java通过POI解析Excel表格内容

为了使用SpringMVC读取参数使用MultipartFile接收参数，但MultipartFile与File不同，传参时经常会出现错误，可以通过getInputStream讲其转换为IO流做进一步处理。

    public ModelAndView readExcel(MultipartFile aaa){

        ModelAndView mav=new ModelAndView();
        BufferedInputStream bf=null;
        try {
            bf=new BufferedInputStream(aaa.getInputStream());
        } catch (Exception e) {
            e.printStackTrace();
        }

        XSSFWorkbook workbook=null;
        try {
            workbook=new XSSFWorkbook(bf);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        System.out.println("___workbook__"+workbook);
        XSSFSheet sheet = workbook.getSheetAt(0);
        for (int rowIndex = 0; rowIndex <= sheet.getLastRowNum(); rowIndex++) {  
            XSSFRow row = sheet.getRow(rowIndex);  
            if (row == null) {  
                continue;  
            }  
            XSSFCell cell = null;  
            for (short columnIndex = 0; columnIndex <= row.getLastCellNum(); columnIndex++) {  
                String value = "";  
                cell = row.getCell(columnIndex);  
                if (cell != null) {  
                    // 注意：一定要设成这个，否则可能会出现乱码  
                    // cell.setEncoding(HSSFCell.ENCODING_UTF_16);  
                    switch (cell.getCellType()) {  
                    case XSSFCell.CELL_TYPE_STRING:  
                        value = cell.getStringCellValue();  
                        break;  
                    case XSSFCell.CELL_TYPE_NUMERIC:  
                        if (HSSFDateUtil.isCellDateFormatted(cell)) {  
                            Date date = cell.getDateCellValue();  
                            if (date != null) {  
                                value = new SimpleDateFormat("yyyy-MM-dd")  
                                        .format(date);  
                            } else {  
                                value = "";  
                            }  
                        } else {  
                            value = new DecimalFormat("0").format(cell  
                                    .getNumericCellValue());  
                        }  
                        break;  
                    case XSSFCell.CELL_TYPE_FORMULA:  
                        // 导入时如果为公式生成的数据则无值  
                        if (!cell.getStringCellValue().equals("")) {  
                            value = cell.getStringCellValue();  
                        } else {  
                            value = cell.getNumericCellValue() + "";  
                        }  
                        break;  
                    case XSSFCell.CELL_TYPE_BLANK:  
                        break;  
                    case XSSFCell.CELL_TYPE_ERROR:  
                        value = "";  
                        break;  
                    case XSSFCell.CELL_TYPE_BOOLEAN:  
                        value = (cell.getBooleanCellValue() == true ? "Y" : "N");  
                        break;  
                    default:  
                        value = "";  
                    }  
                }  
                if (columnIndex == 0 && value.trim().equals("")) {  
                    break;  
                }  
                //excel表格中字段顺序为:用户名,密码,电话和地址,为方便起见假设字段一一对应  
                if (columnIndex == 0) {  
                    String n = value;
                    System.out.print(n+" ");
                } else if (columnIndex == 1) {  
                    String v = value;
                    System.out.print(v+" ");
                } else if (columnIndex == 2) {  
                    String v = value;
                    System.out.print(v+" ");
                } else if (columnIndex == 3) {  
                    String v = value;
                    System.out.println(v+" ");
                } 
            }  
        }
        mav.setViewName("wm/wmTcDaily/edit");
        return mav;
    }

通过测试可以把excel文件中的内容输入至控制台，后续操作可将取得的字段封入实体类，进一步存入List，最终存入数据库

导出excel表文件：

@RequestMapping("/download")
    public ModelAndView transferExcel(HttpServletResponse response){
        ModelAndView mav=new ModelAndView();
        //创建HSSFWorkbook对象(excel的文档对象)  
        HSSFWorkbook wkb = new HSSFWorkbook();  
        //建立新的sheet对象（excel的表单）  
        HSSFSheet sheet=wkb.createSheet("成绩表");  
        //在sheet里创建第一行，参数为行索引(excel的行)，可以是0～65535之间的任何一个  
        HSSFRow row1=sheet.createRow(0);  
        //创建单元格（excel的单元格，参数为列索引，可以是0～255之间的任何一个  
        HSSFCell cell=row1.createCell(0);  
        //设置单元格内容  
        cell.setCellValue("学员考试成绩一览表");  
        //合并单元格CellRangeAddress构造参数依次表示起始行，截至行，起始列， 截至列  
        sheet.addMergedRegion(new CellRangeAddress(0,0,0,3));  
        //在sheet里创建第二行  
        HSSFRow row2=sheet.createRow(1);      
        //创建单元格并设置单元格内容  
        row2.createCell(0).setCellValue("姓名");  
        row2.createCell(1).setCellValue("班级");      
        row2.createCell(2).setCellValue("笔试成绩");  
        row2.createCell(3).setCellValue("机试成绩");      
        //在sheet里创建第三行  
        HSSFRow row3=sheet.createRow(2);  
        row3.createCell(0).setCellValue("李明");  
        row3.createCell(1).setCellValue("As178");  
        row3.createCell(2).setCellValue(87);      
        row3.createCell(3).setCellValue(78);      
        //输出Excel文件  
        OutputStream output;
        try {
            output = response.getOutputStream();
            response.reset();  
            response.setHeader("Content-disposition", "attachment; filename=details.xls");  
            response.setContentType("application/msexcel");          
            wkb.write(output);  
            output.close();  
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        mav.setViewName("wm/wmTcDaily/edit");
        return mav;
    }