Http2StaticFileServerHandler Class — netty Architecture

Source Code

example/src/main/java/io/netty/example/http2/file/Http2StaticFileServerHandler.java lines 108–380

public class Http2StaticFileServerHandler extends ChannelDuplexHandler {

    public static final String HTTP_DATE_FORMAT = "EEE, dd MMM yyyy HH:mm:ss zzz";
    public static final String HTTP_DATE_GMT_TIMEZONE = "GMT";
    public static final int HTTP_CACHE_SECONDS = 60;

    private Http2FrameStream stream;

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        if (msg instanceof Http2HeadersFrame) {
            Http2HeadersFrame headersFrame = (Http2HeadersFrame) msg;
            this.stream = headersFrame.stream();

            if (!GET.toString().equals(headersFrame.headers().method().toString())) {
                sendError(ctx, METHOD_NOT_ALLOWED);
                return;
            }

            final String uri = headersFrame.headers().path().toString();
            final String path = sanitizeUri(uri);
            if (path == null) {
                sendError(ctx, FORBIDDEN);
                return;
            }

            File file = new File(path);
            if (file.isHidden() || !file.exists()) {
                sendError(ctx, NOT_FOUND);
                return;
            }

            if (file.isDirectory()) {
                if (uri.endsWith("/")) {
                    sendListing(ctx, file, uri);
                } else {
                    sendRedirect(ctx, uri + '/');
                }
                return;
            }

            if (!file.isFile()) {
                sendError(ctx, FORBIDDEN);
                return;
            }

            // Cache Validation
            CharSequence ifModifiedSince = headersFrame.headers().get(HttpHeaderNames.IF_MODIFIED_SINCE);
            if (ifModifiedSince != null && !ifModifiedSince.toString().isEmpty()) {
                SimpleDateFormat dateFormatter = new SimpleDateFormat(HTTP_DATE_FORMAT, Locale.US);
                Date ifModifiedSinceDate = dateFormatter.parse(ifModifiedSince.toString());

                // Only compare up to the second because the datetime format we send to the client
                // does not have milliseconds
                long ifModifiedSinceDateSeconds = ifModifiedSinceDate.getTime() / 1000;
                long fileLastModifiedSeconds = file.lastModified() / 1000;
                if (ifModifiedSinceDateSeconds == fileLastModifiedSeconds) {
                    sendNotModified(ctx);
                    return;
                }
            }

            RandomAccessFile raf;
            try {
                raf = new RandomAccessFile(file, "r");
            } catch (FileNotFoundException ignore) {
                sendError(ctx, NOT_FOUND);
                return;
            }
            long fileLength = raf.length();

            Http2Headers headers = new DefaultHttp2Headers();
            headers.status("200");
            headers.setLong(HttpHeaderNames.CONTENT_LENGTH, fileLength);

            setContentTypeHeader(headers, file);
            setDateAndCacheHeaders(headers, file);

            // Write the initial line and the header.
            ctx.writeAndFlush(new DefaultHttp2HeadersFrame(headers).stream(stream));