RSA加密：java和android之间的差异

/**
* 加密过程
* @param publicKey 公钥
* @param plainTextData 明文数据
* @return
* @throws Exception 加密过程中的异常信息
*/
public byte[] encrypt(RSAPublicKey publicKey, byte[] plainTextData) throws Exception{
if(publicKey== null){
throw new Exception("加密公钥为空, 请设置");
}
Cipher cipher= null;
try {
cipher= Cipher.getInstance("RSA");//, new BouncyCastleProvider());
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
byte[] output= cipher.doFinal(plainTextData);
return output;
} catch (NoSuchAlgorithmException e) {
throw new Exception("无此加密算法");
} catch (NoSuchPaddingException e) {
e.printStackTrace();
return null;
}catch (InvalidKeyException e) {
throw new Exception("加密公钥非法,请检查");
} catch (IllegalBlockSizeException e) {
throw new Exception("明文长度非法");
} catch (BadPaddingException e) {
throw new Exception("明文数据已损坏");
}
}


/**
* 解密过程
* @param privateKey 私钥
* @param cipherData 密文数据
* @return 明文
* @throws Exception 解密过程中的异常信息
*/
public byte[] decrypt(RSAPrivateKey privateKey, byte[] cipherData) throws Exception{
if (privateKey== null){
throw new Exception("解密私钥为空, 请设置");
}
Cipher cipher= null;
try {
cipher= Cipher.getInstance("RSA");//, new BouncyCastleProvider());
cipher.init(Cipher.DECRYPT_MODE, privateKey);
System.out.println(cipherData.length);
byte[] output= cipher.doFinal(cipherData);
return output;
} catch (NoSuchAlgorithmException e) {
throw new Exception("无此解密算法");
} catch (NoSuchPaddingException e) {
e.printStackTrace();
return null;
}catch (InvalidKeyException e) {
throw new Exception("解密私钥非法,请检查");
} catch (IllegalBlockSizeException e) {
throw new Exception("密文长度非法");
} catch (BadPaddingException e) {
throw new Exception("密文数据已损坏");
}
}

问题：android这边加密后 发送密文给java服务端 java服务端为什么一直 throw new Exception("密文数据已损坏"); 而android端自己本地 用RSA加密 再自己解密 过程完全没问题。。客户端和服务端都用上面代码加密和解密的。。。各位大神急啊 请收下小弟的膝盖