Excel导出文件流下载

@CrossOrigin(allowCredentials="true", allowedHeaders="*", methods={RequestMethod.GET,  
            RequestMethod.POST, RequestMethod.DELETE, RequestMethod.OPTIONS,  
            RequestMethod.HEAD, RequestMethod.PUT, RequestMethod.PATCH}, origins="*")
    @RequestMapping("/ot")
    @ResponseBody
    public void ot(String key, HttpServletResponse response) {
        try {
            String storeName = key+".xlsx";
            XSSFWorkbook workBook = excelService.outputExcel(key);
            ByteArrayOutputStream bt = new ByteArrayOutputStream();
            workBook.write(bt);
            workBook.close();
            bt.flush();
            ByteArrayInputStream bis = new ByteArrayInputStream(bt.toByteArray());
            response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");  
            response.setHeader("Content-disposition", "attachment; filename="  
                + new String(storeName.getBytes("utf-8"), "ISO8859-1")); 
            //设置输出长度
            response.setHeader("Content-Length", String.valueOf(bt.size()));
            BufferedOutputStream bos = new BufferedOutputStream(response.getOutputStream());
            byte[] buff = new byte[2048];  
            int bytesRead;  
            while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {  
              bos.write(buff, 0, bytesRead);  
            }  
            //关闭流
            bis.close();  
            bos.close();  
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

public XSSFWorkbook outputExcel(String key){
        String json = "{status:‘OK‘, msg: ‘导出完毕！‘}";
        
        String schame = key.split("\\.")[0];
        String tablename = key.split("\\.")[1];
        XSSFWorkbook workBook = new XSSFWorkbook();
        XSSFSheet sheet = workBook.createSheet();
        workBook.setSheetName(0,"Sheet1");
        XSSFRow titleRow = sheet.createRow(0);
        titleRow.createCell(0).setCellValue(tablename);
        Jedis jedis = new Jedis("10.8.4.94");
        List<String> tables = new ArrayList<String>();
        jedis.select(2);
        try {
            tables = jedis.lrange("db_tables", 0, -1);
        } catch (Exception e) {
            // TODO: handle exception
        }finally{
            jedis.close();
        }
        
        for(String s:tables){
            JSONObject obj = JSON.parseObject(s);
            if(obj.getString("owner").equals(schame) && obj.getString("table_name").equals(tablename)){
                titleRow.createCell(1).setCellValue(obj.getString("comment"));
            }
        }
        
        XSSFRow secondRow = sheet.createRow(1);
        secondRow.createCell(0).setCellValue("字段英文名");
        secondRow.createCell(1).setCellValue("字段类型");
        secondRow.createCell(2).setCellValue("注释");
        secondRow.createCell(3).setCellValue("是否主键");
        secondRow.createCell(4).setCellValue("是否非空");
        secondRow.createCell(5).setCellValue("默认值");
        
        jedis = new Jedis("10.8.4.94");
        List<String> columns = new ArrayList<String>();
        jedis.select(2);
        try {
            columns = jedis.lrange(key, 0, -1);
        } catch (Exception e) {
            // TODO: handle exception
        }finally{
            jedis.close();
        }
        
        int k = 2;
        for(String s: columns){
            JSONObject obj = JSON.parseObject(s);
            XSSFRow row = sheet.createRow(k);
            row.createCell(0).setCellValue(obj.getString("column_name"));
            row.createCell(1).setCellValue(obj.getString("data_type").equals("VARCHAR2")?(obj.getString("data_type")+"("+obj.getString("data_length")+")"):obj.getString("data_type"));
            row.createCell(2).setCellValue(obj.getString("comment"));
            row.createCell(3).setCellValue(obj.getString("pk"));
            row.createCell(4).setCellValue(obj.getString("nullable"));
            row.createCell(5).setCellValue(obj.getString("data_default"));
            k++;
        }
        
        return workBook;
    }