嗨，我正在使用具有等技术的playframework
spark = "2.3.1",
akka = "2.4.7"
hadoop = "2.7.7"
spring = "4.2.6.RELEASE",
spark-cassandra-connector 2.0.9 ,
cassandra-driver-core 3.0.6
我收到以下警告，在项目清理编译时
c.d.d.c.NettyUtil - Found Netty's native epoll transport, but not running on linux-based operating system. Using NIO instead
io.netty:netty-handler:4.0.56.Final is selected over 4.0.36.Final
+- com.datastax.cassandra:cassandra-driver-core:3.5.1 (depends on 4.0.56.Final)
+- com.typesafe.netty:netty-reactive-streams:1.0.6 (depends on 4.0.36.Final)
+- io.netty:netty-codec-http:4.0.36.Final (depends on 4.0.36.Final)
在sbt运行时，低于错误
java.lang.NullPointerException
at io.netty.channel.group.DefaultChannelGroup.add(DefaultChannelGroup.java:146)
at play.core.server.NettyServer.bind(NettyServer.scala:140)
at play.core.server.NettyServer.play$core$server$NettyServer$$bindChannel(NettyServer.scala:224)
at play.core.server.NettyServer$$anonfun$1.apply(NettyServer.scala:216)
at play.core.server.NettyServer$$anonfun$1.apply(NettyServer.scala:216)
at scala.Option.map(Option.scala:146)
at play.core.server.NettyServer.<init>(NettyServer.scala:216)
at play.core.server.NettyServerProvider.createServer(NettyServer.scala:279)
at play.core.server.NettyServerProvider.createServer(NettyServer.scala:278)
at play.core.server.DevServerStart$$anonfun$mainDev$1.apply(DevServerStart.scala:225)
at play.core.server.DevServerStart$$anonfun$mainDev$1.apply(DevServerStart.scala:61)
at play.utils.Threads$.withContextClassLoader(Threads.scala:21)
at play.core.server.DevServerStart$.mainDev(DevServerStart.scala:60)
at play.core.server.DevServerStart$.mainDevHttpMode(DevServerStart.scala:50)
at play.core.server.DevServerStart.mainDevHttpMode(DevServerStart.scala)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at play.runsupport.Reloader$.startDevMode(Reloader.scala:234)
at play.sbt.run.PlayRun$$anonfun$playRunTask$1$$anonfun$apply$2$$anonfun$apply$3.devModeServer$lzycompute$1(PlayRun.scala:74)
at play.sbt.run.PlayRun$$anonfun$playRunTask$1$$anonfun$apply$2$$anonfun$apply$3.play$sbt$run$PlayRun$$anonfun$$anonfun$$anonfun$$devModeServer$1(PlayRun.scala:74)
at play.sbt.run.PlayRun$$anonfun$playRunTask$1$$anonfun$apply$2$$anonfun$apply$3.apply(PlayRun.scala:100)
at play.sbt.run.PlayRun$$anonfun$playRunTask$1$$anonfun$apply$2$$anonfun$apply$3.apply(PlayRun.scala:53)
at scala.Function1$$anonfun$compose$1.apply(Function1.scala:47)
at sbt.$tilde$greater$$anonfun$$u2219$1.apply(TypeFunctions.scala:40)
at sbt.std.Transform$$anon$4.work(System.scala:63)
at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:228)
at sbt.Execute$$anonfun$submit$1$$anonfun$apply$1.apply(Execute.scala:228)
at sbt.ErrorHandling$.wideConvert(ErrorHandling.scala:17)
at sbt.Execute.work(Execute.scala:237)
at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:228)
at sbt.Execute$$anonfun$submit$1.apply(Execute.scala:228)
at sbt.ConcurrentRestrictions$$anon$4$$anonfun$1.apply(ConcurrentRestrictions.scala:159)
at sbt.CompletionService$$anon$2.call(CompletionService.scala:28)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
[error] (*:playRun) java.lang.reflect.InvocationTargetException
如何解决棘手的问题？是否存在版本不匹配的问题？？
这个问题与Cassandra有关，所以目前，我使用了Cassandra的着色版本。出现问题是因为应用程序使用了另一个netty版本，所以为了避免这种冲突，提供了cassandra的阴影版本jar，它将netty类捆绑在不同的包下
"com.datastax.cassandra"%"cassandra驱动程序核心"%"3.1.4"排除("io.netty"，"*"(分类器"阴影">
参考：https://docs.datastax.com/en/developer/java-driver/3.1/manual/shaded_jar/
此外，您还可以使用dependencyOverrides:
要更改所选版本，请添加覆盖：
dependencyOverrides+="%"%">
参考：https://www.scala-sbt.org/1.x/docs/Library-Management.html#Overriding+a+版本
如果您在这里也提供一些代码(尤其是初始化netty的代码(，我会更有帮助，但您面临的问题是在非Linux系统中使用Linux本机传输。试着找到使用Epoll的地方，并用所有操作系统都支持的NIO替换它们。如果你也在Linux上运行你的应用程序，那么你应该检查你是否可以将Epoll.isAvailable((与Epoll一起使用