node转发请求 .csv格式文件下载 中文乱码问题

        let fileUrl = URL + queryString;
        // download file
        let _this = this;

        http.get(fileUrl, function (response) {
　　　　　　　//设置请求头
            _this.res.setHeader(‘Content-disposition‘, ‘attachment; filename=orderData.csv‘);

            response.setEncoding(‘binary‘);  //二进制binary

            var data = ‘‘;
            response.on(‘data‘, function (_data) {    
                data = Buffer.concat([new Buffer(‘binary‘), new Buffer(_data)]);

            }).on(‘end‘, function () {          //加载完

                data = iconv.decode( data.toString(), ‘GBK‘);

                var buffer = new Buffer(data);
                var str=iconv.encode(buffer,‘GBK‘); 

                _this.res.send(str)

            })  
        }) 

  @TSPServiceInfo(name = "OPS.RPA.RecordController.recordListExport", description = "***csv")
    @RequestMapping(value = "/recordListExport", method = RequestMethod.GET)
    @IgnoreResponseLog
    @IgnoreRequestLog
    public String recordListExport(@RequestData RecordListRequestVO requestVO, HttpServletResponse response) throws Exception {
        if (requestVO.getCurrentUserId() == null && StringUtils.isEmpty(requestVO.getCurrentOperatorName())) {
            throw new InvalidParamException("参数错误");
        }

        boolean forUser = requestVO.getCurrentUserId() != null;
        byte[] bytes = recordService.getRecordListBytes(requestVO, forUser);
        if (bytes.length == 0) {
            throw new EmptyResultException("没有查询到记录");
        }
        try (final OutputStream os = response.getOutputStream()) {
            // 写出响应
            HeaderUtil.responseCsvSetter("recordList", response);
            os.write(bytes);
            os.flush();
        } catch (Exception e) {
            LOGGER.error("recordListCsv write response error", e);
            throw new EmptyResultException("结果返回异常");
        }
        return "";
    }
 @Override
    public byte[] getRecordListBytes(RecordListRequestVO request, boolean forUser) {
        RecordListParamEntity param = buildRecordListParam(request, RecordConst.RECORD_TYPE_HISTORY, forUser);

        /**
         * 运营端查看需要筛选用户
         */
        if (!forUser) {
            UserParamEntity userParam = buildUserParam(request);

            if (!BeanUtils.isAllFieldValueNull(userParam)) {
                List<Integer> userIds = userService.getUserIds(userParam);
                if (CollectionUtils.isEmpty(userIds)) {
                    return new byte[0];
                }

                if (userIds.size() < MAX_USER_COUNT) {
                    param.setUserIds(userIds);
                } else {
                    param.setUserType(request.getUserType());
                    param.setUserName(request.getUserName());
                    param.setDisplayId(request.getDisplayId());
                }
            }
        }

        if (recordMapper.count(param) == 0) {
            return new byte[0];
        }

        StringBuilder buf = new StringBuilder();
        String cvsTitle = forUser ? RecordConst.USER_RECORD_LIST_CSV_TITLE : RecordConst.ADMIN_RECORD_LIST_CSV_TITLE;
        buf.append(cvsTitle).append(RecordConst.CSV_RN);

        int offset = 0;
        param.setOffset(offset);
        param.setLimit(SQL_QUERY_LIMIT);
        List<RecordDetailEntity> recordDetails = recordMapper.detailList(param);

        while (!CollectionUtils.isEmpty(recordDetails)) {

            buf.append(convertRecordsToCsvString(recordDetails, forUser));

            offset += SQL_QUERY_LIMIT;
            param.setOffset(offset);
            recordDetails = recordMapper.detailList(param);
        }

        try {
            return buf.toString().getBytes("GBK");
        } catch (UnsupportedEncodingException e) {
            LOGGER.error(e.getMessage(), e);
            return new byte[0];
        }
    }