Btukfyl

Client reconnects to server when connection is closed with Netty. But every time when connection is lost, client will reconnnect using two threads. Reconnection leads to double connections. How can I solve the problem?

public class ImConnection {

    private static Logger logger = LoggerFactory.getLogger(ImConnection.class);

    private static Bootstrap b;

    private Channel channel;



    static {

        b = new Bootstrap();

        EventLoopGroup workerGroup = new NioEventLoopGroup();

        b.group(workerGroup);

        b.channel(NioSocketChannel.class);

        b.option(ChannelOption.SO_KEEPALIVE, true);

        b.handler(new ConnectionInitializer());

    }



    public Channel connect() {

        doConnect(PropertyConstant.cfgcServerIP, PropertyConstant.cfgcServerPort);

        return this.channel;

    }

    private void doConnect(String host, int port) {

        try {

            ChannelFuture f = b.connect(host, port);

            f.addListener(new ChannelFutureListener() {

                @Override

                public void operationComplete(ChannelFuture future) throws Exception {

                    if (!future.isSuccess()) {

                        final EventLoop loop = future.channel().eventLoop();

                        loop.schedule(new Runnable() {

                            @Override

                            public void run() {

                                try {

                                    connect(); // reconnect if fail

                                } catch (Exception e) {

                                    e.printStackTrace();

                                }

                            }

                        }, 1L, TimeUnit.SECONDS);

                    } else {

                        logger.info("connected");

                    }

            }});

            channel = f.channel();

        } catch(Exception e) {

            e.printStackTrace();

        }

    }

}

handler initializer

public class ConnectionInitializer extends ChannelInitializer<Channel> {



    protected void initChannel(Channel ch) throws Exception {

        ChannelPipeline pipeline = ch.pipeline();

        pipeline.addLast(new ConnectionHandler());

    }

}

handler to reconnect when connection is lost

public class ConnectionHandler extends ChannelInboundHandlerAdapter {

    private ImConnection imConnection = new ImConnection();



    // get executed when connection drops

    @Override

    public void channelInactive(ChannelHandlerContext ctx) throws Exception {

        System.err.println("connection lost");

        final EventLoop eventLoop = ctx.channel().eventLoop();

        eventLoop.schedule(new Runnable() {

            @Override

            public void run() {

                imConnection.connect();

            }

        }, 1L, TimeUnit.SECONDS);

        super.channelInactive(ctx);

    }

}