无法在Flink中运行wordcount示例

Question

在导入flink-release-1.4.2的pom之后，我尝试运行wordcount示例。但是由于Scala出现许多错误，所以我无法构建它。

 Information:19-2-20 上午2:45 - Compilation completed with 53 errors and 0 warnings in 2s 439ms
/media/maple/新加卷/download/Notes/flink-release-1.4.2/flink-examples/flink-examples-batch/src/main/scala/org/apache/flink/examples/scala/clustering/KMeans.scala
Error:(81, 14) not found: type ExecutionEnvironment
    val env: ExecutionEnvironment = ExecutionEnvironment.getExecutionEnvironment
Error:(81, 37) not found: value ExecutionEnvironment
    val env: ExecutionEnvironment = ExecutionEnvironment.getExecutionEnvironment
Error:(85, 17) not found: type DataSet
    val points: DataSet[Point] = getPointDataSet(params, env)
Error:(131, 74) not found: type DataSet
  def getPointDataSet(params: ParameterTool, env: ExecutionEnvironment): DataSet[Point] = {
Error:(131, 51) not found: type ExecutionEnvironment
  def getPointDataSet(params: ParameterTool, env: ExecutionEnvironment): DataSet[Point] = {
Error:(86, 20) not found: type DataSet
    val centroids: DataSet[Centroid] = getCentroidDataSet(params, env)

那是怎么回事。当我仅导入flink-examples的pom时，wordcount程序可以正常运行。例如：

我尝试重新导入Maven，使缓存无效并安装Scala插件。

Answer 1

使用IntelliJ，您将需要JetBrains Scala插件，并且需要打开项目结构对话框，并在“全局库”部分中添加Scala SDK。

Answer 2

问题已解决。我运行library(ggplot2) dat <- iris[c(1,2,51,52,101,102),] dat[1,"Species"] <- NA dat[["Species"]] <- factor(dat[["Species"]], levels = c("virginica", NA, "setosa", "versicolor"), exclude = NULL) dat[["Species"]] # [1] <NA> setosa versicolor versicolor virginica virginica # Levels: virginica <NA> setosa versicolor # NA is the second level ggplot(dat, aes(x=Species, y=Sepal.Width)) + geom_point() # NA appears at right 并成功重建。