记录一下：Java8和Java11对sun.misc.BASE64Encoder的替换

JDK 8之后的版本中针对sun.misc.BASE64Encoder 使用方法进行了修改升级，

JDK 8中：

BASE64Decoder decoder = new BASE64Decoder();
byte[] bytes = decoder.decodeBuffer(str);
BASE64Decoder decoder = new BASE64Decoder();
byte[] bytes = decoder.decodeBuffer(str);

JDK 11中变更为：

Base64.Decoder decoder = Base64.getMimeDecoder();
byte[] bytes = decoder.decode(str);
Base64.Decoder decoder = Base64.getMimeDecoder();
byte[] bytes = decoder.decode(str);