<dependency>
    <groupId>cn.hutool</groupId>
    <artifactId>hutool-all</artifactId>
    <version>4.6.3</version>
</dependency>

   @Test
    public void hutoolCodeTest() throws FileNotFoundException {
        /**、
         * 1、創(chuàng)建一個(gè)驗(yàn)證碼：
         *  驗(yàn)證碼 captcha['k?pt??]
         *  line:線條
         *  參數(shù)說明
         *  width:寬度
         *  height：高度
         *  codeCount:字符數(shù)量
         *  lineCount:干擾線數(shù)量
         */
        LineCaptcha lineCaptcha = CaptchaUtil.createLineCaptcha(200, 40, 4, 4);
        //2.獲得生成的驗(yàn)證碼的真實(shí)碼值
        String code = lineCaptcha.getCode();
        System.out.println(code);
        //3.將驗(yàn)證碼圖片輸出到D盤根目錄下
        lineCaptcha.write(new FileOutputStream("D:/text.png"));
    }?

 <dependency>
      <groupId>org.apache.poi</groupId>
      <artifactId>poi-ooxml</artifactId>
      <version>3.17</version>
    </dependency>
    <dependency>
      <groupId>org.apache.poi</groupId>
      <artifactId>poi-ooxml-schemas</artifactId>
      <version>3.17</version>
    </dependency>

 @Test
    public void HutollDownLoadExcelTest() throws FileNotFoundException {
        //1.創(chuàng)建一個(gè)Excel寫出工具Writer
        ExcelWriter writer = ExcelUtil.getWriter(true);
        //2.模擬List數(shù)據(jù)
        List<Integer> list = new ArrayList<>();
        list.add(1);
        list.add(2);
        list.add(3);
        //3.將list數(shù)據(jù)輸出到excel中
        writer.write(list);
        //4. 將填充數(shù)據(jù)后的excel文件保存在d盤文件中.
        writer.flush(new FileOutputStream("d:/id.xlsx"));
    }

public class User {
    private String id;
    private String name;
    private Integer age;

//1. 創(chuàng)建一個(gè)Excel寫出工具Writer
        ExcelWriter writer = ExcelUtil.getWriter(true);
        //2. 設(shè)置別名
        writer.addHeaderAlias("id","編號");
        writer.addHeaderAlias("name","名字");
        writer.addHeaderAlias("age","年齡");
        writer.addHeaderAlias("birth","生日");
        //3. 先輸出一行標(biāo)題(參數(shù)1是跨列數(shù), 從0開始. 參數(shù)2 是標(biāo)題字符串)
        writer.merge(3,"標(biāo)題");
        //4. 模擬list集合數(shù)據(jù)
        List<User> users = getUsers();
        //5. 將users數(shù)據(jù)輸出到excel文件中.
        writer.write(users,true);// true表示并輸出標(biāo)題。
        //6. 將填充數(shù)據(jù)后的excel文件保存在d盤文件中.
        writer.flush(new FileOutputStream("D:/users.xlsx"));
    }

    private List<User> getUsers(){
        List<User> list = new ArrayList<>();
        list.add(new User("1001","張三",18,new Date()));
        list.add(new User("1002","張三",18,new Date()));
        list.add(new User("1003","張三",18,new Date()));
        list.add(new User("1004","張三",18,new Date()));
        return list;
    }

 @Test
    public void HutollUploadExcelTest() throws FileNotFoundException {
        //1. 創(chuàng)建一個(gè)Excel讀取工具reader
        ExcelReader reader = ExcelUtil.getReader(new FileInputStream("D:/users.xlsx"));
        //2. 設(shè)置讀取的數(shù)據(jù)的別名和封裝的實(shí)體的屬性對應(yīng)關(guān)系.
        reader.addHeaderAlias("編號","id");
        reader.addHeaderAlias("名字","name");
        reader.addHeaderAlias("年齡","age");
        reader.addHeaderAlias("生日","birth");
    /*
        reader讀取excel文件數(shù)據(jù)
        參數(shù)說明
            headerRowIndex: 映射的數(shù)據(jù)標(biāo)題在第幾行, 從0開始算.
            startRowIndex: 實(shí)際讀取的數(shù)據(jù)從第幾行開始, 從0開始算.
            class: 讀取的數(shù)據(jù)封裝成什么類型的對象

     */
        List<User> users = reader.read(1, 2, User.class);
        // 輸出返回的users集合
        System.out.println(users);
        // 輸出users的大小.
        System.out.println(users.size());
    }