jfinal-captcha 產生圖形驗證碼__java

maven 引用 ${jfinal-captcha.version}替換為相應的版本如:0.1<dependency>  <groupId>cn.dreampie</groupId>  <artifactId>jfinal-captcha</artifactId>  <version>${jfinal-captcha.version}</version></dependency>

 /**     * 擷取驗證碼     */    @ResponseBody    @RequestMapping(value = "captcha", produces = arrayOf("image/png"))    fun getCaptcha(@RequestParam("token") token: String): ByteArray {        val outImg = ByteArrayOutputStream()        val captcha = captchaService.getCaptcha()        val image = captcha.image        val captchaCode = captcha.challenge        try {            ImageIO.write(image, "png", outImg)            return outImg.toByteArray();        } catch (e: Exception) {            logger.error("驗證碼出錯輸出", e);            return ByteArray(0)        } finally {            try {                outImg.close()            } catch (e: IOException) {                logger.warn("關閉io時出錯", e)            }        }    }