系统中有自己的Netty服务器，同时指定Dubbo用Netty，然后LoggingHandler就没法用了。下面的代码回导致我的Netty服务器无法使用Netty自带的日志体系。如果我强制自己的Netty服务器晚于Dubbo加载，那么Dubbo也是无法使用到DubboLogger的。
```
public class NettyHelper {

    public static void setNettyLoggerFactory() {
        InternalLoggerFactory factory = InternalLoggerFactory.getDefaultFactory();
        if (factory == null || !(factory instanceof DubboLoggerFactory)) {
            InternalLoggerFactory.setDefaultFactory(new DubboLoggerFactory());
        }
    }
```
# Added content in English. Help with Google Translate
System is TCP server using Netty4, and Dubbo is specified to use Netty4. When I add LoggingHandler to ChannelPipeline of my System, The log is not expected. 
Like this:
![image](https://user-images.githubusercontent.com/11850956/37442060-5a02eabc-283f-11e8-939a-68255f8912b2.png)

I tracked the code and found the Logger is `com.alibaba.dubbo.remoting.transport.netty4.logging.NettyHelper.DubboLogger` instead of `io.netty.util.internal.logging.Slf4JLogger`.  DubboLogger added other content arount the original log. The NeetyHelper replace the InternalLoggerFactory when Dubbo loading, like the code block above shows.
# By the way.
My system build by Spring Boot, use default logging framework which is Slf4j + Logback.
Dubbo's logger is not extend default logger, but replace it.
![image](https://user-images.githubusercontent.com/11850956/37442386-0585c494-2841-11e8-8f8f-354e7f226726.png)

protected void doOpen() throws Throwable {
        NettyHelper.setNettyLoggerFactory();
        bootstrap = new ServerBootstrap();
        bossGroup = new NioEventLoopGroup(1, new DefaultThreadFactory("NettyServerBoss", true));
        workerGroup = new NioEventLoopGroup(getUrl().getPositiveParameter(Constants.IO_THREADS_KEY, Constants.DEFAULT_IO_THREADS),
                new DefaultThreadFactory("NettyServerWorker", true));
        final NettyServerHandler nettyServerHandler = new NettyServerHandler(getUrl(), this);
        channels = nettyServerHandler.getChannels();
        bootstrap.group(bossGroup, workerGroup)
                .channel(NioServerSocketChannel.class)
                .childOption(ChannelOption.TCP_NODELAY, Boolean.TRUE)
                .childOption(ChannelOption.SO_REUSEADDR, Boolean.TRUE)
                .childOption(ChannelOption.ALLOCATOR, PooledByteBufAllocator.DEFAULT)
                .childHandler(new ChannelInitializer<NioSocketChannel>() {
                    @Override
                    protected void initChannel(NioSocketChannel ch) throws Exception {
                        NettyCodecAdapter adapter = new NettyCodecAdapter(getCodec(), getUrl(), NettyServer.this);
                        ch.pipeline()
                                .addLast("decoder", adapter.getDecoder())
                                .addLast("encoder", adapter.getEncoder())
                                .addLast("handler", nettyServerHandler);
                    }
                });
        
        ChannelFuture channelFuture = bootstrap.bind(getBindAddress());
        channelFuture.syncUninterruptibly();
        channel = channelFuture.channel();
    }
    @Override
    protected void doClose() throws Throwable {