import java.util.Base64;

public class Base64Util {
  /**
      * Encodes byte array to Base64 string
      *
      * @param bytes Original binary data
      * @return Base64 encoded string
      *
      * Usage scenario: Convert encrypted binary data to safely transmittable text format,
      *                suitable for HTTP request parameter encapsulation.
      */
      public static String encodeByte(byte[] bytes) {
          return Base64.getEncoder().encodeToString(bytes);
      }
      /**
      * Decodes Base64 string to byte array
      *
      * @param str Base64 encoded string
      * @return Decoded original binary data
      *
      * Usage scenario: Convert Base64 data from API responses to binary,
      *                preparing for subsequent decryption operations.
      */
      public static byte[] decodeString(String str) {
          return Base64.getDecoder().decode(str);
      }
  }