Netty HTTP 文件服务器

public class HttpFileServer {
    public void run(final int port, final String url) throws InterruptedException {
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap boot = new ServerBootstrap();
            boot.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class)
            .childHandler(new ChannelInitializer<SocketChannel>() {
                @Override
                protected void initChannel(SocketChannel ch) throws Exception {
                    ch.pipeline().addLast("http-decoder", new HttpRequestDecoder());
                    ch.pipeline().addLast("http-aggregator", new HttpObjectAggregator(65536));
                    ch.pipeline().addLast("http-encoder", new HttpResponseEncoder());
                    ch.pipeline().addLast("http-chunked", new ChunkedWriteHandler());
                    ch.pipeline().addLast("fileServerHandler", new HttpFileServerHandler(url));
                }
        });
            ChannelFuture cf =boot.bind("127.0.0.1",port).sync();
            System.out.println("Http文件目录服务器启动: [http://127.0.0.1](http://127.0.0.1):"+port+url);
            cf.channel().closeFuture().sync();
        } finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }
    public static void main(String[] args) throws InterruptedException {
        String url="/src/main/java/";
        new HttpFileServer().run(8080, url);
    }
}

public class HttpFileServerHandler extends SimpleChannelInboundHandler<FullHttpRequest> {
    HttpMethod GET = new HttpMethod("GET");
    private String url;
    private final Pattern ALLOWED_FILE_NAME = Pattern.compile("[A-Za-z0-9][-_A-Za-z0-9\\.]*");
    private final Pattern INSECURE_URI = Pattern.compile(".\*[<>&\"].\*");
    public HttpFileServerHandler(String url) {
        this.url = url;
    }
    @Override
    protected void messageReceived(ChannelHandlerContext ctx, FullHttpRequest request) throws Exception {
        if (!request.getDecoderResult().isSuccess()) {
            sendError(ctx, HttpResponseStatus.BAD_REQUEST);
            return;
        }
        if (request.getMethod() != HttpMethod.GET) {
            sendError(ctx, HttpResponseStatus.METHOD_NOT_ALLOWED);
            return;
        }
        final String uri = request.getUri();
        final String path = sanitizeUri(uri);
        if (path == null) {
            sendError(ctx, HttpResponseStatus.FORBIDDEN);
            return;
        }
        File file = new File(path);
        if (file.isHidden() || !file.exists()) {
            sendError(ctx, HttpResponseStatus.NOT_FOUND);
            return;
        }
        if (file.isDirectory()) {
            if (uri.endsWith("/")) {
                sendList(ctx, file);
            } else {
                sendRedirect(ctx, uri + '/');
            }
            return;
        }
        if (!file.isFile()) {
            sendError(ctx, HttpResponseStatus.FORBIDDEN);
            return;
        }
        RandomAccessFile randomAccessFile = null;
        try {
            randomAccessFile = new RandomAccessFile(file, "r");
        } catch (FileNotFoundException e) {
            sendError(ctx, HttpResponseStatus.NO_CONTENT);
            return;
        }
        long fileLength = randomAccessFile.length();
        HttpResponse response = new DefaultHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK);
        HttpHeaders.setContentLength(response, fileLength);
        setContentTypeHeader(response, file);
        if (HttpHeaders.isKeepAlive(request)) {
            response.headers().set(HttpHeaders.Names.CONNECTION, HttpHeaders.Values.KEEP_ALIVE);
        }
        ctx.write(response);
        ChannelFuture sendFileFuture;
        sendFileFuture = ctx.write(new ChunkedFile(randomAccessFile, 0, fileLength, 8192), ctx.newProgressivePromise());
        sendFileFuture.addListener(new ChannelProgressiveFutureListener() {
            @Override
            public void operationComplete(ChannelProgressiveFuture future) throws Exception {
                System.err.println(future.channel() + " transfer complete");
            }
            @Override
            public void operationProgressed(ChannelProgressiveFuture future, long progress, long total)
            throws Exception {
                if (total < 0) {
                    System.err.println(future.channel() + " transfer progress : " + progress);
                } else {
                    System.err.println(future.channel() + " transfer progress : " + progress + " / " + total);
                }
            }
    });
        ChannelFuture lastContentFuture = ctx.writeAndFlush(LastHttpContent.EMPTY_LAST_CONTENT);
        if (!HttpHeaders.isKeepAlive(request)) {
            lastContentFuture.addListener(ChannelFutureListener.CLOSE);
        }
    }
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        cause.printStackTrace();
        if (ctx.channel().isActive()) {
            sendError(ctx, HttpResponseStatus.INTERNAL_SERVER_ERROR);
        }
    }
    private void sendError(ChannelHandlerContext ctx, HttpResponseStatus status) {
        FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, status, Unpooled.copiedBuffer(
        "Failure :" + status + "\r\n", CharsetUtil.UTF_8));
        response.headers().set(HttpHeaders.Names.CONTENT_TYPE, "text/plain; charset=UTF-8");
        ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE);
    }
    public String sanitizeUri(String uri) {
        // Decode the path.
        try {
            uri = URLDecoder.decode(uri, "UTF-8");
        } catch (UnsupportedEncodingException e) {
            throw new Error(e);
        }
        if (uri.isEmpty() || uri.charAt(0) != '/') {
            return null;
        }
        // Convert file separators.
        uri = uri.replace('/', File.separatorChar);
        // Simplistic dumb security check.
        // You will have to do something serious in the production environment.
        if (uri.contains(File.separator + '.') || uri.contains('.' + File.separator) || uri.charAt(0) == '.'
        || uri.charAt(uri.length() - 1) == '.' || INSECURE_URI.matcher(uri).matches()) {
            return null;
        }
        // Convert to absolute path.
        return System.getProperty("user.dir") + File.separator + uri;
    }
    public final void sendList(ChannelHandlerContext ctx, File file) {
        FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK);
        response.headers().set(HttpHeaders.Names.CONTENT_TYPE, "text/html; charset=UTF-8");
        StringBuilder sb = new StringBuilder();
        String dirPath = file.getPath();
        sb.append("<!DOCTYPE html>\r\n");
        sb.append("<html><head><title>");
        sb.append(dirPath);
        sb.append("目录: ");
        sb.append("</title></head><body>\r\n");
        sb.append("");
        sb.append(dirPath).append("目录: ");
        sb.append("\r\n");
        sb.append("");
        sb.append("..\r\n");
        for (File f : file.listFiles()) {
            if (f.isHidden() || !f.canRead()) {
                continue;
            }
            String name = f.getName();
            if (!ALLOWED_FILE_NAME.matcher(name).matches()) {
                continue;
            }
            sb.append("<a href=\"");
            sb.append(name);
            sb.append("\">");
            sb.append(name);
            sb.append("\r\n");
        }
        sb.append("</body></html>\r\n");
        ByteBuf buffer = Unpooled.copiedBuffer(sb, CharsetUtil.UTF_8);
        response.content().writeBytes(buffer);
        buffer.release();
        // Close the connection as soon as the error message is sent.
        ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE);
    }
    public void sendRedirect(ChannelHandlerContext ctx, String newUri) {
        FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.FOUND);
        response.headers().set(HttpHeaders.Names.LOCATION, newUri);
        ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE);
    }
    private void setContentTypeHeader(HttpResponse response, File file) {
        MimetypesFileTypeMap mimeTypeMap = new MimetypesFileTypeMap();
        response.headers().set(HttpHeaders.Names.CONTENT_TYPE, mimeTypeMap.getContentType(file.getPath()));
    }
}