Apache POI导入导出Excel

一、添加依赖

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>4.1.2</version>
</dependency>

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>4.1.2</version>
</dependency>

<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.18.22</version>
</dependency>

二、工具类

2.1、日期工具类

public class DateUtil {
    
    
    /**
     * @Author: xuxiansheng
     * @Description: 获取当前日期 年月日
     * @Date: 2021/12/23 11:07
     * @Parms: [java.util.Date]
     * @ReturnType: java.lang.String
     */
    public static String getDate(Date date) {
    
    
        SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
        String format = sdf.format(date);
        return format;
    }

    /**
     * @Author: xuxiansheng
     * @Description: 获取当前日期 年月日时分秒
     * @Date: 2021/12/23 11:08
     * @Parms: [java.util.Date]
     * @ReturnType: java.lang.String
     */
    public static String getDateTime(Date date) {
    
    
        SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmss");
        String format = sdf.format(date);
        return format;
    }
}

2.2、Excel工具类

public class ExportExcelUtil {
    
    
    /**
     * @Author: xuxiansheng
     * @Description:
     * @Date: 2021/12/21 15:52
     * @Parms: [org.apache.poi.xssf.usermodel.XSSFWorkbook, org.apache.poi.xssf.usermodel.XSSFSheet, java.lang.String, int]
     * @ReturnType: void
     */
    public static void createHeadTittle(XSSFWorkbook wb, XSSFSheet sheet, String headString, int col) {
    
    
        //创建Excel工作表的行
        XSSFRow row = sheet.createRow(0);
        //创建Excel工作表指定行的单元格
        XSSFCell cell = row.createCell(0);
        //设置高度
        row.setHeight((short) 800);
        //定义单元格为字符串类型
        cell.setCellType(CellType.STRING);
        cell.setCellValue(headString);
        //指定标题合并区域
        sheet.addMergedRegion(new CellRangeAddress(0, 0, 0, col));

        //定义单元格格式，添加单元格表样式，并添加到工作簿
        XSSFCellStyle cellStyle = wb.createCellStyle();
        //指定单元格居中对齐
        cellStyle.setAlignment(HorizontalAlignment.CENTER);
        //指定单元格垂直居中个对齐
        cellStyle.setVerticalAlignment(VerticalAlignment.CENTER);
        //指定单元格自动换行
        cellStyle.setWrapText(true);

        //单元格合并后设置标题边框不生效
        //cellStyle.setBorderTop(BorderStyle.MEDIUM);
        //cellStyle.setBorderBottom(BorderStyle.MEDIUM);
        //cellStyle.setBorderLeft(BorderStyle.MEDIUM);
        //cellStyle.setBorderRight(BorderStyle.MEDIUM);

        //设置单元格字体
        XSSFFont font = wb.createFont();
        font.setBold(true);
        font.setFontName("微软雅黑");
        //字体大小
        font.setFontHeightInPoints((short) 18);

        cellStyle.setFont(font);
        cell.setCellStyle(cellStyle);
    }

    /**
     * @Author: xuxiansheng
     * @Description: 创建header
     * @Date: 2021/12/21 16:00
     * @Parms: [org.apache.poi.xssf.usermodel.XSSFWorkbook, org.apache.poi.xssf.usermodel.XSSFSheet, java.lang.String[], int[]]
     * @ReturnType: void
     */
    public static void createThead(XSSFWorkbook wb, XSSFSheet sheet, String[] thead, int[] sheetWidth) {
    
    
        XSSFRow row = sheet.createRow(1);
        row.setHeight((short) 600);
        //定义单元格格式，添加单元格表样式，并添加到工作簿
        XSSFCellStyle cellStyle = wb.createCellStyle();
        cellStyle.setAlignment(HorizontalAlignment.CENTER);
        cellStyle.setVerticalAlignment(VerticalAlignment.CENTER);
        cellStyle.setWrapText(true);
        //设置边框类型
        cellStyle.setBorderTop(BorderStyle.THIN);
        cellStyle.setBorderBottom(BorderStyle.MEDIUM);
        cellStyle.setBorderLeft(BorderStyle.THIN);
        cellStyle.setBorderRight(BorderStyle.THIN);

        //设置右边框颜色
        //cellStyle.setRightBorderColor(IndexedColors.RED.index);

        //设置单元格字体
        XSSFFont font = wb.createFont();
        font.setBold(true);
        font.setFontName("宋体");
        font.setFontHeightInPoints((short) 15);
        cellStyle.setFont(font);

        //循环设置表头内容
        for (int i = 0; i < thead.length; i++) {
    
    
            XSSFCell cell1 = row.createCell(i);
            cell1.setCellType(CellType.STRING);
            cell1.setCellValue(thead[i]);
            cell1.setCellStyle(cellStyle);
        }
        //循环设置每一列宽度
        for (int i = 0; i < sheetWidth.length; i++) {
    
    
            sheet.setColumnWidth(i, sheetWidth[i]);
        }
    }


    /**
     * @Author: xuxiansheng
     * @Description: 将数据插入到Excel中
     * @Date: 2021/12/21 16:14
     * @Parms: [org.apache.poi.xssf.usermodel.XSSFWorkbook, org.apache.poi.xssf.usermodel.XSSFSheet, java.util.List<java.util.LinkedHashMap<java.lang.String,java.lang.String>>]
     * @ReturnType: void
     */
    public static void createTable(XSSFWorkbook wb, XSSFSheet sheet, List<LinkedHashMap<String, String>> result) {
    
    
        //定义单元格格式，添加单元格表样式，并添加到工作薄
        XSSFCellStyle cellStyle = wb.createCellStyle();
        cellStyle.setWrapText(true);

        //单元格字体
        XSSFFont font = wb.createFont();
        font.setFontName("宋体");
        font.setFontHeightInPoints((short) 10);
        cellStyle.setFont(font);
        //居中
        cellStyle.setAlignment(HorizontalAlignment.CENTER);
        //设置边框类型  不添加上边框 因为上一行数据已经添加过了
        //cellStyle.setBorderTop(BorderStyle.THIN);
        cellStyle.setBorderBottom(BorderStyle.MEDIUM);
        cellStyle.setBorderLeft(BorderStyle.THIN);
        cellStyle.setBorderRight(BorderStyle.THIN);
        //循环插入数据
        for (int i = 0; i < result.size(); i++) {
    
    
            XSSFRow row = sheet.createRow(i + 2);
            //设置高度
            row.setHeight((short) 400);
            XSSFCell cell = null;
            int j = 0;
            for (String key : (result.get(i).keySet())) {
    
    
                cell = row.createCell(j);
                cell.setCellStyle(cellStyle);
                String value = result.get(i).get(key);
                cell.setCellValue(value);
                j++;
            }
        }
    }
}

三、实体类

@Data
@NoArgsConstructor
@AllArgsConstructor
public class User {
    
    
    //编号
    private int id;
    //姓名
    private String userName;
    //年龄
    private int age;
    //性别
    private String sex;
    //地址
    private String address;
}

四、导出测试

public class ExcelExportTest {
    
    
    //文件存放路径
    private final static String PATH = "D://opt//home//";

    //sheet名
    private final static String SHEET_NAME = "用户数据明细";

    //标题
    private final static String TITLE_NAME = "用户数据明细导出数据";

    //head
    private final static String[] THEAD = {
    
    "编号", "姓名", "年龄", "性别", "地址"};

    //定义每一列的宽度
    private final static int[] SHEET_WIDTH = {
    
    3000, 3000, 3000, 3000, 3000};

    //列数总共5列  0-4
    private final static int COL_COUNT = 4;

    public static void main(String[] args) {
    
    
        //1.创建Excel文档对象
        XSSFWorkbook wb = new XSSFWorkbook();
        //2.创建工作表
        XSSFSheet sheet = wb.createSheet(SHEET_NAME);
        //3.创建标题并合并单元格
        ExportExcelUtil.createHeadTittle(wb, sheet, TITLE_NAME, COL_COUNT);
        //4.创建head并设置单元格格式
        ExportExcelUtil.createThead(wb, sheet, THEAD, SHEET_WIDTH);
        //5.模拟数据并将数据转换格式
        List<User> list = new ArrayList<>();
        list.add(new User(1, "Agnes", 19, "女", "北京"));
        list.add(new User(2, "Darlene", 21, "男", "上海"));
        list.add(new User(3, "Heloise", 23, "女", "杭州"));
        list.add(new User(4, "Sally", 18, "女", "深圳"));
        list.add(new User(5, "Sherry", 22, "男", "杭州"));
        list.add(new User(6, "Joyce", 23, "女", "苏州"));
        list.add(new User(7, "Meredith", 34, "男", "郑州"));
        list.add(new User(8, "Nina", 21, "女", "西安"));
        list.add(new User(9, "Bonnie", 19, "男", "成都"));
        list.add(new User(10, "Gill", 22, "女", "广州"));
        //转换格式
        List<LinkedHashMap<String, String>> result = new ArrayList<>();
        for (User user : list) {
    
    
            LinkedHashMap<String, String> map = new LinkedHashMap<>();
            map.put("id", String.valueOf(user.getId()));
            map.put("name", user.getUserName());
            map.put("age", String.valueOf(user.getAge()));
            map.put("sex", user.getSex());
            map.put("address", user.getAddress());
            result.add(map);
        }
        //6.将数据添加到Excel中
        ExportExcelUtil.createTable(wb, sheet, result);

        //7.生成文件名 yyyyMMdd/yyyyMMddHHmmss + _随机数 + _user_eport.xlsx
        Date date = new Date();
        String dateDir = DateUtil.getDate(date);
        String dateTimeDir = DateUtil.getDateTime(date);
        Random random = new SecureRandom();
        int randomNum = random.nextInt(10000);
        String url = "";
        url = PATH + dateDir + "/" + dateTimeDir + "_" + randomNum + "_user_eport.xlsx";

        //8将数据写入到Excel中
        FileOutputStream fos;
        try {
    
    
            File file = new File(url);
            File fileParent = file.getParentFile();
            if (!fileParent.exists()) {
    
    
                fileParent.mkdirs();
            }
            file.createNewFile();

            fos = new FileOutputStream(file);
            wb.write(fos);
            fos.close();
            System.out.println("导出excel成功");
        } catch (FileNotFoundException ex) {
    
    
            ex.printStackTrace();
        } catch (IOException ex) {
    
    
            ex.printStackTrace();
        }
    }
}

文件存放路径和文件名称

Excel导出内容展示

五、导入测试

public class ExcelImportTest {
    
    
    //文件存放路径
    private final static String PATH = "D:/opt/home/20211224/20211224090314_7362_user_eport.xlsx";

    public static void main(String[] args) {
    
    
        try {
    
    
            //1.创建Workbook
            Workbook workbook = new XSSFWorkbook(new FileInputStream(PATH));

            //2.获取Sheet表
            //2.1按索引获取
            //Sheet sheet = workbook.getSheetAt(0);
            //2.2按sheef名称获取
            Sheet sheet = workbook.getSheet("用户数据明细");

            //3.获取行数(0 - 行数-1)
            int lastRowNum = sheet.getLastRowNum();
            //System.out.println("lastRowNum = " + lastRowNum);

            //存储所有对象的集合
            List<User> userList = new ArrayList<>();

            //4.遍历行
            //记得除去标题和head
            for (int i = 2; i <= lastRowNum; i++) {
    
    
                //4.1获取当前行
                Row row = sheet.getRow(i);
                //4.2判断是否为空行
                if (row == null) {
    
    
                    System.out.println("一次");
                    continue;
                }

                //4.3遍历每一行的数据
                //获取最后一列 (0 - 列数-1)
                int lastCellNum = row.getLastCellNum();
                for (int j = 0; j < lastCellNum; j++) {
    
    
                    Cell cell = row.getCell(j);
                    String value = cell.getStringCellValue();
                    System.out.print(value + "\t");
                }
                System.out.println();

                //4.4将数据读取到user实体中
                User user = new User();
                //校验单元格的值,这里省略,根据实际业务修改
                user.setId(Integer.parseInt(row.getCell(0).getStringCellValue()));
                user.setUserName(row.getCell(1).getStringCellValue());
                user.setAge(Integer.parseInt(row.getCell(2).getStringCellValue()));
                user.setSex(row.getCell(3).getStringCellValue());
                user.setAddress(row.getCell(4).getStringCellValue());
                userList.add(user);
            }

            //5.遍历userList
            for (User user : userList) {
    
    
                System.out.println(user);
            }
        } catch (IOException e) {
    
    
            e.printStackTrace();
        }
    }
}