java.security.InvalidKeyException: Illegal key size or default parameters**
使用AES加密时，当密钥大于128字节时，代码会抛出Java.security.InvalidKeyException: Illegal key size or default parameters
Illegal key size or default parameters是指密钥长度是受限制的，java运行时环境读到的是受限的policy文件。文件位于${java_home}/jre/lib/security
点击下载相应文件：
Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files 6 Download
Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files 7 Download
Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files 8 Download
replace the file in ${java.home}/jre/lib/security/
