java浏览器单文件下载,批量文件压缩下载

￡神魔★判官ぃ 2023-10-09 23:09 49阅读 0赞

直接上代码

@GetMapping("/fileDownLoad")
        public void fileDownLoad(@Param("ids") String ids, HttpServletRequest request, HttpServletResponse response) throws Exception {
    
            //List<String> list = Arrays.asList("D:\\a.docx", "D:\\c\\b.docx", "D:\\c\\p.docx");
            List<String> list = Arrays.asList("D:\\a.docx");
    
            if (CollectionUtils.isEmpty(list)){
                throw new Exception("请选择要下载文件/图片");
            }
    
            //设置响应头信息
            response.reset();
            response.setCharacterEncoding("utf-8");
            response.setContentType("multipart/form-data");
            //设置压缩包的名字，date为时间戳
            String date = String.valueOf(System.currentTimeMillis());
            String downloadName = "压缩包" + date + ".zip";
            //返回客户端浏览器的版本号、类型
            String agent = request.getHeader("USER-AGENT");
            try {
                //针对IE或者以IE为内核的浏览器：
                if (agent.contains("MSIE") || agent.contains("Trident")) {
                    downloadName = URLEncoder.encode(downloadName, "UTF-8");
                } else {
                    //非IE浏览器的处理：
                    downloadName = new String(downloadName.getBytes(StandardCharsets.UTF_8), StandardCharsets.ISO_8859_1);
                }
            } catch (Exception e) {
                log.error("系统异常", e);
            }
    
            if (list.size()>1){
                //多文件/图压缩下载
                batchFileDownLoad(list,downloadName,response);
    
            }else {
                //单文件/图直接下载
                singleFileDownLoad(list,response);
    
            }
        }

> 多文件/图压缩下载

/**
         *  多文件/图压缩下载
         * @param list 文件/图片路径
         * @param downloadName 压缩包名
         * @param response
         */
        private void batchFileDownLoad(List<String> list, String downloadName, HttpServletResponse response) {
            //设置压缩包名称
            response.setHeader("Content-Disposition", "attachment;fileName=\"" + downloadName + "\"");
            //设置压缩流：直接写入response，实现边压缩边下载
            ZipOutputStream zipOs = null;
            //循环将文件写入压缩流
            DataOutputStream os = null;
    
            try {
                zipOs = new ZipOutputStream(new BufferedOutputStream(response.getOutputStream()));
                //设置压缩方法
                zipOs.setMethod(ZipOutputStream.DEFLATED);
                //遍历文件信息（主要获取文件名/文件路径等）
                for (String t : list) {
                    try {
                        //文件存储路径
                        String path = t;
                        //压缩文件中每个文件的文件名称
                        String name = t.substring(t.lastIndexOf("\\")+1);
                        log.info("batchDownloadFile:[filePath:{}]", path);
                        File file = new File(path);
                        if (!file.exists()) {
                            throw new RuntimeException("文件不存在");
                        }
                        FileInputStream fs = null;
                        try {
                            //添加ZipEntry，并将ZipEntry中写入文件流
                            zipOs.putNextEntry(new ZipEntry(name));
                            os = new DataOutputStream(zipOs);
                            fs = new FileInputStream(file);
                            byte[] b = new byte[100];
                            int length;
                            //读入需要下载的文件的内容，打包到zip文件
                            while ((length = fs.read(b)) != -1) {
                                os.write(b, 0, length);
                            }
                        } catch (Exception e) {
                            log.error("系统异常", e);
                        } finally {
                            //关闭流
                            assert fs != null;
                            fs.close();
                            zipOs.closeEntry();
                        }
    
                    } catch (Exception e) {
                        log.error("下载文件出错![{}]", e.getMessage());
                    }
                }
            } catch (Exception e) {
                log.error("系统异常", e);
            } finally {
                //关闭流
                try {
                    if (os != null) {
                        os.flush();
                        os.close();
                    }
                    if (zipOs != null) {
                        zipOs.close();
                    }
                } catch (IOException e) {
                    log.error("系统异常", e);
                }
            }
        }

> 单文件/图直接下载

/**
         * 单文件直接下载
         * @param list 文件/图片路径
         * @param response
         */
        private void singleFileDownLoad(List<String> list, HttpServletResponse response) {
    
            FileInputStream fis = null;
            OutputStream out = null;
            String path = list.get(0);
            String name = path.substring(path.lastIndexOf("\\")+1);
            response.setHeader("Content-Disposition", "attachment;filename="+name);
            try {
                fis = new FileInputStream(path);
                out = response.getOutputStream();
                byte[] b = new byte[1024];
                int len = 0;
                while((len = fis.read(b))!=-1){
                    out.write(b, 0, len);
                }
            }catch (Exception e){
                e.printStackTrace();
            }finally {
                try {
                    if (out != null) {
                        out.flush();
                        out.close();
                    }
                    if (fis != null) {
                        fis.close();
                    }
                } catch (IOException ex) {
                    log.error("系统异常", ex);
                }
            }
    
        }

参考:[JAVA后台实现文件批量下载\_java批量下载文件\_utada hikki的博客-CSDN博客][JAVA_java_utada hikki_-CSDN]

[JAVA_java_utada hikki_-CSDN]: https://blog.csdn.net/mrxutada/article/details/118808880