java怎么实现读取数据库并生成excel表下载

Question

页面是jsp做的，后台的controller如下所示，为什么我点击前端还是实现不了下载呢？

@RequestMapping(value = "regionInfoDload",method = RequestMethod.GET)
    public void infoDownLoad(Integer regionLevel, HttpServletRequest request, HttpServletResponse response, Model model) {
        System.out.println("从前台获得的regionLevel： " + regionLevel);
        List<TljsjkAjlj15> listTest = tljsjkAjlj15Service.conditionDownload(regionLevel, null,null);
        System.out.println("测试下载查询的数据总量： " + listTest.size());
        //1.创建excel的文档对象
        HSSFWorkbook wb = new HSSFWorkbook();
        //2.创建excel的表单
        HSSFSheet sheet = wb.createSheet("性别");
        //设置行的高度
        //sheet.setColumnWidth(i, 256*18);
        //3.excel字体
        HSSFFont font = wb.createFont();
        //4.excel样式
        HSSFCellStyle style = wb.createCellStyle();
        style.setAlignment(HSSFCellStyle.ALIGN_CENTER); //水平居中对齐
        HSSFRow row = sheet.createRow(1);
        HSSFCell cell = row.createCell(1);
        cell.setCellValue("姓名");
        cell = row.createCell(2);
        cell.setCellValue("身高预测值");
        System.out.println("======================100================");
        for(int i =2;i<listTest.size() + 1;i++) {
            row = sheet.createRow(i);
            cell = row.createCell(1);
            cell.setCellValue(listTest.get(i - 2).getJh() == null ? "":listTest.get(i - 2).getJh());
            cell = row.createCell(2);
            cell.setCellValue(listTest.get(i - 2).getYlmbqYc() == null ? 0: listTest.get(i - 2).getYlmbqYc());
        }
        System.out.println("======================200================");
        try {
            String fileName = new String("运营数据.xls".getBytes("utf-8"),"utf-8");
            response.setContentType("application/octet-stream;charset=utf-8");
            response.setHeader("Content-Disposition", "attachment;filename="+ fileName);
            response.addHeader("Pargam", "no-cache");
            response.addHeader("Cache-Control", "no-cache");
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        System.out.println("======================300================");
        OutputStream os = null;
        try {
            os = response.getOutputStream();
            wb.write(os);
            os.flush();
            Thread.sleep(10000);
            System.out.println("======================400================");
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            if(os != null) {
                try {
                    os.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

从前端发送请求，controller中的的代码执行到：System.out.println("======================400================");这一句，为什么还是实现不了？
大家知道我出错了在哪里吗？抑或大家有什么别的解决方案吗？望请各位路过的大咖不吝赐教。跪谢！

Answer 1

粗略看了下,,看着累,我贴上我的你分析下你的吧,架构SSM
首先前端,自己搞个单击事件就O啦

<a href="/employee/print" class="easyui-linkbutton" iconCls="icon-print" plain="true" data-cmd="print">导出</a>

Controller层

@RequestMapping("/print")
    @ResponseBody
    public void print( HttpServletResponse response) throws IOException {
        // 获取到所有的客服资源池对像
        EmployeeQuery employeeQuery = new EmployeeQuery();
        employeeQuery.setRows(Integer.MAX_VALUE);//设置为最大
        List<Employee> list = employeeService.findPageByQuery(employeeQuery).getRows();//getRows()中的rows是easyui的规定的一个参数也就是获取数据
        // 创建一个Excl表格对象
        HSSFWorkbook wb = new HSSFWorkbook();
        // 建立新的sheet对象（excel的表单）
        HSSFSheet sheet = wb.createSheet("员工Excl表格");
        // 在sheet里创建第二行
        HSSFRow row1 = sheet.createRow(0);
        // 创建第一行设置单元格内容
        row1.createCell(0).setCellValue("员工姓名");
        row1.createCell(1).setCellValue("员工密码");
        row1.createCell(2).setCellValue("职位");
        row1.createCell(3).setCellValue("手机");
        row1.createCell(4).setCellValue("邮件");
        row1.createCell(5).setCellValue("部门");
        row1.createCell(6).setCellValue("入职时间");
        row1.createCell(7).setCellValue("状态");
        row1.createCell(8).setCellValue("性别");

        for (int i = 0; i < list.size(); i++) {
            HSSFRow row = sheet.createRow(i + 1);
            Employee employee = list.get(i);
            // 创建单元格并设置单元格内容
            row.createCell(0).setCellValue(employee.getUsername());//员工姓名
            row.createCell(1).setCellValue(employee.getPassword());//员工密码
            row.createCell(2).setCellValue(employee.getPosition());//职位
            row.createCell(3).setCellValue(employee.getPhone());//手机
            row.createCell(4).setCellValue(employee.getEmail());//邮箱
            //部门
            String name = "";
            try {
                name = employee.getDepartment().getName();
            } catch (Exception e) {

            }
            row.createCell(5).setCellValue(name);
            //入职时间
            String time = "";
            try {
                Date inputTime = employee.getInputTime();
                time = DateUtils.formatDateToString(inputTime, DateUtils.DATE_FORMAT_YMD);// DateUtils是我自己封装的一个时间工具类
            } catch (Exception e) {

            }
            row.createCell(6).setCellValue(time);
            //状态
            String status = "";
            try {
                int num = employee.getStatus();
                if (num == 1) {
                    status = "在职";
                } else if (num == 2) {
                    status = "离职";
                }
            } catch (Exception e) {

            }
            row.createCell(7).setCellValue(status);
            //性别
            String sex = "";
            try {
                int num = employee.getSex();
                if (num == 1) {
                    sex = "男";
                } else if (num == 2) {
                    sex = "女";
                }
            } catch (Exception e) {

            }
            row.createCell(8).setCellValue(sex);
        }

        // 输出Excel文件
        ServletOutputStream outputStream = response.getOutputStream();
        response.reset();
        response.setHeader("Content-disposition", "attachment; filename=details.xls");
        response.setContentType("application/msexcel");
        wb.write(outputStream);
        outputStream.flush();
        outputStream.close();
    }