用Excel導出數據（一）

按要求從表中找出數據，再以Excel形式下載，操作步驟如下：
Action類

public ActionForward doBillPackDown(BActionContext context)
			throws Exception {
		try{
			HttpServletResponse response = context.getResponse();
			response.setContentType("application/multipart");
			SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmss");
			String TodayDate = sdf.format(new Date());
			String fileName = "Download_BillPack_" + TodayDate + ".xls";
			response.setHeader("Content-Disposition", "filename=" + fileName);
			EPickService service = (EPickService) context.findService("epickService", EPickService.class);
			String[] ids= (String[]) context.getRequest().getParameterValues("ids");
			logger.info("======電子提單明細下載開始=======");
			EPickSearchModel mdl = new EPickSearchModel();
			mdl.setIds(ids);
			HSSFWorkbook workbook = service.downBillPackDetail(mdl);
			workbook.write(response.getOutputStream());
			response.getOutputStream().flush();
			response.getOutputStream().close();
			return null;
        }catch (Exception e) {
			e.printStackTrace();
			logger.error(e);
			if (e.getMessage()!=null && e.getMessage().startsWith("msg:")) {
				context.getRequest().setAttribute("msg",
						e.getMessage().substring(4));
			} else {
				context.getRequest().setAttribute("error", e);
			}
			return context.findForward("fail");
		}
	}

ServiceImpl類：

public HSSFWorkbook downBillPackDetail(EPickSearchModel mdl)
			throws Exception {
		return epickDao.downBillPackDetail(mdl);
	}

DaoImpl類：

public HSSFWorkbook downBillPackDetail(EPickSearchModel mdl)
			throws Exception {
		String[] billIds = mdl.getIds();
		StringBuffer hql = new StringBuffer();
		hql.append("select t.billId,t.orderNum,t.shopsign,t.specDesc,t.packId,t.netWeight,t.grossWeight" +
				" from TplBillPack t where t.billNum in (");
		int idSize = billIds.length;
		for (int i=0; i<idSize-1;i++ ){
			hql.append(""+new String(billIds[i]) + ",");
		}
		hql.append(""+new String(billIds[idSize-1]) + ")");
		hql.append(" order by t.billId, t.orderNum");
		List billPackList = this.queryByHql(hql.toString());
		//實例化一個hssfworkbook對象
		HSSFWorkbook wb = new HSSFWorkbook();
		downBillPackDetailHelp(wb,billPackList);
		return wb;
	}

public void downBillPackDetailHelp(HSSFWorkbook wb, List billPackList)throws Exception{
		try{
			Object [] objHead=getHeadFromBillPack();
			LinkedList headList=(LinkedList)objHead[0];

			//創建一個sheet
			HSSFSheet sheet = wb.createSheet("contract_list");

			//設置單元格的樣式
			HSSFCellStyle cellStyle0 = wb.createCellStyle();
	        cellStyle0.setAlignment(HSSFCellStyle.ALIGN_CENTER);
	        cellStyle0.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);

			short rownum = 0; 
			//創建第一行
			HSSFRow srow = sheet.createRow(rownum);		     
//			HSSFCell cellHead = null;
//			srow = sheet.createRow( (short) rownum);
//			
//	        srow.setHeightInPoints(30);//設置高度  
//	        cellHead = srow.createCell((short) 0);
//	        cellHead.setEncoding(HSSFCell.ENCODING_UTF_16);//設置編碼
//	        cellHead.setCellValue("電子提單明細"); //單元格內容
//			cellHead.setCellStyle(cellStyle0);  //單元格樣式
//			
//			srow = sheet.createRow( (short) 1);
//			//srow.setHeight( (short) 300); 
//			rownum++;
//			srow = sheet.createRow(rownum);

			for (int i = 0; i < headList.size(); i++){
				HSSFCell cell = srow.createCell((short) (i));      
				cell.setEncoding(HSSFCell.ENCODING_UTF_16);
				cell.setCellValue(headList.get(i).toString());
			}

			for(Iterator it = billPackList.iterator();it.hasNext();) {
				Object[] obj = (Object[])it.next();
				rownum++;
				srow = sheet.createRow(rownum);
				for (int j = 0; j < headList.size(); j++) {
					HSSFCell cell=srow.createCell((short)j);
					if(obj[j]==null)
						cell.setCellValue("");
					else
						cell.setCellValue(obj[j].toString());
				}
			}
		}catch(Exception e){
			e.printStackTrace();
		}
	}

	/**
	 * 獲取Excel第一行標題
	 * @return
	 */
	private Object []getHeadFromBillPack(){
		List head =new LinkedList();
		head.add("提單號");
		head.add("合同號");
		head.add("牌號");
		head.add("規格");
		head.add("捆包號");
		head.add("淨重");
		head.add("毛重");

		Object [] obj=new Object[1];
		obj[0]=head;
		return obj;
	}

jsp頁面中的js代碼：

function billPackDown(){
		var ids = document.getElementsByName('checkbox');
		var ids_java = new Array();
		var count = 0;
		var msg = "";

		if(ids.length == 0)
		{
			alert("現在沒有記錄信息，不能下載!");
			return;
		}

		for(i=0; i < ids.length; i++)
		{
			if(ids[i].checked)
			{
				count ++;
				ids_java.push(ids[i].value);
			}
		}

		if(count < 1 || count > 5)
		{
			alert("電子提單明細下載需至少選擇1條且不多於5條的提單記錄!");
			return;
		}

		if (msg != ""){
		    msg += "請用戶重新選擇！";
		    alert(msg);
		    return;
		} 

		window.open('../ePick/ePickPrintManage.do?method=billPackDown&ids='+ids_java,'','width=800,height=500,top=100,left=150,scrollbars=yes,resizable=yes');
	}