code: public static SecretKey generateKey(final byte[] key) {
          return new SecretKey() {
  
              private byte[] k;
  
              {
                  if (key.length == 16) {
                      k = key;
                  } else {
                      k = new byte[16];
                      System.arraycopy(key, 0, k, 0, key.length < 16 ? key.length : 16);
                  }
              }
  
              @Override
              public String getAlgorithm() {
                  return "AES";
              }
  
              @Override
              public String getFormat() {
                  return "RAW";
              }
  
              @Override
              public byte[] getEncoded() {
                  return k;
              }
          };
      }
docs: 16 bytes max,  128-bit encription