POI导入导出

常见的用户导入导出：

1.导出：

action层：

//导出用户列表

@Resource
    private UserService userService;
    private List<User> userList;
    private User user;
    private String[] selectedRow;
    
    private File userExcel;
    private String userExcelContentType;
    private String userExcelFileName;

    public void exportExcel(){
        try {
            //1、查找用户列表
            userList = userService.findObjects();
            //2、导出
            HttpServletResponse response = ServletActionContext.getResponse();
            response.setContentType("application/x-execl");
            response.setHeader("Content-Disposition", "attachment;filename=" + new String("用户列表.xls".getBytes(), "ISO-8859-1"));
            ServletOutputStream outputStream = response.getOutputStream();
            userService.exportExcel(userList, outputStream);
            if(outputStream != null){
                outputStream.close();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

service层：

@Override
    public void exportExcel(List<User> userList, ServletOutputStream outputStream) {
        try {
            //1、创建工作簿
            HSSFWorkbook workbook = new HSSFWorkbook();
            //1.1、创建合并单元格对象
            CellRangeAddress cellRangeAddress = new CellRangeAddress(0, 0, 0, 4);//起始行号，结束行号，起始列号，结束列号
            
            //1.2、头标题样式
            HSSFCellStyle style1 = createCellStyle(workbook, (short)16);
            
            //1.3、列标题样式
            HSSFCellStyle style2 = createCellStyle(workbook, (short)13);
            
            //2、创建工作表
            HSSFSheet sheet = workbook.createSheet("用户列表");
            //2.1、加载合并单元格对象
            sheet.addMergedRegion(cellRangeAddress);
            //设置默认列宽
            sheet.setDefaultColumnWidth(25);
            
            //3、创建行
            //3.1、创建头标题行；并且设置头标题
            HSSFRow row1 = sheet.createRow(0);
            HSSFCell cell1 = row1.createCell(0);
            //加载单元格样式
            cell1.setCellStyle(style1);
            cell1.setCellValue("用户列表");
            
            //3.2、创建列标题行；并且设置列标题
            HSSFRow row2 = sheet.createRow(1);
            String[] titles = {"用户名","帐号", "所属部门", "性别", "电子邮箱"};
            for(int i = 0; i < titles.length; i++){
                HSSFCell cell2 = row2.createCell(i);
                //加载单元格样式
                cell2.setCellStyle(style2);
                cell2.setCellValue(titles[i]);
            }
            
            //4、操作单元格；将用户列表写入excel
            if(userList != null){
                for(int j = 0; j < userList.size(); j++){
                    HSSFRow row = sheet.createRow(j+2);
                    HSSFCell cell11 = row.createCell(0);
                    cell11.setCellValue(userList.get(j).getName());
                    HSSFCell cell12 = row.createCell(1);
                    cell12.setCellValue(userList.get(j).getAccount());
                    HSSFCell cell13 = row.createCell(2);
                    cell13.setCellValue(userList.get(j).getDept());
                    HSSFCell cell14 = row.createCell(3);
                    cell14.setCellValue(userList.get(j).isGender()?"男":"女");
                    HSSFCell cell15 = row.createCell(4);
                    cell15.setCellValue(userList.get(j).getEmail());
                }
            }
            //5、输出
            workbook.write(outputStream);
            workbook.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

/**
     * 创建单元格样式
     * @param workbook 工作簿
     * @param fontSize 字体大小
     * @return 单元格样式
     */
    private static HSSFCellStyle createCellStyle(HSSFWorkbook workbook, short fontSize) {
        HSSFCellStyle style = workbook.createCellStyle();
        style.setAlignment(HSSFCellStyle.ALIGN_CENTER);//水平居中
        style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);//垂直居中
        //创建字体
        HSSFFont font = workbook.createFont();
        font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);//加粗字体
        font.setFontHeightInPoints(fontSize);
        //加载字体
        style.setFont(font);
        return style;
    }
    }

2.导入：

action层：

//导入用户列表
    public String importExcel(){
        //1、获取excel文件
        if(userExcel != null){
            //是否是excel
            if(userExcelFileName.matches("^.+\\.(?i)((xls)|(xlsx))$")){
                //2、导入
                userService.importExcel(userExcel, userExcelFileName);
            }
        }
        return "list";
    }

service层：

@Override
    public void importExcel(File userExcel, String userExcelFileName) {
        try {
            FileInputStream fileInputStream = new FileInputStream(userExcel);
            boolean is03Excel = userExcelFileName.matches("^.+\\.(?i)(xls)$");
            //1、读取工作簿
            Workbook workbook = is03Excel ? new HSSFWorkbook(fileInputStream):new XSSFWorkbook(fileInputStream);
            //2、读取工作表
            Sheet sheet = workbook.getSheetAt(0);
            //3、读取行
            if(sheet.getPhysicalNumberOfRows() > 2){
                User user = null;
                for(int k = 2; k < sheet.getPhysicalNumberOfRows(); k++){
                    //4、读取单元格
                    Row row = sheet.getRow(k);
                    user = new User();
                    //用户名
                    Cell cell0 = row.getCell(0);
                    user.setName(cell0.getStringCellValue());
                    //帐号
                    Cell cell1 = row.getCell(1);
                    user.setAccount(cell1.getStringCellValue());
                    //所属部门
                    Cell cell2 = row.getCell(2);
                    user.setDept(cell2.getStringCellValue());
                    //性别
                    Cell cell3 = row.getCell(3);
                    user.setGender(cell3.getStringCellValue().equals("男"));
                    //手机号
                    String mobile = "";
                    Cell cell4 = row.getCell(4);
                    try {
                        mobile = cell4.getStringCellValue();
                    } catch (Exception e) {
                        double dMobile = cell4.getNumericCellValue();
                        mobile = BigDecimal.valueOf(dMobile).toString();
                    }
                    user.setMobile(mobile);
                    
                    //电子邮箱
                    Cell cell5 = row.getCell(5);
                    user.setEmail(cell5.getStringCellValue());
                    //生日
                    Cell cell6 = row.getCell(6);
                    if(cell6.getDateCellValue() != null){
                        user.setBirthday(cell6.getDateCellValue());
                    }
                    //默认用户密码为 123456
                    user.setPassword("123456");
                    //默认用户状态为 有效
                    user.setState(User.USER_STATE_VALID);
                    
                    //5、保存用户
                    save(user);
                }
            }
            workbook.close();
            fileInputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }