java.lang.NoClassDefFoundError: org/apache/flink/streaming/api/scala/StreamExecutionEnvironment - scala

Question

package com.knoldus
import org.apache.flink.api.java.utils.ParameterTool
import org.apache.flink.streaming.api.scala._
import org.apache.flink.streaming.api.windowing.time.Time
object SocketWindowWordCount {
def main(args: Array[String]) : Unit = {
var hostname: String = "localhost"
var port: Int = 9000
try {
val params = ParameterTool.fromArgs(args)
hostname = if (params.has("hostname")) params.get("hostname") else "localhost"
port = params.getInt("port")
} catch {
case e: Exception => {
System.err.println("No port specified. Please run 'SocketWindowWordCount " +
"--hostname <hostname> --port <port>', where hostname (localhost by default) and port " +
"is the address of the text server")
System.err.println("To start a simple text server, run 'netcat -l <port>' " +
"and type the input text into the command line")
return
}
}
// get the execution environment
val env: StreamExecutionEnvironment = StreamExecutionEnvironment.getExecutionEnvironment
// get input data by connecting to the socket
val text: DataStream[String] = env.socketTextStream(hostname, port, '\n')
// parse the data, group it, window it, and aggregate the counts
val windowCounts = text
.flatMap { w => w.split("\\s") }
.map { w => WordWithCount(w, 1) }
.keyBy("word")
.timeWindow(Time.seconds(5))
.sum("count")
// print the results with a single thread, rather than in parallel
windowCounts.print().setParallelism(1)
env.execute("Socket Window WordCount")
}
/** Data type for words with count */
case class WordWithCount(word: String, count: Long)
}
In the end while running this code on Intellij i am getting this error
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/flink/streaming/api/scala/StreamExecutionEnvironment$
at com.knoldus.SocketWindowWordCount$.main(SocketWindowWordCount.scala:43)
at com.knoldus.SocketWindowWordCount.main(SocketWindowWordCount.scala)
Caused by: java.lang.ClassNotFoundException: org.apache.flink.streaming.api.scala.StreamExecutionEnvironment$
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:581)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
... 2 more

Answer 1

Select menu item "Run" => "Edit Configurations...",
then in the "Build and run" section select "Modify options" => Java => Add dependencies with "Provided" scope to classpath in your local configuration.
In this way you don't have to remove the <scope>provided</scope>.

Answer 2

I resolved this by removing the <scope>provided</scope> which was present in the maven import.