java操作Excel之POI（4）利用POI实现数据的批量导出

后台导出方法：

/**
*    后台导出方法
*    利用POI实现数据的批量导出
*/
public String export() throws Exception{
    Connection con = null;
    try{
        con = dbUtil.getCon();
        Workbook wb = new HSSFWorkbook();
        String headers[] = {"编号", "姓名", "电话", "Email", "QQ"};
        ResultSet rs = userDao.userList(con, null);
        ExcelUtil.fillExcelData(rs, wb, headers);

        //把wb以流的形式输出
        ResponseUtil.export(ServletActionContext.getResponse(), wb, "导出Excel.xls");
    }catch(Exception e){
        e.printStackTrace();
    }finally{
        try{
            dbUtil.closeCon(con);
            dbUtil.closeRs(rs);
        }catch(Exception e){
            e.printStackTrace();
        }
    }

    return null;
}

处理excel的Util：

/**
*    处理Excel的util
*/
public class ExcelUtil{

    public static void fillExcelData(ResultSet rs, Workbook wb, String[] headers) throws Exception{
        int rowIndex = 0;
        Sheet sheet = wb.createSheet();
        Row row = sheet.createRow(rowIndex++);
        for(int i=0; i<headers.length; i++){
            row.createCell(i).setCellValue(headers[i]);
        }

        //这里假设的是头的列数和数据的列数是一样的
        while(rs.next()){
            row = sheet.createRow(rowIndex++);
            for(int i=0; i<headers.length; i++){
                row.createCell(i).setCellValue(rs.getObject(i+1).toString());
            }
        }
    }
}

ResponseUtil以流的形式导出Workbook:

/**
*    ResponseUtil相应util
*/
public class ResponseUtil{
    public static void write(HttpServletResponse response, Object o) throws Exception{
        response.setContentType("text/html;charset=utf-8");
        PrintWriter pw = response.getWriter();
        pw.print(o.toString());
        pw.flush();
        pw.close();
    }

    /**
    *导出Excel
    * fileName: 导出的文件名
    */
    public static void export(HttpServletResponse response, Workbook wb, String fileName) throws Exception{
        response.setHeader("Content-Disposition", "attachment;filename="
            +new String(fileName.getBytes("utf-8"), "iso8859-1"));
        response.setContentType("application/ynd.ms-excel;charset=UTF-8");
        OutputStream out = response.getOutputStream();
        wb.write(out);
        out.flush();
        out.close();
    }
}

导出的Excel: