Java client side their encryption and decryption are sure
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But the Java end private key encrypted results brought Delphi to restore public key to decrypt not

 
Package com. Algorithm; 

Import the Java. IO. ByteArrayOutputStream; 
Import the Java. Math. BigInteger; 
Import the Java. Security. The Key; 
Import the Java. Security. KeyFactory; 
Import the Java. Security. KeyPair; 
Import the Java. Security. KeyPairGenerator; 
Import the Java. Security. NoSuchAlgorithmException; 
Import the Java. Security. PrivateKey; 
Import the Java. Security. PublicKey; 
Import the Java. Security. Signature; 
Import the Java. Security. Interfaces. RSAPrivateKey; 
Import the Java. Security. Interfaces. RSAPublicKey; 
Import the Java. Security. Spec. InvalidKeySpecException; 
Import the Java. Security. Spec. PKCS8EncodedKeySpec; 
Import the Java. Security. Spec. RSAPrivateKeySpec; 
Import the Java. Security. Spec. RSAPublicKeySpec; 
Import the Java. Security. Spec. X509EncodedKeySpec; 
Import the Java. Util. HashMap; 
Import the Java. Util. The Map; 

The import javax.mail. Crypto. Cipher; 

The import org.apache.com mons. Codec. Binary. Hex; 

/* * 
* RSA asymmetric encryption algorithm security coding component 
* @ author Administrator 
* 
*/
Public abstract class RSACoder {
//asymmetric encryption key algorithms 
Public static final String KEY_ALGORITHM="RSA"; 
//digital signature signature verification algorithm 
Public static final String SIGNATURE_ALGORRITHM="SHA1withRSA"; 
//public key 
Private static final String PUBLIC_KEY="RSAPublicKey"; 
//private key 
Private static final String PRIVATE_KEY="RSAPrivateKey"; 
//RSA key length, defaults to 1024, the key length must be in multiples of 64, in the range between 521 ~ 65526 
Private static final ints KEY_SIZE=512; 

Private static final ints MAX_DECRYPT_BLOCK=64; 



Public static byte [] getPublicKey (String modulus, String publicExponent) throws NoSuchAlgorithmException, InvalidKeySpecException {
BigInteger bigIntPrivateExponent=new BigInteger (publicExponent); 
BigInteger bigIntModulus=new BigInteger (modulus); 

RSAPublicKeySpec keySpec=new RSAPublicKeySpec (bigIntModulus bigIntPrivateExponent); 
KeyFactory KeyFactory=KeyFactory. GetInstance (" RSA "); 
PublicKey PublicKey=keyFactory. GeneratePublic (keySpec); 
Return publicKey. GetEncoded (); 
} 
/* * 
* public key decryption 
* @ param data to decrypt data 
* @ param key public key 
* @ return byte [] to decrypt data 
* @ throws the Exception 
*/
Public static byte [] decryptByPublicKey (byte [] data, byte [] key) throws the Exception 
{
//public key 
X509EncodedKeySpec x509KeySpec=new X509EncodedKeySpec (key); 
KeyFactory KeyFactory=KeyFactory. GetInstance (KEY_ALGORITHM); 
//generated public key 
PublicKey PublicKey=keyFactory. GeneratePublic (x509KeySpec); 
//to decrypt the data 
Cipher Cipher=Cipher. GetInstance (keyFactory getAlgorithm ()); 
Cipher. The init (cipher DECRYPT_MODE, publicKey); 
Return cipher. DoFinal (data); 
} 

/* * 
* private key encryption 
* @ param data to be encrypted data 
* @ param key private key 
* @ return byte [] to encrypt data 
* @ throws the Exception 
*/
Public static byte [] encryptByPrivateKey (byte [] data, byte [] key) throws the Exception 
{
//private key 
PKCS8EncodedKeySpec pkcs8KeySpec=new PKCS8EncodedKeySpec (key); 
KeyFactory KeyFactory=KeyFactory. GetInstance (KEY_ALGORITHM); 
//private key generated 
PrivateKey PrivateKey=keyFactory. GeneratePrivate (pkcs8KeySpec); 
//the data encryption 
Cipher Cipher=Cipher. GetInstance (keyFactory getAlgorithm ()); 
Cipher. The init (cipher ENCRYPT_MODE, privateKey); 
Return cipher. DoFinal (data); 
} 
/* * 
* private key encryption 
* @ param data to be encrypted data 
* @ param key private key 
* @ return byte [] to encrypt data 
* @ throws the Exception 
*/
Public static byte [] encryptByPrivateKey (byte [] data, String key) throws the Exception 
{
Return encryptByPrivateKey (data, getKey (key)); 
} 

/* * 
* get the private key 
* @ param keyMap key Map 
* @ return byte [] private key 
* @ throws the Exception 
*/
Public static byte [] getPrivateKey (Map KeyMap) throws the Exception 
{
The Key Key=(Key) keyMap. Get (PRIVATE_KEY); 
The return key. GetEncoded (); 
} 
/* * 
* get the public key 
* @ param keyMap key Map 
* @ return byte [] public key 
* @ throws the Exception 
*/
Public static byte [] getPublicKey (Map KeyMap) throws the Exception 
{
The Key Key=(Key) keyMap. Get (PUBLIC_KEY); 
The return key. GetEncoded (); 
} 

/* * 
* initialize the keys 
* @ the return key Map 
* @ throws the Exception 
*/
Public static Map InitKey () throws the Exception 
{
//instantiate the real key to the generator 
KeyPairGenerator keyPairGen=KeyPairGenerator. GetInstance (KEY_ALGORITHM); 
//initialize the key of generator 
KeyPairGen. The initialize (KEY_SIZE); 
//generate the key pair 
KeyPair KeyPair=keyPairGen. GenerateKeyPair (); 
//public key 
RSAPublicKey publicKey=(RSAPublicKey) keyPair. GetPublic (); nullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnullnull