Helper methods

HttpRequestHandler.java

private Map<String, String> parseRequestHeaders(BufferedReader in) throws IOException {
    Map<String, String> headers = new HashMap<>();
    String line;
    while ((line = in.readLine()) != null && !line.isEmpty()) {
        int idx = line.indexOf(':');
        if (idx > 0) {
            headers.put(line.substring(0, idx).toLowerCase(), line.substring(idx + 1).trim());
        }
    }
    return headers;
}

private byte[] readFile(File file) throws IOException {
    byte[] res;
    try (FileInputStream fis = new FileInputStream(file)) {
        int length = (int) file.length();
        res = new byte[length];
        //noinspection ResultOfMethodCallIgnored
        fis.read(res, 0, length);
    }
    return res;
}

private void writeResponseHeaders(PrintWriter out, String protocol, String status, String date, int length) {
    out.println(protocol + status);
    out.println(SERVER + config.getProperty(SERVER_VERSION_PARAM));
    out.println(DATE + date);
    out.println(CONTENT_TYPE + "text/html; charset=utf-8");
    out.println(CONTENT_LENGTH + length);
    out.println(CONNECTION + "close");
    out.println();
    out.flush();
}

private void log(InetAddress remoteAddress, String date, String request, String status, String ua) {
    logger.printf("%s [%s] \"%s\"%s %s\n", remoteAddress.getHostAddress(), date, request, status, ua);
}