RSA public private key encryption tool class

import org.apache.commons.codec.binary.Base64;
import javax.crypto.Cipher;
import java.nio.charset.StandardCharsets;
import java.security.*;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

public class RSAEncryptUtil {


    /**
     *  Public key encryption 
     *
     * @param content    Content 
     * @param publicKey  Public key 
     * @return  Encrypted ciphertext 
     * @throws Exception  Abnormal information 
     */
    public static String encrypt(String content, String publicKey) throws Exception {
        //base64 Encoded public key 
        byte[] decoded = Base64.decodeBase64(publicKey);
        RSAPublicKey pubKey = (RSAPublicKey) KeyFactory.getInstance("RSA").generatePublic(new X509EncodedKeySpec(decoded));
        //RSA encryption 
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.ENCRYPT_MODE, pubKey);
        return Base64.encodeBase64String(cipher.doFinal(content.getBytes(StandardCharsets.UTF_8)));
    }

    /**
     *  Private key decryption 
     *
     * @param content     Content 
     * @param privateKey  Private key 
     * @return  Decrypted string 
     * @throws Exception  abnormal 
     */
    public static String decrypt(String content, String privateKey) throws Exception {
        byte[] inputByte = Base64.decodeBase64(content.getBytes(StandardCharsets.UTF_8));
        byte[] decoded = Base64.decodeBase64(privateKey);
        RSAPrivateKey priKey = (RSAPrivateKey) KeyFactory.getInstance("RSA").generatePrivate(new PKCS8EncodedKeySpec(decoded));
        //RSA Decrypt 
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.DECRYPT_MODE, priKey);
        return new String(cipher.doFinal(inputByte));
    }

    /**
     *  Randomly generate key pairs 
     */
    public static KeyPair genKeyPair() throws Exception {
        // KeyPairGenerator Class is used to generate public and private key pairs , be based on RSA Algorithms generate objects 
        KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");
        keyPairGen.initialize(512, new SecureRandom());
        return keyPairGen.generateKeyPair();
    }

    public static void main(String[] args) throws Exception {

        KeyPair keyPair = genKeyPair();
        RSAPrivateKey privateKeyRSA = (RSAPrivateKey) keyPair.getPrivate();   //  Get the private key 
        RSAPublicKey publicKeyRSA = (RSAPublicKey) keyPair.getPublic();  //  Get the public key 
        String publicKey = new String(Base64.encodeBase64(publicKeyRSA.getEncoded()));
        //  Get the private key string 
        String privateKey = new String(Base64.encodeBase64((privateKeyRSA.getEncoded())));

        String encrypt = encrypt("ldskjfsdlkjllkjlkj", publicKey);
        System.out.println(" Encrypted ciphertext ：" + encrypt);

        String decrypt = decrypt(encrypt, privateKey);
        System.out.println(" Decrypt the ciphertext ：" + decrypt);

    }


}