三分钟带你掌握Java开发图片验证码功能方法

getCode() {
      getCodeImg().then(res => {
        this.codeUrl = "data:image/gif;base64," + res.img;
        this.loginForm.uuid = res.uuid;
      });
    },

/**

●  生成验证码
*/
@GetMapping("/captchaImage")
public AjaxResult getCode(HttpServletResponse response) throws IOException{
    // 生成验证码信息
    String uuid = IdUtils.simpleUUID();
    String verifyKey = Constants.CAPTCHA_CODE_KEY + uuid;
    String capStr = null;
    BufferedImage image = null;
    // 生成验证码 可以配置多种类型的验证码
    if ("math".equals(captchaType)){
        capStr = captchaProducerMath.createText();
        image = captchaProducerMath.createImage(capText);
    }
    else if ("char".equals(captchaType)){
        capStr = captchaProducer.createText();
        image = captchaProducer.createImage(capStr);
    }
    // 存入redis
    redisCache.setCacheObject(verifyKey, code, Constants.CAPTCHA_EXPIRATION, TimeUnit.MINUTES);
    // 转换流信息写出
    FastByteArrayOutputStream os = new FastByteArrayOutputStream();
    try{
        ImageIO.write(image, "jpg", os);
    }
    catch (IOException e){
    	return AjaxResult.error(e.getMessage());
    }
    AjaxResult ajax = AjaxResult.success();
    ajax.put("uuid", uuid);
    // 转码base64
    ajax.put("img", Base64.encode(os.toByteArray()));
    return ajax;
} 

password: "admin123"
username: "admin"
uuid: "66ae1f227bf245a8b6ec2e6c00fb6189"
code: "1234"

@PostMapping("/login")
public AjaxResult login(@RequestBody  LoginBody loginBody) {
  AjaxResult ajax = AjaxResult.success();
  String token = loginService.login(loginBody.getUsername(), loginBody.getPassword(), loginBody.getCode(),
  loginBody.getUuid());
  ajax.put(Constants.TOKEN, token);
  return ajax;
}

/**
* 登录验证
*
* @param  username 用户名 
* @param  password 密码 
* @param  code 验证码 
* @param  uuid 唯一标识 
* @return  结果 
*/
public String login(String username, String password, String code, String uuid)
{
  String verifyKey = Constants.CAPTCHA_CODE_KEY + uuid;
  // 根据UUID 去redis取出正确的验证码======================================================
  String captcha = redisCache.getCacheObject(verifyKey);
  redisCache.deleteObject(verifyKey);
  // 验证redis的验证码和用户输入的验证码是否相等。
  // 验证账号密码
  // 验证错误就抛出异常
  
  // 生成token
  return tokenService.createToken(loginUser);
}