Hutool验证码的官方文档

https://www.hutool.cn/docs/#/captcha/%E6%A6%82%E8%BF%B0

引入Hutool的依赖包

<dependency>
   <groupId>cn.hutool</groupId>
    <artifactId>hutool-all</artifactId>
    <version>5.2.3</version>
</dependency>

编写controller接口

@RestController
@RequestMapping("/user")
public class LoginController {
    private Logger logger = LoggerFactory.getLogger(LoginController.class);
    //验证码工具类
    private LineCaptcha lineCaptcha;

 

    /**
     * 用户登录的方法
     * @param loginUser
     * @return
     */
    @ApiOperation(value = "用户登录",notes = "用户登录成功之后，返回给前端一个token")
    @PostMapping("/login")
    public CommonResult userLogin(@RequestBody LoginUser loginUser){
        System.out.println("验证码--"+lineCaptcha.getCode());


        if (loginUser.getCode().equals(lineCaptcha.getCode())){
        //省略校验用户输入的其他信息....
            return CommonResult.ok().message("登录成功");
        }
            return CommonResult.error().message("登录失败");

    }


	//用来生成验证码的接口，HttpServletResponse 用于将生成的验证码响应到页面展示
    @RequestMapping("/getCode")
    public  void getCode(HttpServletResponse response){
        //HuTool定义图形验证码的长和宽,验证码的位数，干扰线的条数
         lineCaptcha = CaptchaUtil.createLineCaptcha(116, 36,4,10);
        System.out.println(lineCaptcha.getCode()+"验证码的值");
        response.setContentType("image/jpeg");
        response.setHeader("Pragma", "No-cache");
        try {
            ServletOutputStream outputStream = response.getOutputStream();
            lineCaptcha.write(outputStream);
            outputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }


//获取验证码的方式2
/**
     * 生成验证码
     * @param response
     */
    @RequestMapping("/getCode")
    public void getCode(HttpServletResponse response) {
        // 随机生成 4 位验证码
        RandomGenerator randomGenerator = new RandomGenerator("0123456789", 4);
        // 定义图片的显示大小
        lineCaptcha = CaptchaUtil.createLineCaptcha(100, 30);
        response.setContentType("image/jpeg");
        response.setHeader("Pragma", "No-cache");
        try {
            // 调用父类的 setGenerator() 方法，设置验证码的类型
            lineCaptcha.setGenerator(randomGenerator);
            // 输出到页面
            lineCaptcha.write(response.getOutputStream());
            // 打印日志
            logger.info("生成的验证码:{}", lineCaptcha.getCode());
            // 关闭流
            response.getOutputStream().close();
        } catch (IOException e) {
            e.printStackTrace();
        }