// Test that unicode strings are properly encoded/decoded
        String unicodeString = "日本語テスト";
        String encoded = BaseEncoding.base64().encode(unicodeString.getBytes(StandardCharsets.UTF_8));
        String decoded = new String(BaseEncoding.base64().decode(encoded), StandardCharsets.UTF_8);

        assertEquals(unicodeString, decoded);
    }

    @Test

        final byte[] decoded = Base64Util.decode(encoded);
        assertEquals("Decoded should have same length", 2, decoded.length);
        assertEquals("First byte should match", twoBytes[0], decoded[0]);
        assertEquals("Second byte should match", twoBytes[1], decoded[1]);
    }

    /**
     * Test backward compatibility with standard Base64
     *
     * @throws Exception
     */

  }

  private fun testToUrl(
    codePoint: Int,
    encoding: UrlComponentEncodingTester.Encoding,
    component: Component,
  ) {
    val encoded = encoding.encode(codePoint)
    val httpUrl = component.urlString(encoded).toHttpUrl()
    val javaNetUrl = httpUrl.toUrl()
    if (javaNetUrl.toString() != javaNetUrl.toString()) {
      fail("Encoding $component $codePoint using $encoding")
    }
  }

    }

    /**
     * Encodes an object name to a URL-safe base64 string.
     *
     * @param objectName the object name to encode
     * @return base64 encoded string
     */
    protected static String encodeId(final String objectName) {
        if (objectName == null) {
            return StringUtil.EMPTY;
        }

    return encode(bytes, 0, bytes.length);
  }

  /**
   * Encodes the specified range of the specified byte array, and returns the encoded {@code
   * String}.
   */
  public final String encode(byte[] bytes, int off, int len) {
    checkPositionIndexes(off, off + len, bytes.length);
    StringBuilder result = new StringBuilder(maxEncodedSize(len));
    try {
      encodeTo(result, bytes, off, len);

**FastAPI** will make sure to read that data from the right place instead of JSON.

/// note | Technical Details

Data from forms is normally encoded using the "media type" `application/x-www-form-urlencoded`.

But when the form includes files, it is encoded as `multipart/form-data`. You'll read about handling files in the next chapter.

     */
    protected Base64Util() {
    }

    /**
     * Encodes data in Base64.
     * <p>
     * This method uses {@link java.util.Base64.Encoder} for encoding.
     * </p>
     *
     * @param inData
     *            The data to encode
     * @return The encoded data, or an empty string if the input is null or empty
     */
    public static String encode(final byte[] inData) {
        if (ArrayUtil.isEmpty(inData)) {

// ContainsAny reports whether any of the UTF-8-encoded code points in chars are within b.
func ContainsAny(b []byte, chars string) bool {
	return IndexAny(b, chars) >= 0
}

// ContainsRune reports whether the rune is contained in the UTF-8-encoded byte slice b.
func ContainsRune(b []byte, r rune) bool {
	return IndexRune(b, r) >= 0
}

// ContainsFunc reports whether any of the UTF-8-encoded code points r within b satisfy f(r).

      encodeBase64Lines(pkcs1Bytes())
      append("-----END RSA PRIVATE KEY-----\n")
    }
  }

  private fun pkcs1Bytes(): ByteString {
    val decoded = CertificateAdapters.privateKeyInfo.fromDer(keyPair.private.encoded.toByteString())
    return decoded.privateKey
  }

  /** Build a held certificate with reasonable defaults. */
  class Builder {
    private var notBefore = -1L
    private var notAfter = -1L

## Base64 vs Files { #base64-vs-files }

Consider first if you can use [Request Files](../tutorial/request-files.md) for uploading binary data and [Custom Response - FileResponse](./custom-response.md#fileresponse--fileresponse-) for sending binary data, instead of encoding it in JSON.

JSON can only contain UTF-8 encoded strings, so it can't contain raw bytes.