Struts2框架中 怎么把从数据库中读取的数据生成文件，并在客户端保存

TestXL.jsp

<%@page  contentType="text/html;  charset=GBK"%>
<%@taglib  uri="/WEB-INF/struts-html.tld"  prefix="html"%>
<html:html>
<html:button  property="button"  onclick="printAll()">DownLoad</html:button>
</html:html>
<script  language='javascript'  type="text/javascript">
function  printAll(){
location.href="<%=request.getContextPath()%>/downloadAction.do";
}
</script>

ExcelBean:

import  java.io.*;
import  jxl.*;
import  jxl.write.*;
import  jxl.format.*;
import  java.util.*;
import  javax.servlet.http.HttpServletResponse;

/*
用于Struts结构中的Excel文件写操作，当但击“导出按钮”时可以直接在客户端导出Excel文件并提示保存
使用方法：
在action类中加入：
ExcelBean  eb  =  new  ExcelBean();
if(vect.size()>0){
eb.exportToExcel(response,  fname,  sheetname,  titles,  vect);  //调用生成excel文件bean
}
参数：
response:action类中的HttpServletResponse;
filename:要生成的保存的缺省的Excel文件名
sheetname:要保存的工作表的名称
titles:工作表中的表格横向标题
vect:数据行
*/

public  class  ExcelBean  {
public  ExcelBean()  {}
public  boolean  exportToExcel(HttpServletResponse  response,String  filename,String  sheetname,String[]  titles,Vector  vect)  throws  Exception  {
OutputStream  os  =  null;
boolean  b1  =  true  ;
try  {
os  =  response.getOutputStream();  //取得输出流
response.reset();  //清空输出流
response.setHeader("Content-disposition","attachment;  filename="  +  filename  +  ".xls");  //设定输出文件头
response.setContentType("application/msexcel");  //定义输出类型
}  catch  (IOException  ex)  {
b1=  false;
System.out.println("流操作错误:"+ex.getMessage());
}
WritableWorkbook  workbook  =  null;
try  {
//创建新的Excel  工作簿
workbook  =  Workbook.createWorkbook(os);
//在Excel工作簿中建一工作表，其名为:第一页
jxl.write.WritableSheet  wsheet  =  workbook.createSheet(sheetname,  0);  //sheet();
WritableFont  font  =  new  WritableFont(WritableFont.ARIAL,  14,
WritableFont.BOLD,  false,
jxl.format.UnderlineStyle.
NO_UNDERLINE,
jxl.format.Colour.BLACK);
WritableCellFormat  format  =  new  WritableCellFormat(font);
for  (int  i  =  0;  i  <  titles.length;  i++)  {
Label  wlabel1  =  new  Label(i,  0,  titles[i],  format);  //行、列、单元格中的文本、文本格式
wsheet.addCell(wlabel1);
}
font  =  new  jxl.write.WritableFont(WritableFont.createFont("宋体"),  12,
WritableFont.NO_BOLD,  false,
jxl.format.UnderlineStyle.
NO_UNDERLINE,
jxl.format.Colour.BLACK);
format  =  new  jxl.write.WritableCellFormat(font);
for  (int  i  =  0;  i  <  vect.size();  i++)  {  //  在索引0的位置创建行（最顶端的行）
String[]  sdata  =  (String[])  vect.elementAt(i);
for  (int  j  =  0;  j  <  sdata.length;  j++)  {  //在索引0的位置创建单元格（左上端）
Label  wlabel1  =  new  Label(j,  i,  sdata[j],  format);  //行、列、单元格中的文本、文本格式
wsheet.addCell(wlabel1);
System.out.println(sdata[j]  +  ":::"  +  sdata[j]);
}
}
workbook.write();  //写入文件
}  catch  (WriteException  ex1)  {
b1  =  false;
System.out.println("WriteException:"+ex1.getMessage());
}  catch  (IOException  ex2)  {
b1  =  false;
System.out.println("IOException:"+ex2.getMessage());
}
workbook.close();
os.close();
return  b1;
}
}

DownloadAction:

import  org.apache.struts.action.*;
import  javax.servlet.http.*;
import  com.segsec.base.ExcelBean;
import  com.segsec.data.basedata;
import  java.util.Vector;

/**
*  <p>Title:DownloadAction  </p>
*  <p>Description:  QRRSMMS  </p>
*  <p>Copyright:  Copyright  (c)  2004  jiahansoft</p>
*  <p>Company:  jiahansoft</p>
*  @author  wanghw
*  @version  1.0
*/

public  class  DownloadAction  extends  Action  {
public  ActionForward  execute(ActionMapping  mapping,
ActionForm  form,
HttpServletRequest  request,
HttpServletResponse  response)  throws  Exception  {
basedata  databean  =  new  basedata();
Vector  vect  =  new  Vector();
boolean  b1=  false;
try  {
String  fname  =  "test";  //Excel文件名
String[]  titles  =  {"车牌号",  "车辆类型",  "用户帐号",  "车台号"};  //标题
String  sheetname  =  "车辆列表";
ExcelBean  eb  =  new  ExcelBean();
vect  =  databean.QuerySimilarVehicleInfoByAdminer();
if(vect.size()>0){
b1  =  eb.exportToExcel(response,  fname,  sheetname,  titles,  vect);  //调用生成excel文件bean
}
}  catch  (Exception  e)  {
System.out.println(e);
}
if(b1){
return  mapping.findForward("display");
}else{
return  mapping.findForward("failure");
}
}
}

basedata:

import  java.sql.PreparedStatement;
import  java.util.Vector;
import  java.sql.DriverManager;
import  java.sql.ResultSet;
import  java.sql.Connection;

public  class  basedata  {
public  Vector  QuerySimilarVehicleInfoByAdminer(){
Vector  vect  =    new  Vector();
int  i  =  0;
Connection  conn  =  null;
PreparedStatement  pstam  =null;
ResultSet  rs  =null;
String  url  =  "jdbc:oracle:thin:@90.0.8.2:1521:ORCL";
String  username  =  "gisap";
String  password  =  "1";
String  drivers  =  "oracle.jdbc.driver.OracleDriver";

String  sqlStr  =  "SELECT    V.NUMBER_PLATE,v.vehicletype,A.ADMINER,U.CALL_LETTER  "
+"  FROM          T_ADMINER_UNIT  AU,T_ADMINER  A,T_VEHICLE  V,T_UNIT  U  "
+"  WHERE        A.ADMINERID=AU.ADMINERID"
+"    AND        A.ADMINER  ='master'  "
+"    AND        AU.UNITID  =  U.UNITID  "
+"    AND        U.UNITID  =  V.UNITID  "
+"  ORDER  BY  V.NUMBER_PLATE  ";
try{
Class.forName(drivers);
conn  =  DriverManager.getConnection(url,  username,  password);
pstam  =  conn.prepareStatement(sqlStr);
rs  =  pstam.executeQuery();
int  collength  =  rs.getMetaData().getColumnCount();
while  (rs.next())  {
collength  =  rs.getMetaData().getColumnCount();
String[]  rowdata  =  new  String[collength];
for  (int  k  =  1;  k  <=  collength;  k++)  {
rowdata[k  -  1]  =  rs.getString(k);  //new  String(rs.getString(k).getBytes("ISO-8859-1"),  "GBK");  //
}
vect.add(rowdata);
}
}catch(Exception  e){
System.out.println("QuerySimilarVehicleInfoByAdminer  Error!"+e.getMessage());
}
finally{
try{
rs.close();
pstam.close();
conn.close();
}catch(Exception  e){}
}
return  vect;
}
public  static  void  main(String[]  args)  {
basedata  basedata  =  new  basedata();
}
}

在struts-config.xml文件的<action-mappings></action-mappings>段中加入：

<action  type="com.segsec.action.DownloadAction"  path="/downloadAction">
<forward  name="display"  path="/welcome.jsp"  />
</action>