报错堆栈如下：
Caused by: java.security.InvalidKeyException:Illegal key size or default parameters
at javax.crypto.Cipher.a(DashoA13*..)~[na:1.6] at javax.crypto.Cipher.a(DashoA13*..)~[na:1.6] at javax.crypto.Cipher.a(DashoA13*..)~[na:1.6] at javax.crypto.Cipher.init(DashoA13*..)~[na:1.6] at javax.crypto.Cipher.init(DashoA13*..)~[na:1.6] at my.package.Something.decode(RC4Decoder.java:25)~[my.package.jar:na]
Google到问题原因，链接地址如下：
http://stackoverflow.com/questions/6481627/java-security-illegal-key-size-or-default-parameters
根据回答找到下载新jar包链接地址如下：
http://www.oracle.com/technetwork/java/javase/downloads/jce-6-download-429243.html
把里面的两个jar包：local_policy.jar 和 US_export_policy.jar 替换掉原来安装目录C:\Program Files\Java\jre6\lib\security 下的两个jar包接可以了
然后就重新运行程序，不会报错了，测试代码如下：
public class Test {
public static void main(String[] args) throws Exception {
KeyGenerator keyGen = KeyGenerator.getInstance("AES");
keyGen.init(256);
SecretKey key = keyGen.generateKey();
ObjectOutputStream oop = new ObjectOutputStream(new
FileOutputStream("c:\\key.dat"));
oop.writeObject(key);
oop.close();
String strTest = "Hello, Jason";
byte[] strAfterAES = encryptData(strTest.getBytes());
System.out.println(new String(strAfterAES));
byte[] strOriContent = decryptData(strAfterAES);
System.out.println(new String(strOriContent));
}
public static byte[] encryptData(byte[] input) throws Exception {
ObjectInputStream in = new ObjectInputStream(new FileInputStream("c:\\key.dat"));
SecretKey aeskey = (SecretKey) in.readObject();
Cipher c1 = Cipher.getInstance("AES");
c1.init(Cipher.ENCRYPT_MODE, aeskey);
byte[] cipherByte = c1.doFinal(input);
return cipherByte;
}
public static byte[] decryptData(byte[] input) throws Exception {
ObjectInputStream in = new ObjectInputStream(new FileInputStream("c:\\key.dat"));
SecretKey aeskey = (SecretKey) in.readObject();
Cipher c1 = Cipher.getInstance("AES");
c1.init(Cipher.DECRYPT_MODE, aeskey);
byte[] clearByte = c1.doFinal(input);
return clearByte;
}
}
BTW:
If ur JVM is IBM JVM pls refer to the below link to update the unlimited key size jars