Java Hutool工具实现验证码生成及Excel文件的导入和导出

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

   @Test
    public void hutoolCodeTest() throws FileNotFoundException {
        /**、
         * 1、创建一个验证码：
         *  验证码 captcha['kæptʃə]
         *  line:线条
         *  参数说明
         *  width:宽度
         *  height：高度
         *  codeCount:字符数量
         *  lineCount:干扰线数量
         */
        LineCaptcha lineCaptcha = CaptchaUtil.createLineCaptcha(200, 40, 4, 4);
        //2.获得生成的验证码的真实码值
        String code = lineCaptcha.getCode();
        System.out.println(code);
        //3.将验证码图片输出到D盘根目录下
        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.创建一个Excel写出工具Writer
        ExcelWriter writer = ExcelUtil.getWriter(true);
        //2.模拟List数据
        List<Integer> list = new ArrayList<>();
        list.add(1);
        list.add(2);
        list.add(3);
        //3.将list数据输出到excel中
        writer.write(list);
        //4. 将填充数据后的excel文件保存在d盘文件中.
        writer.flush(new FileOutputStream("d:/id.xlsx"));
    }

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

//1. 创建一个Excel写出工具Writer
        ExcelWriter writer = ExcelUtil.getWriter(true);
        //2. 设置别名
        writer.addHeaderAlias("id","编号");
        writer.addHeaderAlias("name","名字");
        writer.addHeaderAlias("age","年龄");
        writer.addHeaderAlias("birth","生日");
        //3. 先输出一行标题(参数1是跨列数, 从0开始. 参数2 是标题字符串)
        writer.merge(3,"标题");
        //4. 模拟list集合数据
        List<User> users = getUsers();
        //5. 将users数据输出到excel文件中.
        writer.write(users,true);// true表示并输出标题。
        //6. 将填充数据后的excel文件保存在d盘文件中.
        writer.flush(new FileOutputStream("D:/users.xlsx"));
    }

    private List<User> getUsers(){
        List<User> list = new ArrayList<>();
        list.add(new User("1001","张三",18,new Date()));
        list.add(new User("1002","张三",18,new Date()));
        list.add(new User("1003","张三",18,new Date()));
        list.add(new User("1004","张三",18,new Date()));
        return list;
    }

 @Test
    public void HutollUploadExcelTest() throws FileNotFoundException {
        //1. 创建一个Excel读取工具reader
        ExcelReader reader = ExcelUtil.getReader(new FileInputStream("D:/users.xlsx"));
        //2. 设置读取的数据的别名和封装的实体的属性对应关系.
        reader.addHeaderAlias("编号","id");
        reader.addHeaderAlias("名字","name");
        reader.addHeaderAlias("年龄","age");
        reader.addHeaderAlias("生日","birth");
    /*
        reader读取excel文件数据
        参数说明
            headerRowIndex: 映射的数据标题在第几行, 从0开始算.
            startRowIndex: 实际读取的数据从第几行开始, 从0开始算.
            class: 读取的数据封装成什么类型的对象

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