java获取验证码

	@GetMapping("/captcha")
	@ApiOperation(value = "获取验证码")
	public R<Kv> captcha() {
		SpecCaptcha specCaptcha = new SpecCaptcha(130, 48, 5);
		String verCode = specCaptcha.text().toLowerCase();
		String key = UUID.randomUUID().toString();
		// 存入redis并设置过期时间为30分钟
		redisUtil.set(CacheNames.CAPTCHA_KEY + key, verCode, 30L, TimeUnit.MINUTES);
		// 将key和base64返回给前端
		return R.data(Kv.init().set("key", key).set("image", specCaptcha.toBase64()));
	}

<dependency>
    <groupId>com.github.whvcse</groupId>
    <artifactId>easy-captcha</artifactId>
    <version>1.6.2</version>
</dependency>