poi实现从数据库到excel的导出

网上下载poi的jar包:http://apache.justdn.org/jakarta/poi/

2.在sturts的Action里的代码如下：

本例子实现把list中的数据导出到excel

/*
* Generated by MyEclipse Struts
* Template path: templates/java/JavaClass.vtl
*/
package sso.admin.action;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionMessage;
import org.apache.struts.action.ActionMessages;

import sso.admin.form.DataOutForm;
import sso.admin.recruitinfo.*;
import sso.admin.subject.*;
import sso.admin.department.*;
import sso.common.CommonUtil;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;

import org.apache.poi.hssf.usermodel.HSSFSheet;

import org.apache.poi.hssf.usermodel.HSSFRow;

import org.apache.poi.hssf.usermodel.HSSFCell;

import java.io.FileOutputStream;
import java.util.*;

/**
*designby Mr.Chan

* Creation date: 12-28-2007
*
* XDoclet definition:
* @struts.action path="/dataOut" name="dataOutForm" input="/form/dataOut.jsp" scope="request" validate="true"
*/
public class DataOutAction extends Action {
/*
* Generated Methods
*/

/**
* Method execute
* @param mapping
* @param form
* @param request
* @param response
* @return ActionForward
*/
public ActionForward execute(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response) {
DataOutForm dof = (DataOutForm) form;// TODO Auto-generated method stub
ActionMessages errors = new ActionMessages() ;
errors.add("error",new ActionMessage("download_file")) ;
super.saveErrors(request, errors);
String yxdm="";
String zydm="";
if(dof.getYxdm()!=null){
yxdm=dof.getYxdm();
}
if(dof.getZydm()!=null){
zydm=dof.getZydm();
}
String realPath=request.getRealPath("");
int checkNum=Integer.parseInt(dof.getCheckNum());
List l=null;
RecruitInfoOperation rio=new RecruitInfoOperation();
if(yxdm.equals("")&&zydm.equals("")){
l=rio.queryAllRegStuInfo(checkNum);
}else{
l=rio.queryRegStuInfoBySubject(checkNum,zydm, yxdm);
}
//Excel 文件要存放的位置，假定在sso的download目录下
String outputFile=realPath+"/download/temp.xls";
SubjectOperation so=new SubjectOperation();
DepartmentOperation deo=new DepartmentOperation();
try{
//创建新的Excel 工作簿
HSSFWorkbook workbook = new HSSFWorkbook();
//在Excel工作簿中建一名为"报到新生"的工作表，其语句为：
//HSSFSheet sheet = workbook.createSheet("新生报到状况表");
HSSFSheet sheet=null;
if(checkNum==1){
sheet = workbook.createSheet("报到新生");
}else{
sheet = workbook.createSheet("未报到新生");
}
//在索引0的位置创建行（最顶端的行）
HSSFRow row = sheet.createRow((short)0);
//在索引0的位置创建单元格（左上端）
row.createCell((short)0).setCellValue("考生号");
row.createCell((short)1).setCellValue("姓名");
row.createCell((short)2).setCellValue("学号");
row.createCell((short)3).setCellValue("系别");
row.createCell((short)4).setCellValue("专业");
row.createCell((short)5).setCellValue("考分");
row.createCell((short)6).setCellValue("家庭住址");
for(int i=0;i<l.size();i++){
HSSFRow row1 = sheet.createRow((short)(i+1));
Object temp=(Object)l.get(i);
String ksh=temp.toString();
YX_RegBean yx_reg=(YX_RegBean)rio.queryXsByKsh(ksh);
String subject=null;
String department=null;
SubjectBean sb=new SubjectBean();
DepartmentBean db=new DepartmentBean();
if(yx_reg.getZydm()==null)
{
subject="未添加";
}
else{
sb=(SubjectBean)so.queryById(yx_reg.getZydm());
subject=CommonUtil.isoToGb(sb.getName());
}
if(yx_reg.getYxdm()==null)
{
department="未添加";
}
else{
db=(DepartmentBean)deo.queryById(yx_reg.getYxdm());
department=CommonUtil.isoToGb(db.getGroupName());
}
row1.createCell((short)0).setCellValue(yx_reg.getKsh());
row1.createCell((short)1).setCellValue(CommonUtil.isoToGb(yx_reg.getXm()));
row1.createCell((short)2).setCellValue(yx_reg.getXh());
row1.createCell((short)3).setCellValue(department);
row1.createCell((short)4).setCellValue(subject);
row1.createCell((short)5).setCellValue(yx_reg.getZf());
row1.createCell((short)6).setCellValue(CommonUtil.isoToGb(yx_reg.getJtzz()));
subject=null;
department=null;
System.gc();
yx_reg=null;
System.gc();
}
//新建一输出文件流
FileOutputStream fOut = new FileOutputStream(outputFile);
//把相应的Excel 工作簿存盘
workbook.write(fOut);
fOut.flush();
//操作结束，关闭文件
fOut.close();
return mapping.getInputForward();
}catch(Exception e) {
System.out.println(e+"出错拉");
return null;
}

}
}