官网中有这么一段: If you need to save this new SecretKey, you can Base64 (or Base64URL) encode it: `String secretString = Encoders.BASE64.encode(key.getEncoded());` 链接:[https://github.com/jwtk/jjwt?tab=readme-ov-file#creating-safe-keys](https://link.segmentfault.com/?enc=e8Izh6UeFr1B4XDKXBwCTw%3D%3D.RsgQQnMDVSE2S8uwL4x4qwWjn4XQWfIWVu6cEOoBet9PuJ1RwR4l5gAwFhR6DlLwYSazKvY7taeQQrajgXxZ7IOupYFIFQg3kHxlhXr6%2Fis%3D) 问题来了,如何反向解码呢?知道了String类型的secretkey,如果转变成SecretKey类型呢? 大概过程我能想到,是`Decoders.BASE64.decode(secretString)`,但是后面想不到了,有谁知道吗?