POI之经典案例--按列名导出excel

1.首先要引入jar包（org.apache.poi的jar包最好）

2.直接上代码

public class ExportAction extends ActionSupport {

 private static final Logger logger = LoggerFactory.getActionLog(ExportAction.class);

 private static final long serialVersionUID = 1L;

 

  public void exportDatas(){

      

   List<Map<String,Object>> listBeans=XXX;//该步骤获取需要导出的list集合

   Map<String,String> cloMap=XXX.getAllCloums();//封装map为所有要到处的列，可选择

   HttpServletRequest request = super.getRequest();

   HttpServletResponse response = super.getResponse();//获取struts2的请求

   String filename="导出数据";//设置文件名

   final String userAgent = request.getHeader("USER-AGENT"); 

   try {

       if(userAgent.contains("MSIE")||userAgent.contains("Trident")){ //IE浏览器 

     filename = URLEncoder.encode(filename,"UTF-8");

        filename = StringUtils.replace(filename, "+", "%20");//替换空格

       }else if(userAgent.contains("Mozilla")){   

        filename = new String(filename.getBytes("UTF-8"), "ISO8859-1"); 

       }else{                                                

        filename = URLEncoder.encode(filename,"UTF-8");

        filename = StringUtils.replace(filename, "+", "%20");

       }

   } catch (UnsupportedEncodingException e) {

    e.printStackTrace();

   }

//以上为s判断浏览器兼容性

   response.setContentType("application/vnd.ms-excel;charset=utf-8");

   response.setHeader("Content-disposition", "attachment; filename="+filename+".xls");

   HSSFWorkbook wb = new HSSFWorkbook();

   HSSFSheet  sheet = wb.createSheet(filename);

   HSSFRow row1=sheet.createRow(0);

//以上创建excel工作簿

   int li=0;

   for(String value:cloMap.values()){

    row1.createCell(li).setCellValue(value);

    li++;

   }

//以上为表头

   for(int i=0;i<listBeans.size();i++){

     int col=0;

     HSSFRow row2=sheet.createRow(i+1);

     for(String key:cloMap.keySet()){

     row2.createCell(col).setCellValue(listBeans.get(i).get(key)==null ? "":String.valueOf(listBeans.get(i).get(key)));

     col++;

    }

   }

//以上为逻辑处理

   OutputStream out;

   try {

    out=response.getOutputStream();
    out.flush();

    wb.write(out);

    out.close();

   } catch (IOException e) {

    logger.info("-----Export导出异常------");

   }

         logger.info("-----end ------");

     }

}

//最后在前台通过 window.open 或者window.location.href='',发送请求