HttpUtil Class — netty Architecture

Source Code

codec-http/src/main/java/io/netty/handler/codec/http/HttpUtil.java lines 38–818

public final class HttpUtil {

    private static final AsciiString CHARSET_EQUALS = AsciiString.of(HttpHeaderValues.CHARSET + "=");
    private static final AsciiString SEMICOLON = AsciiString.cached(";");
    private static final String COMMA_STRING = String.valueOf(COMMA);

    private HttpUtil() { }

    /**
     * Determine if a uri is in origin-form according to
     * <a href="https://datatracker.ietf.org/doc/html/rfc9112#section-3.2.1">RFC 9112, 3.2.1</a>.
     */
    public static boolean isOriginForm(URI uri) {
        return isOriginForm(uri.toString());
    }

    /**
     * Determine if a string uri is in origin-form according to
     * <a href="https://datatracker.ietf.org/doc/html/rfc9112#section-3.2.1">RFC 9112, 3.2.1</a>.
     */
    public static boolean isOriginForm(String uri) {
        return uri.startsWith("/");
    }

    /**
     * Determine if a uri is in asterisk-form according to
     * <a href="https://datatracker.ietf.org/doc/html/rfc9112#section-3.2.4">RFC 9112, 3.2.4</a>.
     */
    public static boolean isAsteriskForm(URI uri) {
        return isAsteriskForm(uri.toString());
    }

    /**
     * Determine if a string uri is in asterisk-form according to
     * <a href="https://datatracker.ietf.org/doc/html/rfc9112#section-3.2.4">RFC 9112, 3.2.4</a>.
     */
    public static boolean isAsteriskForm(String uri) {
        return "*".equals(uri);
    }

    static void validateRequestLineTokens(HttpMethod method, String uri) {
        // The HttpVersion class does its own validation, and it's not possible for subclasses to circumvent it.
        // The HttpMethod class does its own validation, but subclasses might circumvent it.
        if (method.getClass() != HttpMethod.class) {
            if (!isEncodingSafeStartLineToken(method.asciiName())) {
                throw new IllegalArgumentException(
                        "The HTTP method name contain illegal characters: " + method.asciiName());
            }
        }

        if (!isEncodingSafeStartLineToken(uri)) {
            throw new IllegalArgumentException("The URI contain illegal characters: " + uri);
        }
    }

    /**
     * Validate that the given request line token is safe for verbatim encoding to the network.
     * This does not fully check that the token – HTTP method, version, or URI – is valid and formatted correctly.
     * Only that the token does not contain characters that would break or
     * desynchronize HTTP message parsing of the start line wherein the token would be included.
     * <p>
     * See <a href="https://datatracker.ietf.org/doc/html/rfc9112#name-request-line">RFC 9112, 3.</a>
     *
     * @param token The token to check.
     * @return {@code true} if the token is safe to encode verbatim into the HTTP message output stream,
     * otherwise {@code false}.
     */
    public static boolean isEncodingSafeStartLineToken(CharSequence token) {
        int lenBytes = token.length();
        for (int i = 0; i < lenBytes; i++) {
            char ch = token.charAt(i);
            // this is to help AOT compiled code which cannot profile the switch
            if (ch <= ' ') {
                switch (ch) {
                    case '\n':
                    case '\r':
                    case ' ':
                        return false;
                }
            }
        }