spring 下载 Excel（2）

搭建springMVC的环境 
添加Excel的操作包 poi-3.0.1.jar。 

控制器中的方法，这里用的是多动作控制器 

public ModelAndView downCardAccountExcel(HttpServletRequest request,
        HttpServletResponse response, Object command)
        throws ServletRequestBindingException {

    ModelAndView mv = new ModelAndView();
    ExcelCardAccountView mvExcel = new ExcelCardAccountView();

    String queryStr = ReqUtil.getUrl(request);
    Map<String,String> queryMap = ReqUtil.getParamMap(request);

    Map map = new HashMap();
    if(queryMap.size()>1) {//查询
        List<Cardaccount> cardAccounts = cardAccountService.queryCardAccountBy(queryMap,0,maxDownloadCount);
        map.put("records", cardAccounts);
    }

    return new ModelAndView(mvExcel,map);
}

Excel视图类，并将相关的写数据操作放里面，注意要继承AbstractExcelView，让它为Excel视图的子类，并实现 buildExcelDocument方法即可。 

public class ExcelCardAccountView extends AbstractExcelView {

    @Override
    protected void buildExcelDocument(Map map, HSSFWorkbook workbook,
            HttpServletRequest request, HttpServletResponse response) throws Exception {

        int sheetRowNum = 0;    //行控制

        //创建工作表
        HSSFSheet sheet = workbook.createSheet("卡账户查询");


        //取得模型数据
        List list = (List) map.get("records");
        if(list!=null && list.size()>0) {
            //创建标题
            HSSFRow titleRow = sheet.createRow((short) sheetRowNum++);
            HSSFCell titleCell = titleRow.createCell((short) 0);
            titleCell.setCellValue(new HSSFRichTextString("卡账户查询"));

            //创建一个空行
            sheet.createRow(sheetRowNum++);

            //创建数据表头
            String[] titles = { "账户号", "卡号","会员号","商户号","分店号","余额","次数","积分","创建时间" ,"状态"};
            HSSFRow dataTitleRow = sheet.createRow((short) sheetRowNum++);
            for (int i = 0; i < titles.length; i++) {
                HSSFCell cell = dataTitleRow.createCell((short) i);
                cell.setCellValue(new HSSFRichTextString(titles[i]));
            }

            String[] methodArray = { "getAccountId", "getCardId","getMemberId","getMerchantsId","getBranchId","getBalance","getTimes","getIntegral","getGmtCreate" };


            //数据模型转换:创建表格数据
            Iterator<Cardaccount> iter = list.iterator();
            for (int i = sheetRowNum; i < list.size() + sheetRowNum; i++) {
                if (iter.hasNext()) {
                    Cardaccount item = iter.next();
                    HSSFRow dataRow = sheet.createRow((short) (i));
                    ServUtil.writeRowData(item,dataRow,methodArray);    //写入行

                    //其他的数据转换
                    HSSFCell cell_0 = dataRow.createCell((short) methodArray.length);
                    if(item.getStatus()==1) {
                        cell_0.setCellValue(new HSSFRichTextString("正常"));
                    } else {
                        cell_0.setCellValue(new HSSFRichTextString("异常"));
                    }
                }
            }
        } else {//没数据
            //创建提示
            HSSFRow titleRow = sheet.createRow((short) sheetRowNum++);
            HSSFCell titleCell = titleRow.createCell((short) 0);
            titleCell.setCellValue(new HSSFRichTextString("没有数据"));
        }

    }

}

为了避免导出很多列时的重复工作，写了一个方法，将不用转换的数据列设置到行中，方法如下： 

/**
 * 将对象o按methodArray的顺序写入到dataRow的行中，在导出excel中用到
 * @param o             写入的对象
 * @param dataRow       写人的行
 * @param methodArray   拿取o对象的get方法列表 如 String[] paraArray = { "getAccountId", "getCardId"};
 * 效果是，将o的accountId和cardId值设置到dataRow中
 */
public static void writeRowData(Object o, HSSFRow dataRow,String[] methodArray)  {
    Class<?> c = o.getClass();

    for(int i=0;i<methodArray.length;i++) {
        HSSFCell cell = dataRow.createCell((short)i);   //创建一个行
        String methodName = methodArray[i];
        //根据paraArray中的顺序，依次取出o对应方法的值，设置到dataRow中
        Method m = null;
        try {
            m = c.getMethod(methodName);
        } catch (SecurityException e) {
            e.printStackTrace();
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        }
        if(m!=null) {
            try {
                String returnType = m.getReturnType().toString();
                if(returnType.contains("String")) {
                    cell.setCellValue(new HSSFRichTextString((String)m.invoke(o)));
                } else if(returnType.contains("Integer") || returnType.contains("int")) {
                    cell.setCellValue(SimpleFilter.filterNull((Integer)m.invoke(o)));
                } else if(returnType.contains("Date")) {
                    cell.setCellValue(new HSSFRichTextString(SimpleDateUtils.getDateString((Date)m.invoke(o), null)));
                }
            } catch (IllegalArgumentException e) {
                e.printStackTrace();
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            } catch (InvocationTargetException e) {
                e.printStackTrace();
            }
        } else {
            cell.setCellValue(new HSSFRichTextString(""));
        }
    }
}