How to encrypt an object and write it to file in Java and decrypt it

java-object-encryption-with-file.java

import javax.crypto.*;
import javax.crypto.spec.IvParameterSpec;
import java.io.*;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

public class Main {

    public static void main(String[] args) throws IOException, ClassNotFoundException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidAlgorithmParameterException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException {

        // encrypt an java object and write to file

        // create a java object
        Employee em1 = new Employee("steve", "123");

        // generate symmetric key
        KeyGenerator generator = KeyGenerator.getInstance( "AES" );
        SecretKey key = generator.generateKey();

        // generate IV
        SecureRandom random = new SecureRandom();
        byte [] iv = new byte [16];
        random.nextBytes( iv );

        // create cipher
        Cipher cipher = Cipher.getInstance( key.getAlgorithm() + "/CBC/PKCS5Padding" );
        cipher.init( Cipher.ENCRYPT_MODE, key, new IvParameterSpec( iv ) );

        // create sealed object
        SealedObject sealedEm1 = new SealedObject( em1, cipher);

        // Create stream
        FileOutputStream fos = new FileOutputStream("out.aes");
        BufferedOutputStream bos = new BufferedOutputStream(fos);
        CipherOutputStream cos = new CipherOutputStream(bos, cipher);
        ObjectOutputStream oos = new ObjectOutputStream(cos);
        oos.writeObject( sealedEm1 );
        oos.close();


        // read an encrypted java object from a file and decrypt it


        // turn the mode of cipher to decryption
        cipher.init( Cipher.DECRYPT_MODE, key, new IvParameterSpec( iv ) ); // reuse the key and iv generated before

        // create stream
        CipherInputStream cipherInputStream = new CipherInputStream( new BufferedInputStream( new FileInputStream( "out.aes" ) ), cipher );
        ObjectInputStream inputStream = new ObjectInputStream( cipherInputStream );
        SealedObject sealedObject = (SealedObject) inputStream.readObject();
        Employee em2 = (Employee) sealedObject.getObject(cipher);
        System.out.println(em2.name);


    }
}

class Employee implements Serializable {
    public String name = "";
    public String ssn = "";

    public Employee(String name, String ssn) {
        this.name = name;
        this.ssn = ssn;
    }

}

Thanks