;
        }

Feign：

@GetMapping("/filesystem/downloadFile")
        //返回的是Response 
        Response downloadFile(@RequestParam("path") String path, @RequestParam("fileName") String fileName);

B调用A：

@Override
        public void getFile(String path, String fileName, HttpServletResponse response) throws IOException {
            InputStream inputStream = null;
            Response serviceResponse = fileClient.downloadFile(path, fileName);
            //获取body
            Response.Body body = serviceResponse.body();
            //输入流
            inputStream = body.asInputStream();
            BufferedInputStream bufferedInputStream = new BufferedInputStream(inputStream);
            response.setHeader("Content-Disposition", "attachment; filename=" + fileName);
            //输出流
            BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(response.getOutputStream());
            int length = 0;
            byte[] temp = new byte[1024 * 10];
            while ((length = bufferedInputStream.read(temp)) != -1) {
                bufferedOutputStream.write(temp, 0, length);
            }
            bufferedOutputStream.flush();
            bufferedOutputStream.close();
            bufferedInputStream.close();
            inputStream.close();
        }

**方式二：基于ResponseEntity实现(建议)**

A服务：

@ApiOperation("下载单个文件")
        @GetMapping("/downloadFileBytes")
        public ResponseEntity<byte[]> downloadFileBytes(String path, String fileName) throws IOException {
            return fileService.downloadFileBytes(path, fileName);
        }
    
    //业务层
        @Override
        public ResponseEntity<byte[]> downloadFileBytes(String path, String fileName) throws IOException {
            File file=  getFile(path, fileName);
            if(file == null) {
                throw new FileException(FileExceptionEnums.FILE_NOT_FOUND);
            }
            HttpHeaders headers = new HttpHeaders();
            String filename = new String(fileName.getBytes("utf-8"),"iso-8859-1");
            headers.setContentDispositionFormData("attachment", filename);
            //感兴趣的可以去看一下MediaType
            headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
            return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(file),headers, HttpStatus.CREATED);
        }
    
        private File getFile(String path, String fileName) {
            File file = new File(path + fileName);
            if (!(file.exists() && file.canRead())) {
                return null;
            }
            return file;
        }

Feign:

@GetMapping("/filesystem/downloadFileBytes")
        ResponseEntity<byte[]> downloadFileBytes(@RequestParam("path") String path, @RequestParam("fileName") String fileName) throws IOException;

B调用A:

@Override
        public ResponseEntity<byte[]> getFileBytes(String path, String fileName) throws IOException {
            String resourceName = report.getFileName();
            ResponseEntity<byte[]> data = fileClient.downloadFileBytes(path,fileName);
            return data;
        }