java下载excel,excel从数据库获取数据

<!-- poi -->
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>3.14</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>3.14</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml-schemas</artifactId>
            <version>3.14</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-scratchpad</artifactId>
            <version>3.14</version>
        </dependency>

controller.java

@RequestMapping("/exportFile")
    public void exportFile(TbCdeShAgentRoadRateInBean form,HttpServletResponse response){

        OutputStream os=null;
        try {
            Workbook wb=wbglService.exportFile(form);
            ByteArrayOutputStream bos=new ByteArrayOutputStream();
            wb.write(bos);
            response.setBufferSize(512);
            response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
            SimpleDateFormat dfs=new SimpleDateFormat("yyyy年mm月dd日HH时mm分ss秒");
            //Date end=dfs.parse();
            String fileName="委办公路"+dfs.format(new Date())+".xlsx";
            response.addHeader("Content-disposition", "attachment; filename=" + new String(fileName.getBytes("UTF-8"), "ISO8859-1"));
            response.addHeader("Content-Length", String.valueOf(bos.toByteArray().length));
            os=response.getOutputStream();
            IOUtils.write(bos.toByteArray(),os);
        } catch (Exception e) {
            e.printStackTrace();
        }finally{
            IOUtils.closeQuietly(os);
        }
    }

service.java

public Workbook exportFile(TbCdeShAgentRoadRateInBean form) throws Exception{
        TbCdeShAgentRoadRateInBean param=getSearchParam(form);
        int count=iwbglDao.getCount(param);
        int pageSize=1000;
        List<TbCdeShAgentRoadRateOutBean> list=null;
        //防止一次查询的数据量过大，导出服务器内存崩了
        int totalPage=(new Double(Math.ceil(count/(pageSize*1.0)))).intValue();
        Workbook wb=new SXSSFWorkbook();
        Sheet sheet=wb.createSheet("委办公路");
        // 设置表格默认列宽度为15个字节
        sheet.setDefaultColumnWidth((short) 15);

     // 生成一个样式
        CellStyle style =wb.createCellStyle(); //workbook.createCellStyle();
        // 设置这些样式
        Font font = wb.createFont();
        font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
        style.setFont(font);
        //标题行
        Row rowTitle=sheet.createRow(0);
        Cell cell=rowTitle.createCell(0);
        cell.setCellStyle(style);
        cell.setCellValue("序号");
        //rowTitle.createCell(1).setCellValue("邮路名称");

        cell=rowTitle.createCell(1);
        cell.setCellStyle(style);
        cell.setCellValue("邮路名称");

        //rowTitle.createCell(2).setCellValue("邮路代码");
        cell=rowTitle.createCell(2);
        cell.setCellStyle(style);
        cell.setCellValue("邮路代码");
        //rowTitle.createCell(3).setCellValue("开行方式");

        cell=rowTitle.createCell(3);
        cell.setCellStyle(style);
        cell.setCellValue("开行方式");
        //rowTitle.createCell(4).setCellValue("代理商");

        cell=rowTitle.createCell(4);
        cell.setCellStyle(style);
        cell.setCellValue("代理商");
        //rowTitle.createCell(5).setCellValue("5T（元/车）");

        cell=rowTitle.createCell(5);
        cell.setCellStyle(style);
        cell.setCellValue("5T（元/车）");
        //rowTitle.createCell(6).setCellValue("8T（元/车）");

        cell=rowTitle.createCell(6);
        cell.setCellStyle(style);
        cell.setCellValue("8T（元/车）");
        //rowTitle.createCell(7).setCellValue("15T（元/车）");

        cell=rowTitle.createCell(7);
        cell.setCellStyle(style);
        cell.setCellValue("15T（元/车）");
        //rowTitle.createCell(8).setCellValue("25T（元/车）");

        cell=rowTitle.createCell(8);
        cell.setCellStyle(style);
        cell.setCellValue("25T（元/车）");
        //rowTitle.createCell(9).setCellValue("起始日期");

        cell=rowTitle.createCell(9);
        cell.setCellStyle(style);
        cell.setCellValue("起始日期");
        //rowTitle.createCell(10).setCellValue("结束日期");

        cell=rowTitle.createCell(10);
        cell.setCellStyle(style);
        cell.setCellValue("结束日期");
        int rowNum=1;
        for(int currentPage=1;currentPage<=totalPage;currentPage++){
            param.setSqlCurrentPage(currentPage);
            param.setSqlPageSize(pageSize);
            param.setDet(1L);
            list=iwbglDao.selectList(param);
            createExcelDataRow(sheet,list,rowNum);
        }
        return wb;
    }
    private int createExcelDataRow(Sheet sheet,List<TbCdeShAgentRoadRateOutBean> list,int rowNum){

        for(TbCdeShAgentRoadRateOutBean b:list){
            Row dataRow = sheet.createRow(rowNum);
            dataRow.createCell(0).setCellValue(b.getRn());
            dataRow.createCell(1).setCellValue(getDataValue(b.getMwayName()));
            dataRow.createCell(2).setCellValue(getDataValue(b.getMwayCode()));
            dataRow.createCell(3).setCellValue(getDataValue(b.getTransType()));
            dataRow.createCell(4).setCellValue(getDataValue(b.getAgentCop()));
            dataRow.createCell(5).setCellValue(getDataValue(b.getFiveT()));
            dataRow.createCell(6).setCellValue(getDataValue(b.getEightT()));
            dataRow.createCell(7).setCellValue(getDataValue(b.getFifteenT()));
            dataRow.createCell(8).setCellValue(getDataValue(b.getTwentyFiveT()));
            dataRow.createCell(9).setCellValue(getDataValue(b.getStartDate()));
            //dataRow.getCell(9).setCellType(Cell.CELL_TYPE_STRING);
            dataRow.createCell(10).setCellValue(getDataValue(b.getEndDate()));
            //dataRow.getCell(10).setCellType(Cell.CELL_TYPE_STRING);
            rowNum++;
        }
        return rowNum;
    }
    private String getDataValue(Object o){
        return o==null?"":o.toString();
    }

html

//导出数据
window.location.href="${path}/wbgl/exportFile?a=b&c=d"