rocketmq源码解析之NamesrvController启动②创建mqclient②

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源码解析
netty连接管理handler

 class NettyConnectManageHandler extends ChannelDuplexHandler {
        @Override
        public void connect(ChannelHandlerContext ctx, SocketAddress remoteAddress, SocketAddress localAddress,
            ChannelPromise promise) throws Exception {
            final String local = localAddress == null ? "UNKNOWN" : RemotingHelper.parseSocketAddressAddr(localAddress);
            final String remote = remoteAddress == null ? "UNKNOWN" : RemotingHelper.parseSocketAddressAddr(remoteAddress);
            log.info("NETTY CLIENT PIPELINE: CONNECT  {} => {}", local, remote);
//            创建netty连接
            super.connect(ctx, remoteAddress, localAddress, promise);
            if (NettyRemotingClient.this.channelEventListener != null) {
//                发布netty事件，阻塞队列实现同步=》
                NettyRemotingClient.this.putNettyEvent(new NettyEvent(NettyEventType.CONNECT, remote, ctx.channel()));
            }
        }

        @Override
        public void disconnect(ChannelHandlerContext ctx, ChannelPromise promise) throws Exception {
            final String remoteAddress = RemotingHelper.parseChannelRemoteAddr(ctx.channel());
            log.info("NETTY CLIENT PIPELINE: DISCONNECT {}", remoteAddress);
//            关闭连接=》
            closeChannel(ctx.channel());
            super.disconnect(ctx, promise);
            if (NettyRemotingClient.this.channelEventListener != null) {
//                发布关闭连接事件=》
                NettyRemotingClient.this.putNettyEvent(new NettyEvent(NettyEventType.CLOSE, remoteAddress, ctx.channel()));
            }
        }

        @Override
        public void close(ChannelHandlerContext ctx, ChannelPromise promise) throws Exception {
            final String remoteAddress = RemotingHelper.parseChannelRemoteAddr(ctx.channel());
            log.info("NETTY CLIENT PIPELINE: CLOSE {}", remoteAddress);
//            =》
            closeChannel(ctx.channel());
            super.close(ctx, promise);
//            快速失败=》
            NettyRemotingClient.this.failFast(ctx.channel());
            if (NettyRemotingClient.this.channelEventListener != null) {
//                发布连接关闭事件
                NettyRemotingClient.this.putNettyEvent(new NettyEvent(NettyEventType.CLOSE, remoteAddress, ctx.channel()));
            }
        }

        @Override
        public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
            if (evt instanceof IdleStateEvent) {
                IdleStateEvent event = (IdleStateEvent) evt;
                if (event.state().equals(IdleState.ALL_IDLE)) {
                    final String remoteAddress = RemotingHelper.parseChannelRemoteAddr(ctx.channel());
                    log.warn("NETTY CLIENT PIPELINE: IDLE exception [{}]", remoteAddress);
//                    超过空闲时间，关闭channel=》
                    closeChannel(ctx.channel());
                    if (NettyRemotingClient.this.channelEventListener != nu