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导出数据为zip压缩文件，解压后为json文件

news 来源：原创 2024/5/15 12:16:16

前端只要将要导出的数据的ids传回后端就行了

比如

    handleExportApp(row) {const ids = row ? [row.id] : this.checkedRows.map(v => v.id); //exportApp为后端导出接口exportApp(ids.join(","));},

后端接口

    public void exportApp(String ids, HttpServletResponse response) {if (StringUtils.isBlank(ids)) {throw new BusinessException("参数不能为空");}List<String> idsList = Arrays.asList(ids.split(","));List<App> list = appService.findAppAllListByIds(idsList);//创建HttpServerResponse的输出流OutputStream out = null;try {out = response.getOutputStream();BufferedInputStream bis;File file = new File("应用数据包.zip");//通过ZipOutputStream定义要写入的对象ZipOutputStream zos = null;zos = new ZipOutputStream(new FileOutputStream(file));writeZos(list, zos);zos.close();//定义返回类型response.setContentType("text/html; charset=UTF-8");response.setContentType("application/octet-stream");response.setHeader("Content-Disposition", "attachment;filename=".concat(String.valueOf(URLEncoder.encode("应用数据包.zip", "UTF-8"))));bis = new BufferedInputStream(new FileInputStream(file));//定义byte，长度就是要转成zip文件的byte长度，避免浪费资源byte[] buffer = new byte[bis.available()];bis.read(buffer);out.flush();out.write(buffer);file.delete();} catch (IOException e) {logger.error("应用数据包流写入异常{}", e.getMessage());throw new BusinessException("系统异常");} finally {if (out != null) {try {out.close();} catch (IOException e) {e.printStackTrace();}}}}public void writeZos(List<App> list, ZipOutputStream zos) {list.forEach(a -> {ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();try {byteArrayOutputStream.write(JSONUtil.toJsonStr(a).getBytes());zos.putNextEntry(new ZipEntry(a.getName() + ".json"));byte[] excelStream = byteArrayOutputStream.toByteArray();zos.write(excelStream);zos.closeEntry();} catch (IOException e) {logger.error("应用数据包流写入异常{}", e.getMessage());throw new BusinessException("系统异常");}});}

拓展
如果只是导出json文件，不需要压缩包的话
前端

    handleExportApp(row) {this.ids = row ? [row.id] : this.checkedRows.map(v => v.id);this.loading = true;this.exportData(this.ids);},exportData(ids) {if (ids.length > 0) {const currentId = ids.shift(); // 取出数组中的第一个idsimulateClick(exportApp(currentId)); // 导出单个数据setTimeout(() => {this.exportData(ids); // 递归调用导出函数，继续下一个数据}, 10000); // 设置递归的间隔时间，以免处理过多数据造成性能问题}},

后端

        if (StringUtils.isBlank(ids)) {throw new BusinessException("参数不能为空");}List<String> idsList = Arrays.asList(ids.split(","));for (String id : idsList) {App app = appService.getById(id);// 忽略未找到的应用程序if (app == null) {continue;}ObjectMapper objectMapper = new ObjectMapper();try {//把对象转成json字符串String jsonString = objectMapper.writeValueAsString(app);// 设置响应头部信息response.setContentType("application/json");response.setCharacterEncoding("UTF-8");response.setHeader("Content-Disposition", "attachment;filename=".concat(String.valueOf(URLEncoder.encode("应用_" + app.getName() + ".json", "UTF-8"))));// 获取输出流并写入JSON字符串PrintWriter writer = response.getWriter();writer.write(jsonString);writer.flush();writer.close();} catch (IOException e) {logger.error("导出应用数据异常：{}", e.getMessage());throw new BusinessException("系统异常");}}

但是这样有一个不好的地方，就是前端用户体验感不是很好，需要等待前端一个个文件导出。