netty实战二之HTTP服务端开发

Netty http服务端

文件读取服务

HttpFileServerHandler.class

public class HttpFileServerHandler extends SimpleChannelInboundHandler {

    private static final Pattern INSECURE_URL = Pattern.compile(".*[<>&\"].*");
    private static final Pattern ALLOWED_FILE_NAME = Pattern.compile("[A-Za-z0-9][-_A-Za-z0-9\\.]*");
    private final String url;

    public HttpFileServerHandler(String url) {
        this.url = url;
    }

    private static void sendListing(ChannelHandlerContext ctx, File dir) {
        FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK);
        response.headers().set(HttpHeaderNames.CONTENT_TYPE, "text/html;charset=UTF-8");
        StringBuilder buf = new StringBuilder();
        String dirPath = dir.getPath();
        buf.append("\r\n");
        buf.append("\r\n");
        buf.append("
");
        buf.append(dirPath).append("目录:");
        buf.append("
\r\n");
        buf.append("
");
        buf.append("
链接：..
\r\n");
        for (File f : dir.listFiles()) {
            if (f.isHidden() || !f.canRead()) {
                continue;
            }
            String name = f.getName();
            if (!ALLOWED_FILE_NAME.matcher(name).matches()) {
                continue;
            }
            buf.append("
链接：");
            buf.append(name);
            buf.append("
\r\n");
        }
        buf.append("
\r\n");
        ByteBuf byteBuf = Unpooled.copiedBuffer(buf, CharsetUtil.UTF_8);
        response.content().writeBytes(byteBuf);
        byteBuf.release();
        ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE);
    }

    private static void sendRedirect(ChannelHandlerContext ctx, String newUrl) {
        FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.FOUND);
        response.headers().set(HttpHeaderNames.LOCATION, newUrl);
        ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE);
    }

    private static void sendError(ChannelHandlerContext ctx, HttpResponseStatus status) {
        FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, status, Unpooled.copiedBuffer("Failure:" + status.toString() + "\r\n", CharsetUtil.UTF_8));
        response.headers().set(HttpHeaderNames.CONTENT_TYPE, "text/plain;charset=UTF-8");
        ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE);
    }

    private static void setContentTypeHeader(HttpResponse response, File file) {
        MimetypesFileTypeMap mimetypesFileTypeMap = new MimetypesFileTypeMap();
        response.headers().set(HttpHeaderNames.CONTENT_TYPE, mimetypesFileTypeMap.getContentType(file.getPath()));
    }

    public static void main(String[] args) {
        HttpFileServerHandler handler = new HttpFileServerHandler("/netty/src/main/java/com/oneapm/netty/");
        System.out.println(handler.sanitizeUri("/netty/src/main/java/com/oneapm/netty/"));
    }

    @Override
    protected void channelRead0(ChannelHandlerContext ctx, FullHttpRequest msg) throws Exception {
        if (!msg.decoderResult().isSuccess()) {
            sendError(ctx, HttpResponseStatus.BAD_REQUEST);
            return;
        }
        if (msg.method() != HttpMethod.GET) {
            sendError(ctx, HttpResponseStatus.METHOD_NOT_ALLOWED);
            return;
        }
        final String uri = msg.uri();
        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("/")) {
                sendListing(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.NOT_FOUND);
            return;
        }
        long fileLength = randomAccessFile.length();
        HttpResponse response = new DefaultHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK);
        HttpUtil.setContentLength(response, fileLength);
        setContentTypeHeader(response, file);
        if (HttpUtil.isKeepAlive(msg)) {
            response.headers().set(HttpHeaderNames.CONNECTION, HttpHeaderValues.KEEP_ALIVE);
        }
        ctx.write(response);
        ChannelFuture sendFileFeture = ctx.write(new ChunkedFile(randomAccessFile, 0, fileLength, 8192), ctx.newProgressivePromise());
        sendFileFeture.addListener(new ChannelProgressiveFutureListener() {
            @Override
            public void operationProgressed(ChannelProgressiveFuture future, long progress, long total) throws Exception {
                if (total < 0) {
                    System.err.println("Transfer progress:" + progress);
                } else {
                    System.err.println("Transfer progress:" + progress + "/" + total);
                }
            }

            @Override
            public void operationComplete(ChannelProgressiveFuture future) throws Exception {
                System.out.println("Transfer complete!");
            }
        });
        ChannelFuture lastContentFuture = ctx.writeAndFlush(LastHttpContent.EMPTY_LAST_CONTENT);

        if (HttpUtil.isKeepAlive(msg)) {
            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 String sanitizeUri(String uri) {
        try {
            uri = URLDecoder.decode(uri, "UTF-8");
        } catch (UnsupportedEncodingException e) {
            try {
                uri = URLDecoder.decode(uri, "ISO-8859-1");
            } catch (UnsupportedEncodingException e1) {
                throw new Error();
            }
        }
        if (!uri.startsWith(url)) {
            return null;
        }

        if (!uri.startsWith("/")) {
            return null;
        }

        uri = uri.replace('/', File.separatorChar);
        if (uri.contains(File.separator + '.') || uri.contains('.' + File.separator) ||
                uri.startsWith(".") || uri.endsWith(".") || INSECURE_URL.matcher(uri).matches()) {
            return null;
        }

        return System.getProperty("user.dir") + uri;
    }

}

HttpFileServer.class

public class HttpFileServer {
    private static final String DEFAULT_URL = "/netty/src/main/java/com/oneapm/netty/";

    public static void main(String[] args) throws Exception {
        int port = 8080;
        if (args.length > 0) {
            try {
                port = Integer.parseInt(args[0]);
            } catch (NumberFormatException e) {
                e.printStackTrace();
            }
        }
        String url = DEFAULT_URL;
        if (args.length > 1)
            url = args[1];
        new HttpFileServer().run(port, url);
    }

    public void run(final int port, final String url) throws InterruptedException {
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap bootstrap = new ServerBootstrap();
            bootstrap.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class).childHandler(new ChannelInitializer() {
                @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 future = bootstrap.bind("localhost", port).sync();
            System.out.println("HTTP文件目录服务器启动，网址是 : " + "http://localhost:"
                    + port + url);
            future.channel().closeFuture().sync();
        } finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }
}

运行效果

http服务端文件传输

github地址

https://github.com/engimatic/effectivejava/tree/master/netty/src/main/java/com/oneapm/netty/http