解析请求头的简单方法

Question

我需要编写自定义 java http 服务器。所以我尝试基于此示例： http://java.sun.com /developer/technicalArticles/Networking/Webserver/ 。问题之一是在不使用任何内置函数的情况下解析请求标头。 Exmaple 展示了这种方法：

   void handleClient() throws IOException {
        InputStream is = new BufferedInputStream(s.getInputStream());
        PrintStream ps = new PrintStream(s.getOutputStream());
        /* we will only block in read for this many milliseconds
         * before we fail with java.io.InterruptedIOException,
         * at which point we will abandon the connection.
         */
        s.setSoTimeout(WebServer.timeout);
        s.setTcpNoDelay(true);
        /* zero out the buffer from last time */
        for (int i = 0; i < BUF_SIZE; i++) {
            buf[i] = 0;
        }
        try {
            /* We only support HTTP GET/HEAD, and don't
             * support any fancy HTTP options,
             * so we're only interested really in
             * the first line.
             */
            int nread = 0, r = 0;

outerloop:
            while (nread < BUF_SIZE) {
                r = is.read(buf, nread, BUF_SIZE - nread);
                if (r == -1) {
                    /* EOF */
                    return;
                }
                int i = nread;
                nread += r;
                for (; i < nread; i++) {
                    if (buf[i] == (byte)'\n' || buf[i] == (byte)'\r') {
                        /* read one line */
                        break outerloop;
                    }
                }
            }

            /* are we doing a GET or just a HEAD */
            boolean doingGet;
            /* beginning of file name */
            int index;
            if (buf[0] == (byte)'G' &&
                buf[1] == (byte)'E' &&
                buf[2] == (byte)'T' &&
                buf[3] == (byte)' ') {
                doingGet = true;
                index = 4;
            } else if (buf[0] == (byte)'H' &&
                       buf[1] == (byte)'E' &&
                       buf[2] == (byte)'A' &&
                       buf[3] == (byte)'D' &&
                       buf[4] == (byte)' ') {
                doingGet = false;
                index = 5;
            } else {
                /* we don't support this method */
                ps.print("HTTP/1.0 " + HTTP_BAD_METHOD +
                           " unsupported method type: ");
                ps.write(buf, 0, 5);
                ps.write(EOL);
                ps.flush();
                s.close();
                return;
            }

            int i = 0;
            /* find the file name, from:
             * GET /foo/bar.html HTTP/1.0
             * extract "/foo/bar.html"
             */
            for (i = index; i < nread; i++) {
                if (buf[i] == (byte)' ') {
                    break;
                }
            }
            String fname = (new String(buf, 0, index,
                      i-index)).replace('/', File.separatorChar);
            if (fname.startsWith(File.separator)) {
                fname = fname.substring(1);
            }
            File targ = new File(WebServer.root, fname);
            if (targ.isDirectory()) {
                File ind = new File(targ, "index.html");
                if (ind.exists()) {
                    targ = ind;
                }
            }
            boolean OK = printHeaders(targ, ps);
            if (doingGet) {
                if (OK) {
                    sendFile(targ, ps);
                } else {
                    send404(targ, ps);
                }
            }
        } finally {
            s.close();
        }
    }

所以基本上请求类型是使用 byte bufferedinoutstream 读取的。有没有更好、也许更快的方法来做到这一点？我还需要支持 POST 请求。