private void onEvent(final Connection conn, final String remoteAddress,
                         final ConnectionEventType type) {
        if (this.eventListener != null) {
            this.eventExecutor.onEvent(new Runnable() {
                @Override
                public void run() {
                    ConnectionEventHandler.this.eventListener.onEvent(type, remoteAddress, conn);
                }
            });
        }
    }
@see io.netty.channel.ChannelInboundHandlerAdapter#channelRegistered(io.netty.channel.ChannelHandlerContext)
src/main/java/com/alipay/remoting/ConnectionEventHandler.java