RSA加密算法（后端）

public class RSA {private static final String RSA_ALGORITHM = "RSA";/*** 生成RSA密钥对** @return RSA密钥对*/public static KeyPair generateKeyPair() throws NoSuchAlgorithmException {KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(RSA_ALGORITHM);keyPairGenerator.initialize(2048); // 密钥大小为2048位return keyPairGenerator.generateKeyPair();}/*** 使用公钥加密数据** @param data      待加密的数据* @param publicKey 公钥* @return 加密后的数据*/public static String encrypt(String data, PublicKey publicKey) throws Exception {Cipher cipher = Cipher.getInstance(RSA_ALGORITHM);cipher.init(Cipher.ENCRYPT_MODE, publicKey);byte[] encryptedData = cipher.doFinal(data.getBytes(StandardCharsets.UTF_8));return Base64.getEncoder().encodeToString(encryptedData);}/*** 使用私钥解密数据** @param encryptedData 加密后的数据* @param privateKey    私钥* @return 解密后的数据*/public static String decrypt(String encryptedData, PrivateKey privateKey) throws Exception {byte[] decodedData = Base64.getDecoder().decode(encryptedData);Cipher cipher = Cipher.getInstance(RSA_ALGORITHM);cipher.init(Cipher.DECRYPT_MODE, privateKey);byte[] decryptedData = cipher.doFinal(decodedData);return new String(decryptedData, StandardCharsets.UTF_8);}public static void main(String[] args) throws Exception {KeyPair keyPair = generateKeyPair();PublicKey publicKey = keyPair.getPublic();PrivateKey privateKey = keyPair.getPrivate();String data = "Hello World";String encryptedData = encrypt(data, publicKey);System.out.println("加密后的数据：" + encryptedData);String decryptedData = decrypt(encryptedData, privateKey);System.out.println("解密后的数据：" + decryptedData);}
}