前两天公司的同事用java　jxl写了一段导出excel的代码，值得学习，现提供代码如下：（导出一个list,要作到 iterator）
首先导出jxl.jar，然后方法如下：
/**
  * @param mapping
  * @param form
  * @param request
  * @param response
  * @return ActionForward 得到输入的起始客户代码和结束客户代码,查询结算清单，返回结果
  */
 public void doExportAsXLS(ActionMapping mapping, ActionForm form,
   HttpServletRequest request, HttpServletResponse response) {
  String userCodeBegin = request.getParameter("uCodeBegin");
  String userCodeEnd = request.getParameter("uCodeEnd");
  log.info("userCodeBegin " + userCodeBegin.toString());
  log.info("userCodeEnd " + userCodeEnd.toString());
  if (userCodeBegin == null || userCodeBegin.equals("")) {
   userCodeBegin = userCodeEnd;
  }
  if (userCodeEnd == null || userCodeEnd.equals("")) {
   userCodeEnd = userCodeBegin;
  }
  List balanceList = settleService.getSettleBill(userCodeBegin,
    userCodeEnd);

  OutputStream os = null;
  WritableWorkbook wwb = null;
  Date date = new Date();
  Format format = new SimpleDateFormat("yyyyMMdd");
  String strDate = format.format(date);
  try {

   os = new FileOutputStream(strDate + "settle.xls");
   wwb = Workbook.createWorkbook(os);
   Iterator it = balanceList.iterator();
            doConfigExcel (it, wwb);
  } catch (Exception e) {

  } finally {
   try {
    wwb.write();
    wwb.close();
    os.close();
   } catch (Exception e) {
    e.printStackTrace();
   }

  }

  response.setHeader("Content-disposition", "attachment;filename="
    + strDate + "settle.xls\"");
  response.setContentType("application/msexcel");
  try {
   FileInputStream fileInputStream = new FileInputStream(strDate
     + "settle.xls");
   OutputStream out = response.getOutputStream();
   int i = 0;
   while ((i = fileInputStream.read()) != -1) {
    out.write(i);
   }
   fileInputStream.close();
  } catch (FileNotFoundException e) {
   e.printStackTrace();
  } catch (IOException e) {
   e.printStackTrace();
  }

 }

private void doConfigExcel (Iterator it, WritableWorkbook wwb) {
  
  
  try {
   
   
   while (it.hasNext()) {
    Label lchild;
    SettleVo sv = (SettleVo) it.next();
    String userCode = sv.getUserCode();
    int i = 2;
    int j = 0;
    WritableFont wf = new WritableFont(WritableFont.TIMES, 18, WritableFont.BOLD, true);
    WritableCellFormat wcfF = new WritableCellFormat(wf);
    
    WritableSheet ws = wwb.createSheet(userCode, 0);
    Label labelMain = new Label(4, 0, "中国玉米淀粉网 -- 客户结算清单",wcfF);
    
    Label labelMain1 = new Label(4, 1, "客户结算清单",wcfF);
    ws.addCell(labelMain);
    ws.addCell(labelMain1);
    lchild = new Label(0, 2, "客户代码");

    
    ws.addCell(lchild);

    lchild = new Label(0, 3, userCode);
    ws.addCell(lchild);

    String code = sv.getCode();
    lchild = new Label(2, 2, "摊位代码");
    ws.addCell(lchild);
    lchild = new Label(2, 3, code);
    ws.addCell(lchild);

    String fdate = sv.getFormatDate();
    lchild = new Label(4, 2, "日期");
    ws.addCell(lchild);
    lchild = new Label(4, 3, fdate);
    ws.addCell(lchild);

    lchild = new Label(4, 4, "当日成交清单",wcfF);
    ws.addCell(lchild);

    Iterator its = sv.getOrders().iterator();
    lchild = new Label(0, 5, "序 号");
    ws.addCell(lchild);
    lchild = new Label(2, 5, "交货时间");
    ws.addCell(lchild);
    lchild = new Label(4, 5, "市 场");
    ws.addCell(lchild);
    lchild = new Label(6, 5, "合约名称");
    ws.addCell(lchild);
    lchild = new Label(8, 5, "成交时间");
    ws.addCell(lchild);
    lchild = new Label(10, 5, "上网时间");
    ws.addCell(lchild);
    lchild = new Label(12, 5, "价 格");
    ws.addCell(lchild);
    lchild = new Label(14, 5, "数 量");
    ws.addCell(lchild);
    lchild = new Label(16, 5, "类 型");
    ws.addCell(lchild);
    int ii = 6;
    
    BigDecimal totalDealprice = new BigDecimal(0);
    Long totalAmount = new Long(0);
    while (its.hasNext()) {
     ii ++;
     TSpotOrder order = (TSpotOrder) its.next();

     String ordercode = order.getOrderCode();
     lchild = new Label(0, ii, ordercode);
     ws.addCell(lchild);

     String tradeTime = order.getLastTradeTime().toString();
     lchild = new Label(2, ii, tradeTime);
     ws.addCell(lchild);

     String exchange = order.getExchange();
     lchild = new Label(4, ii, exchange);
     ws.addCell(lchild);

     String stockname = order.getFuturesStockBase()
       .getStockName();
     lchild = new Label(6, ii, stockname);
     ws.addCell(lchild);

     String dealtime = order.getForMateDealTime();
     lchild = new Label(8, ii, dealtime);
     ws.addCell(lchild);


     lchild = new Label(10, ii, "-");
     ws.addCell(lchild);

     String dealprice = order.getDealPrice().toString();

     lchild = new Label(12, ii, dealprice);
     ws.addCell(lchild);
                   
     totalDealprice = totalDealprice.add(order.getDealPrice());
     
     String amount = String.valueOf(order.getAmount());

     lchild = new Label(14, ii, amount);
     ws.addCell(lchild);
                    
     totalAmount = totalAmount + order.getAmount();
     
     String buy = order.getBuyFormat();

     lchild = new Label(16, ii, buy);
     ws.addCell(lchild);

    }
    lchild = new Label(0, ii + 1, "合计");
    ws.addCell(lchild);
    lchild = new Label(12, ii + 1, totalDealprice.toString());
    ws.addCell(lchild);
    lchild = new Label(14, ii + 1, totalAmount.toString());
    ws.addCell(lchild);
    
    
    int jj = ii + 3;
                int jjj = jj + 2;
    lchild = new Label(4, ii + 2, "订货表",wcfF);
    ws.addCell(lchild);

    lchild = new Label(0, jj, "交货月份");
    ws.addCell(lchild);
    lchild = new Label(2, jj, "市 场");
    ws.addCell(lchild);
    lchild = new Label(4, jj, "合约名称");
    ws.addCell(lchild);
    lchild = new Label(6, jj, "买 / 卖");
    ws.addCell(lchild);
    lchild = new Label(8, jj, "平均价格 ");
    ws.addCell(lchild);
    lchild = new Label(10, jj, "数 量");
    ws.addCell(lchild);
    lchild = new Label(12, jj, "保证金");
    ws.addCell(lchild);
    lchild = new Label(14, jj, "浮 亏");
    ws.addCell(lchild);
    
    BigDecimal totalAvgprice = new BigDecimal(0);
    Long totalAvgamount = new Long(0);
    BigDecimal totalDeposit = new BigDecimal(0);
    BigDecimal totalProloss = new BigDecimal(0);
    
    Iterator _its = sv.getHolds().iterator();
    while (its.hasNext()) {
     jjj ++ ;
     HoldVo4settle hold = (HoldVo4settle) _its.next();

     String month = hold.getDeliverMonth();
     lchild = new Label(0, jjj, month);
     ws.addCell(lchild);

     String market = hold.getMarket();
     lchild = new Label(2, jjj, market);
     ws.addCell(lchild);

     String ordername = hold.getOrderName();
     lchild = new Label(4, jjj, ordername);
     ws.addCell(lchild);

     String buyformat = hold.getBuyFormat();
     lchild = new Label(6, jjj, buyformat);
     ws.addCell(lchild);

     String avgprice = hold.getPrice().toString();
     lchild = new Label(8, jjj, avgprice);
     ws.addCell(lchild);
                   
     totalAvgprice = totalAvgprice.add(hold.getPrice());
     
     String avgamount = hold.getAmount().toString();
     lchild = new Label(10, jjj, avgamount);
     ws.addCell(lchild);
 
     totalAvgamount = totalAvgamount + hold.getAmount();
     
     String deposit = hold.getDeposit().toString();
     lchild = new Label(12, jjj, deposit);
     ws.addCell(lchild);
     
     totalDeposit = totalDeposit.add(hold.getDeposit());

     String proloss = hold.getPro_loss().toString();
     lchild = new Label(14, jjj, proloss);
     ws.addCell(lchild);
     
     totalProloss = totalProloss.add(hold.getPro_loss());

    }

    lchild = new Label(0, jjj , "合计");
    ws.addCell(lchild);
    
    lchild = new Label(8, jjj, totalAvgprice.toString());
    ws.addCell(lchild);
    
    lchild = new Label(10, jjj, totalAvgamount.toString());
    ws.addCell(lchild);
    
    lchild = new Label(12, jjj, totalDeposit.toString());
    ws.addCell(lchild);
    
    lchild = new Label(14, jjj, totalProloss.toString());
    ws.addCell(lchild);
    
    
    lchild = new Label(4, jjj + 2, "资金结算表",wcfF);
    ws.addCell(lchild);
               
    BigDecimal capital = sv.getAddCapital();
    lchild = new Label(0, jjj + 3, "+ 当日存入");
    ws.addCell(lchild);
    lchild = new Label(6, jjj + 3, "- 当日支出 ");
    ws.addCell(lchild);
    lchild = new Label(0, jjj + 4, "+ 当日交易盈亏");
    ws.addCell(lchild);
    lchild = new Label(6, jjj + 4, "- 交易手续费 ");
    ws.addCell(lchild);
    
    if(capital != null){
     lchild = new Label(2, jjj + 3, capital.toString());
     ws.addCell(lchild);
    }

    BigDecimal redcapital = sv.getReduceCapital();
    if(redcapital != null){
     lchild = new Label(8, jjj + 3, redcapital.toString());
     ws.addCell(lchild);
    }

    BigDecimal pro_loss = sv.getPro_loss();
    if(pro_loss != null){
     lchild = new Label(2, jjj + 4, pro_loss.toString());
     ws.addCell(lchild);

    }
    
    BigDecimal fee = sv.getFee();
    if(fee != null){
     lchild = new Label(8, jjj + 4, fee.toString());
     ws.addCell(lchild);
    }
    
               
   }
  } catch (RowsExceededException e) {

   e.printStackTrace();
  } catch (WriteException e) {
   e.printStackTrace();
  }
 }