Illegal key size or default parameters

java中使用AES對稱加密後，請求報錯：

Caused by: java.lang.RuntimeException: java.security.InvalidKeyException: Illegal key size or default parameters
        at com.btzh.util.AESUtil.encrypt(AESUtil.java:18)
        at com.btzh.service.impl.SiThirdSystemServiceImpl.mapSystemParams(SiThirdSystemServiceImpl.java:32)
        at com.btzh.resource.SiThirdSystemResource.mapSystemParams(SiThirdSystemResource.java:41)
        ... 43 common frames omitted
Caused by: java.security.InvalidKeyException: Illegal key size or default parameters
        at javax.crypto.Cipher.checkCryptoPerm(Cipher.java:1026)
        at javax.crypto.Cipher.implInit(Cipher.java:801)
        at javax.crypto.Cipher.chooseProvider(Cipher.java:864)
        at javax.crypto.Cipher.init(Cipher.java:1249)
        at javax.crypto.Cipher.init(Cipher.java:1186)
        at com.btzh.util.AESUtil.encrypt(AESUtil.java:15)

原因是美國的出口限制，Sun通過權限文件（local_policy.jar、US_export_policy.jar）做了相應限制。密鑰長度最大128，對於需要更大長度的場景則會拋出上面異常。

解決辦法是下載Oracle官方網站上的無政策限制權限文件，下載鏈接：

jdk8：https://www.oracle.com/technetwork/java/javase/downloads/jce8-download-2133166.html

下載後將%JAVA_HOME%\jre\lib\security中的local_policy.jar 和US_export_policy.jar替換爲下載包中的的local_policy.jar 和US_export_policy.jar。