Java多文件生成并压缩下载功能(思路详解)

//思路二：所有都在内存中实现，将生成的多个文件的输出流转换成为byte数组塞入压缩包的输出流中，最后下载该压缩包
    @RequestMapping("/zip/download2")
    public void downloadZip2(String name, HttpServletResponse httpResponse) {
        documentService.downloadReport(name, httpResponse);
    }

public void downloadReport(String name, HttpServletResponse httpResponse){
 
        //使用EasyExcel生成excel表1
        Map excelOut = exportExcel(name);
        //使用EasyExcel生成excel表2（同上）
        Map excelOut2 = exportExcel2(name);
        //将要压缩的文件塞到一个list里面
        List<Map> fileList = new ArrayList();
        fileList.add(excelOut);
        fileList.add(excelOut2);
        //压缩多个文件并下载
        zipFiles(fileList,httpResponse);
    }

 //生成excel表格导出到本地
    public Map exportExcel(String name) {
        List<User> userList = userDao.queryUsersByName(name);
        try (ByteArrayOutputStream out = new ByteArrayOutputStream()) {
            //使用easyExcel导出excel
            String excelFileName = "根据人名查询数据.xlsx";
            ExcelWriter writer = new ExcelWriter(out, ExcelTypeEnum.XLSX, true);
            Sheet sheet = new Sheet(1, 0, User.class);
            //设置自适应宽度
            sheet.setAutoWidth(Boolean.TRUE);
            writer.write(userList, sheet);
            writer.finish();
            Map excelOut = new HashMap();
            excelOut.put("fileName",excelFileName);
            excelOut.put("outByte",out.toByteArray());
            return excelOut;
        } catch (Exception e) {
            log.error(e.getMessage(), e);
        }
        return null;
    }

 //多个文件压缩成压缩包并下载
    public void zipFiles(List<Map> fileList,HttpServletResponse httpResponse) {
        try(ZipOutputStream zipOutputStream = new ZipOutputStream(httpResponse.getOutputStream()); OutputStream out =null) {
            //下载压缩包
            httpResponse.setContentType("application/zip");
            httpResponse.setHeader("Content-Disposition", "attachment;fileName=" + URLEncoder.encode("附件.zip", "UTF-8"));
            // 创建 ZipEntry 对象
            for (Map map:fileList){
                ZipEntry zipEntry =  new ZipEntry((String) map.get("fileName"));
                zipOutputStream.putNextEntry(zipEntry);
                zipOutputStream.write((byte[]) map.get("outByte"));
            }
        } catch (IOException e) {
            log.error(e.getMessage(), e);
        }
    }