3. scala-spark wordCount 案例
阿新 • • 發佈:2020-10-08
1. 建立maven 工程
2. 相關依賴和外掛
<dependencies> <dependency> <groupId>org.apache.spark</groupId> <artifactId>spark-core_2.11</artifactId> <version>2.1.1</version> </dependency> </dependencies> <build> <finalName>wordCount</finalName> <plugins> <plugin> <groupId>net.alchim31.maven</groupId> <artifactId>scala-maven-plugin</artifactId> <version>4.2.0</version><executions> <execution> <goals> <goal>compile</goal> <goal>testCompile</goal> </goals> </execution> </executions> </plugin> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-assembly-plugin</artifactId> <version>3.1.0</version><configuration> <archive> <manifest> <mainClass>wordCount</mainClass> </manifest> </archive> <descriptorRefs> <descriptorRef>jar-with-dependencies</descriptorRef> </descriptorRefs> </configuration> <executions> <execution> <id>make-assembly</id> <phase>package</phase> <goals> <goal>single</goal> </goals> </execution> </executions> </plugin> </plugins> </build>
3. wordCount 案例
package com.atgu.bigdata.spark import org.apache.spark._ import org.apache.spark.rdd.RDD object wordCount extends App { // local模式 // 1.建立sparkConf 物件 val conf: SparkConf = new SparkConf().setMaster("local[*]").setAppName("wordCount") // 2. 建立spark 上下文物件 val sc:SparkContext=new SparkContext(config = conf) // 3. 讀取檔案 val lines: RDD[String] = sc.textFile("file:///opt/data/1.txt") // 4. 切割單詞 val words: RDD[String] = lines.flatMap(_.split(" ")) // words.collect().foreach(println) // map private val keycounts: RDD[(String, Int)] = words.map((_, 1)) // private val results: RDD[(String, Int)] = keycounts.reduceByKey(_ + _) private val res: Array[(String, Int)] = results.collect res.foreach(println) }