io.netty.util.concurrent.SingleThreadEventExecutor.<init>(Lio/netty/util/concurrent/EventExecutorGroup;Ljava/util/concurrent/Executor;ZLjava/util/Queue;Lio/netty/util/concurrent/RejectedExecutionHandler;)V

netty版本冲突，我们在idea的Terminal执行  mvn dependency:tree

然后在结果中搜索有冲突的io.netty，确定是那些引用后，我们修改pom文件相应引用的依赖配置，排除即可

    <dependency>
            <exclusions>
                <exclusion>
                    <groupId>com.google.code.gson</groupId>
                    <artifactId>gson</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.jboss.netty</groupId>
                    <artifactId>netty</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>io.netty</groupId>
                    <artifactId>netty</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>io.netty</groupId>
                    <artifactId>netty-all</artifactId>
                </exclusion>
            </exclusions>
            <groupId>org.apache.spark</groupId>
            <artifactId>spark-sql_2.12</artifactId>
            <version>${spark.version}</version>
    </dependency>