Exception in thread "main" java.lang.NoClassDefFoundError: Could not initialize class io.netty.util.internal.PlatformDependent0
at io.netty.util.internal.PlatformDependent.getSystemClassLoader(PlatformDependent.java:694)
at io.netty.channel.nio.NioEventLoop$4.run(NioEventLoop.java:171)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:318)
at io.netty.channel.nio.NioEventLoop.openSelector(NioEventLoop.java:167)
at io.netty.channel.nio.NioEventLoop.<init>(NioEventLoop.java:149)
at io.netty.channel.nio.NioEventLoopGroup.newChild(NioEventLoopGroup.java:102)
at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:64)
at io.netty.channel.MultithreadEventLoopGroup.<init>(MultithreadEventLoopGroup.java:49)
at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:70)
at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:65)
at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:56)
at org.apache.spark.network.util.NettyUtils.createEventLoop(NettyUtils.java:51)
at org.apache.spark.network.client.TransportClientFactory.<init>(TransportClientFactory.java:103)
at org.apache.spark.network.TransportContext.createClientFactory(TransportContext.java:99)
at org.apache.spark.rpc.netty.NettyRpcEnv.<init>(NettyRpcEnv.scala:70)
at org.apache.spark.rpc.netty.NettyRpcEnvFactory.create(NettyRpcEnv.scala:442)
at org.apache.spark.rpc.RpcEnv$.create(RpcEnv.scala:56)
at org.apache.spark.SparkEnv$.create(SparkEnv.scala:245)
at org.apache.spark.SparkEnv$.createDriverEnv(SparkEnv.scala:174)
at org.apache.spark.SparkContext.createSparkEnv(SparkContext.scala:257)
at org.apache.spark.SparkContext.<init>(SparkContext.scala:432)
at org.apache.spark.SparkContext$.getOrCreate(SparkContext.scala:2320)
at org.apache.spark.sql.SparkSession$Builder$$anonfun$6.apply(SparkSession.scala:868)
at org.apache.spark.sql.SparkSession$Builder$$anonfun$6.apply(SparkSession.scala:860)
at scala.Option.getOrElse(Option.scala:121)
at org.apache.spark.sql.SparkSession$Builder.getOrCreate(SparkSession.scala:860)
at com.atguigu.content.ContentRecommender$.main(ContentRecommender.scala:48)
at com.atguigu.content.ContentRecommender.main(ContentRecommender.scala)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:568)
at com.intellij.rt.execution.application.AppMainV2.main(AppMainV2.java:128)
```
