// 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

  }

  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")
    }
  }

    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.

// 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.

            String encoded = permissionHelper.encode(value);
            if (encoded != null) {
                String decoded = permissionHelper.decode(encoded);
                assertNotNull("Decoded value should not be null for: " + value, decoded);
                assertEquals("Decoded value should match original: " + value + " -> " + encoded + " -> " + decoded, value, decoded);
            }
        }
    }

    /**
     * Returns a new instance configured with a default encode set for the ASCII range. The specific
     * rules vary per-component: for example, '?' may be identity-encoded in a fragment, but must be
     * percent-encoded in a path.
     *
     * See https://url.spec.whatwg.org/#percent-encoded-bytes
     */
    fun newInstance(): UrlComponentEncodingTester =
      UrlComponentEncodingTester()

 * query the fragment is not sent to the webserver: it's private to the client.
 *
 * ## Encoding
 *
 * Each component must be encoded before it is embedded in the complete URL. As we saw above, the
 * string `cute #puppies` is encoded as `cute%20%23puppies` when used as a query parameter value.
 *
 * ### Percent encoding
 *