如何在 Netty 客户端中使用 Socks4/5 代理处理程序 (4.1)

我需要在Netty客户端中配置socks代理（通过socks4或5代理请求不同的站点）。 尝试了很多免费袜子列表中的代理（例如 www.socks-proxy.net，http://sockslist.net/ http://sockslist.net/等）但没有运气：

@Test
public void testProxy() throws Exception {
    final String ua = "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2228.0 Safari/537.36";
    final String host = "www.main.de";
    final int port = 80;

    Bootstrap b = new Bootstrap();
    b.group(new NioEventLoopGroup())
            .channel(NioSocketChannel.class)
            .handler(new ChannelInitializer<SocketChannel>() {
                @Override
                protected void initChannel(SocketChannel ch) throws Exception {
                    ChannelPipeline p = ch.pipeline();

                    p.addLast(new HttpClientCodec());
                    p.addLast(new HttpContentDecompressor());
                    p.addLast(new HttpObjectAggregator(10_485_760));
                    p.addLast(new ChannelInboundHandlerAdapter() {
                        @Override
                        public void channelActive(final ChannelHandlerContext ctx) throws Exception {
                            HttpRequest request = new DefaultFullHttpRequest(HTTP_1_1, GET, "/");
                            request.headers().set(HOST, host + ":" + port);
                            request.headers().set(USER_AGENT, ua);
                            request.headers().set(CONNECTION, CLOSE);

                            ctx.writeAndFlush(request);

                            System.out.println("!sent");
                        }

                        @Override
                        public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
                            System.out.println("!answer");
                            if (msg instanceof FullHttpResponse) {
                                FullHttpResponse httpResp = (FullHttpResponse) msg;


                                ByteBuf content = httpResp.content();
                                String strContent = content.toString(UTF_8);
                                System.out.println("body: " + strContent);

                                finish.countDown();
                                return;
                            }

                            super.channelRead(ctx, msg);
                        }

                        @Override
                        public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
                            cause.printStackTrace(System.err);
                            ctx.close();
                            finish.countDown();
                        }
                    });

                    p.addLast(new Socks4ProxyHandler(new InetSocketAddress("149.202.68.167", 37678)));
                }
            });

    b.connect(host, port).awaitUninterruptibly();
    System.out.println("!connected");

    finish.await(1, MINUTES);
}

连接挂起、重置或出现一些奇怪的异常。 怎么了？ Netty从4.1开始增加了代理支持（现在有4.1CR，之前尝试过和4.1b7-8）

代理实例应该是管道中的第一个实例，因为您希望它在处理任何 http 内容之前首先处理与代理的连接。

要改变这一点，改变p.addLast(new Socks4ProxyHandler(new InetSocketAddress("149.202.68.167", 37678))); to:

p.addFirst(new Socks4ProxyHandler(new InetSocketAddress("149.202.68.167", 37678)));

正如文档中所解释的ChannelPipeline http://netty.io/4.0/api/io/netty/channel/ChannelPipeline.html，数据流从第一个处理程序开始，到最后一个处理程序结束。