本文处理的场景如下,hive表中的数据,对其中的多列进行判重deduplicate。...1、先解决依赖,spark相关的所有包,pom.xml spark-hive是我们进行hive表spark处理的关键。...; import org.apache.spark.api.java.function.Function2...
("hello scala", 3), ("hello spark from scala", 1), ("hello flink from scala", 2) ) // first split based on the input frequency val preCountList: List[(String, Int)] = tupleList.flatMap( tuple => { val strings: Array[String] = tuple._1.split(" ") strings.map(word => (...
Scala Tutorials Here atallaboutscala.com, we provide a complete beginner's tutorial to help you learn Scala insmall,simpleandeasysteps. We are an official learning resource for Scala: http://docs.scala-lang.org/learn.html GET OUR BOOKS: - Scala For Beginners This book provides astep-by-st...
"hello spark from scala", "hello flink from scala" ) // 1. 对字符串进行切分,得到一个打散所有单词的列表 val wordList = stringList.flatMap(_.split(" ")) println(wordList) // 2. 相同的单词进行分组 val groupMap: Map[String, List...
scala 处理嵌套的Json结构+---
Spark之中map与flatMap的区别 。flatMap的操作是将函数应用于rdd之中的每一个元素,将返回的迭代器的所有内容构成新的rdd。通常用来切分单词。区别1:flatMap返回的是迭代器中的元素。上面的例子说明对于传递给flatMap的...函数会对每一条输入进行指定的操作,然后为每一条输入返回一个对象;而flatMap函数则是两个操...
...Int] = Map(hadoop -> 5, spark -> 6, hbase -> 7) scala> books.get("hadoop") res0: Option[Int] = Some(...5) scala> books.get("hive") res1: Option[Int] = None scala> books.get("hive").getOrElse("No such book...") // 不存在的元素则使用其默认的值 res2: Any ...
enumerationDemo.values filter(_.toString.endsWith("Terrier")) foreach println } } 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 输出结果: 1:Yorkshire Terrier 2:Scottish Terrier 3:Great Dane 4:Portuguese Water Dog ...
spark由scala编写,要解析scala,首先要对scala有基本的了解。 1.1 class vs object A class is a blueprint for objects. Once you define a class, you can create objects from the class blueprint with the keywordnew. importjava.io._classPoint(val xc: Int, val yc: Int) { ...
(1)建议将该插件scala-intellij-bin-2017.2.6.zip文件,放到Scala的安装目录E:\02_software\scala-2.11.8下,方便管理。 (2)打开IDEA,在左上角找到File->在下拉菜单中点击Setting... ->点击Plugins->点击右下角Install plugin from disk…,找到插件存储路径E:\02_software\scala-2.11.8\scala-intellij-bin-201...