Exception in thread "main" java.lang.NoClassDefFoundError: io/netty/channel/EventLoopGroup

最近在学习dubbo，跟着教程做，但是运行时报错，需要添加netty依赖

<dependency>
             <groupId>io.netty</groupId>
            <artifactId>netty-all</artifactId>
            <version>4.1.32.Final</version>
        </dependency>