ソースコード内のパスワードを安全に処理するにはどうすればよいですか?

import java.util.Arrays;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.PBEParameterSpec;

public class PasswordEncryptionExample {
    private static final char[] PASSWORD = "Unauthorized_Personel_Is_Unauthorized".toCharArray();
    private static final byte[] SALT = {
            (byte) 0xde, (byte) 0x33, (byte) 0x10, (byte) 0x12,
            (byte) 0xde, (byte) 0x33, (byte) 0x10, (byte) 0x12
    };

    public static void main(String[] args) throws Exception {
        String password = "LetMePass_Word";
        char[] passwordArray = password.toCharArray();
        
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("PBEWithMD5AndDES");
        SecretKey key = keyFactory.generateSecret(new PBEKeySpec(PASSWORD));
        Cipher pbeCipher = Cipher.getInstance("PBEWithMD5AndDES");
        pbeCipher.init(Cipher.ENCRYPT_MODE, key, new PBEParameterSpec(SALT, 20));

        byte[] encryptedPassword = pbeCipher.doFinal(passwordArray);
        
        // Cleanup password data sources
        Arrays.fill(passwordArray, (char) 0);
        Arrays.fill(encryptedPassword, (byte) 0);
        
        // Decrypt the encrypted password
        pbeCipher.init(Cipher.DECRYPT_MODE, key, new PBEParameterSpec(SALT, 20));
        byte[] decryptedPassword = pbeCipher.doFinal(encryptedPassword);
        
        String decryptedPasswordString = new String(decryptedPassword);
        System.out.println("Decrypted password: " + decryptedPasswordString);
    }
}