数据导出excel等格式文件

@ApiOperation(value = "导出到excel")
    @ApiImplicitParams({
            @ApiImplicitParam(paramType = "query", name = "data", dataType = "String", required = true,
                    value = "name=必填，名称;tp=必填，excel/csv",
                    defaultValue = "{\"ids\":\"1,2\",\"tp\":\"excel\"}")
    })
    @GetMapping("/export")
    public void export(String data) throws IOException {
        String ids = JSON.parseObject(data).getString("ids");
        String tp = JSON.parseObject(data).getString("tp");
        if (StringUtils.isEmpty(ids)) {
            throw new SquirrelRuntimeException(RespConst.NULL, "ids参数为空");
        }
        String[] idArr = ids.split(",");
        List<DataSupplier> list = new ArrayList<>();
        for (String id : idArr) {
            DataSupplier dataSupplier = new DataSupplier();
            dataSupplier.setId(Integer.valueOf(id));
            list.add(dataSupplier);
        }
        List<Integer> lists = new ArrayList<>();
        for (DataSupplier dataSupplier : list) {
            lists.add(dataSupplier.getId());
        }
        List<DataSupplier> page = dataSupplierService.findAllById(lists);

        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        String fileName = "格式_"+ new Date().getTime() + "";
        if (StringUtils.equalsIgnoreCase(tp, "excel")) {
            writeWithHead(page, baos);
            fileName = fileName + ExcelTypeEnum.XLSX.getValue();
        } else {
//            toCsv(page, baos);
            baos.write(JSON.toJSONString(page).getBytes());
            fileName = fileName + ".txt";
        }
        // 获取文件名称，中文可能被URL编码
        fileName = URLDecoder.decode(fileName, "UTF-8");
        byte[] bytes = baos.toByteArray();

        /*
         * 构造响应的头
         */
        HttpHeaders headers = new HttpHeaders();
        // 下载之后需要在请求头中放置文件名，该文件名按照ISO_8859_1编码。
        String filenames = new String(fileName.getBytes(StandardCharsets.UTF_8), StandardCharsets.ISO_8859_1);
        response.setHeader("Content-Disposition", "attachment;filename=" + filenames);
        response.setContentType(MediaType.APPLICATION_OCTET_STREAM_VALUE);
        OutputStream output = response.getOutputStream();
        output.write(bytes);
        output.flush();
        output.close();
    }


    public ByteArrayOutputStream writeWithHead(List<DataSupplier> dList, ByteArrayOutputStream baos) throws IOException {
        Sheet sheet1 = new Sheet(1, 0);
        sheet1.setSheetName("sheet1");
        ExcelWriter writer = new ExcelWriter(baos, ExcelTypeEnum.XLSX);

        List<List<String>> data = new ArrayList<>();
        for (DataSupplier provider : dList) {
            List<String> item = new ArrayList<>();
            item.add(provider.getId() + "");
            item.add(provider.getName());
            item.add(provider.getCode());
            item.add(provider.getSupplyStart() + "");
            item.add(provider.getSupplyEnd() + "");
            item.add(provider.getSignType());
            item.add(provider.getSignDate() + "");
            item.add(provider.getStatus());
            item.add(provider.getStopDate() + "");
            data.add(item);
        }
        List<List<String>> head = new ArrayList<List<String>>();
        List<String> headCoulumn1 = new ArrayList<String>();
        List<String> headCoulumn2 = new ArrayList<String>();


        headCoulumn1.add("id");
        headCoulumn2.add("名称");

        head.add(headCoulumn1);
        head.add(headCoulumn2);


        Table table = new Table(1);
        table.setHead(head);
        writer.write0(data, sheet1, table);
        writer.finish();
        return baos;
    }

    /**
     * @param list
     * @param baos
     * @throws IOException
     */
    private void toCsv(List<DataSupplier> list, ByteArrayOutputStream baos) throws IOException {
//        CsvWriter csvWriter = new CsvWriter(baos, ',', StandardCharsets.UTF_8);
        CsvWriter csvWriter = new CsvWriter(baos, ',', Charset.forName("GBK"));
        //写header
        String[] header = {"id", "名称"};
        csvWriter.writeRecord(header);

        //写内容
        for (DataSupplier item : list) {
            String[] content = {item.getId() + "",
                    item.getName(), item.getCode(), DatetimeUtil.format(item.getSupplyStart(), DatetimeUtil.YYYY_MM_DD_HH_MM_SS),
                    DatetimeUtil.format(item.getSupplyEnd()};

            csvWriter.writeRecord(content);
        }
        csvWriter.close();
    }