Java Security

I'm using SUNJce (JDK 1.5) to encrypt and decrypt with RSA algorithm, when i run the code as standalone (with my IDE), it works fine. but when i JAR my application and run the code,
Same thing with BouncyCastle provider too.
It gives

Exception in thread "main" java.security.spec.InvalidKeySpecException: java.secu
rity.InvalidKeyException: Invalid RSA public key
at sun.security.rsa.RSAKeyFactory.engineGeneratePublic(Unknown Source)
at java.security.KeyFactory.generatePublic(Unknown Source)

Following is the piece of code which reads the Public key

  private static PublicKey readPublicKey()
       throws Exception {

       String fl = "pubKey.dat";
       InputStream fis = RSACryption.class.getResourceAsStream(fl);
       int kl = fis.available();
       byte[] kb = new byte[kl];
       fis.read(kb);
       fis.close();
       String pubKey = encodeBASE64(kb);
       return getPublicKeyFromString(pubKey);
    }
    
    
        public static PublicKey getPublicKeyFromString(String key) throws Exception
        {
            KeyFactory keyFactory = KeyFactory.getInstance(ALGORITHM);
            EncodedKeySpec publicKeySpec = new X509EncodedKeySpec(Base64.decode(key));
            PublicKey publicKey = keyFactory.generatePublic(publicKeySpec); 
            return publicKey;
        }

Exception is thrown in

            PublicKey publicKey = keyFactory.generatePublic(publicKeySpec); 

The same methodology i had used before for other algorithms (Blowfish/ 3DES), all were fine.

The main idea is keeping the public key file in the jar and using getResourceAsStream.

Need Help

Thanks in advance