springMVC框架网页下载功能实现

       springmvc框架中实现网页下载功能（以导出excel为例）

java后台做法如下：

   public void downLoad(HttpServletRequest request,HttpServletResponse response,HttpSession sesssion){

      

       List<Map<String,Object>>  list=selectData()

;//到数据库中查询需要导出的信息

HSSFWorkbook wb = new HSSFWorkbook();

HSSFSheet sheet = wb.createSheet("导出信息");//excel sheet标题

HSSFRow row = sheet.createRow((int) 0);//创建导出的行数（以0开始）

HSSFCellStyle style = wb.createCellStyle();

         style.setAlignment(HSSFCellStyle.ALIGN_CENTER); // 创建一个居中格式
         HSSFCell cell = row.createCell((short) 0);//创建第一列

cell.setCellValue("数据1");//第一列列名

         cell.setCellStyle(style);//第一列样式（居中）
         cell = row.createCell((short) 1);//创建第二列
         cell.setCellValue("数据2");//第二列列名

         cell.setCellStyle(style);//第二列样式（居中）

for(int i=0;i<list.size();i++){  //给列赋值

                row = sheet.createRow( i + 1);//循环创建
                Map<String,Object> map1=list.get(i);
                row.createCell((short) 0).setCellValue(map1.get(0).toString());//给列赋值
                row.createCell((short) 1).setCellValue(map1.get(1).toString());
               
    }

       try{

FileOutputStream out=new FileOutputStream("下载路径");

           wb.write(out);
           out.close();

           load(request,response,session);//网页下载

 }catch(

Exception e

){

  e.

printStackTrace();

}

}

public void load(HttpServletRequest request,HttpServletResponse response,HttpSession sesssion){

OutputStream outputStream = null;
InputStream inputStream = null;
String rootPath="";
try {
    response.setCharacterEncoding("utf-8");
    //设置文件MIME类型
    response.setContentType("application/octet-stream");
    //设置Content-Disposition
    response.setHeader("Content-Disposition", "attachment;filename=" + new String("导出数据.xls".getBytes("gb2312"), "iso-8859-1"));
    rootPath = "上面下载路径";
    inputStream = new FileInputStream(rootPath);
    outputStream = response.getOutputStream();
    //写文件
    int b;
    while ((b = inputStream.read()) != -1) {
        outputStream.write(b);
    }
} catch (IOException e) {
    e.printStackTrace();
} finally {
    if (inputStream != null)
        try {
            inputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

    if (outputStream != null)//删除原有下载文件
        try {
            outputStream.close();
            File file=new File(rootPath);
            if(file.exists()){
                file.delete();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
}

第二种通用做法：

}