HttpHeader.java

package com.firefly.codec.http2.model;

import java.nio.ByteBuffer;
import java.nio.charset.StandardCharsets;

import com.firefly.utils.collection.ArrayTrie;
import com.firefly.utils.collection.Trie;



public enum HttpHeader {
	
	/* ------------------------------------------------------------ */
    /** General Fields.
     */
    CONNECTION("Connection"),
    CACHE_CONTROL("Cache-Control"),
    DATE("Date"),
    PRAGMA("Pragma"),
    PROXY_CONNECTION ("Proxy-Connection"),
    TRAILER("Trailer"),
    TRANSFER_ENCODING("Transfer-Encoding"),
    UPGRADE("Upgrade"),
    VIA("Via"),
    WARNING("Warning"),
    NEGOTIATE("Negotiate"),

    /* ------------------------------------------------------------ */
    /** Entity Fields.
     */
    ALLOW("Allow"),
    CONTENT_ENCODING("Content-Encoding"),
    CONTENT_LANGUAGE("Content-Language"),
    CONTENT_LENGTH("Content-Length"),
    CONTENT_LOCATION("Content-Location"),
    CONTENT_MD5("Content-MD5"),
    CONTENT_RANGE("Content-Range"),
    CONTENT_TYPE("Content-Type"),
    EXPIRES("Expires"),
    LAST_MODIFIED("Last-Modified"),

    /* ------------------------------------------------------------ */
    /** Request Fields.
     */
    ACCEPT("Accept"),
    ACCEPT_CHARSET("Accept-Charset"),
    ACCEPT_ENCODING("Accept-Encoding"),
    ACCEPT_LANGUAGE("Accept-Language"),
    AUTHORIZATION("Authorization"),
    EXPECT("Expect"),
    FORWARDED("Forwarded"),
    FROM("From"),
    HOST("Host"),
    IF_MATCH("If-Match"),
    IF_MODIFIED_SINCE("If-Modified-Since"),
    IF_NONE_MATCH("If-None-Match"),
    IF_RANGE("If-Range"),
    IF_UNMODIFIED_SINCE("If-Unmodified-Since"),
    KEEP_ALIVE("Keep-Alive"),
    MAX_FORWARDS("Max-Forwards"),
    PROXY_AUTHORIZATION("Proxy-Authorization"),
    RANGE("Range"),
    REQUEST_RANGE("Request-Range"),
    REFERER("Referer"),
    TE("TE"),
    USER_AGENT("User-Agent"),
    X_FORWARDED_FOR("X-Forwarded-For"),
    X_FORWARDED_PROTO("X-Forwarded-Proto"),
    X_FORWARDED_SERVER("X-Forwarded-Server"),
    X_FORWARDED_HOST("X-Forwarded-Host"),

    /* ------------------------------------------------------------ */
    /** Response Fields.
     */
    ACCEPT_RANGES("Accept-Ranges"),
    AGE("Age"),
    ETAG("ETag"),
    LOCATION("Location"),
    PROXY_AUTHENTICATE("Proxy-Authenticate"),
    RETRY_AFTER("Retry-After"),
    SERVER("Server"),
    SERVLET_ENGINE("Servlet-Engine"),
    VARY("Vary"),
    WWW_AUTHENTICATE("WWW-Authenticate"),

    /* ------------------------------------------------------------ */
    /** Other Fields.
     */
    COOKIE("Cookie"),
    SET_COOKIE("Set-Cookie"),
    SET_COOKIE2("Set-Cookie2"),
    MIME_VERSION("MIME-Version"),
    IDENTITY("identity"),
    
    X_POWERED_BY("X-Powered-By"),
    HTTP2_SETTINGS("HTTP2-Settings"),

    /* ------------------------------------------------------------ */
    /** HTTP2 Fields.
     */
    C_METHOD(":method"),
    C_SCHEME(":scheme"),
    C_AUTHORITY(":authority"),
    C_PATH(":path"),
    C_STATUS(":status"),
    
    UNKNOWN("::UNKNOWN::");
	
	public final static Trie<HttpHeader> CACHE= new ArrayTrie<>(530);
    static
    {
        for (HttpHeader header : HttpHeader.values())
            if (header!=UNKNOWN)
                if (!CACHE.put(header.toString(),header))
                    throw new IllegalStateException();
    }
    
    private final String string;
    private final byte[] bytes;
    private final byte[] bytesColonSpace;
    private final ByteBuffer buffer;
    
    private HttpHeader(String s) {
        string = s;
        bytes = s.getBytes(StandardCharsets.UTF_8);
        bytesColonSpace = (s + ": ").getBytes(StandardCharsets.UTF_8);
        buffer = ByteBuffer.wrap(bytes);
    }
    
    public ByteBuffer toBuffer() {
        return buffer.asReadOnlyBuffer();
    }

    public byte[] getBytes() {
        return bytes;
    }

    public byte[] getBytesColonSpace() {
        return bytesColonSpace;
    }

    public boolean is(String s) {
        return string.equalsIgnoreCase(s);    
    }

    public String asString() {
        return string;
    }
    
    @Override
    public String toString() {
        return string;
    }
}