3. scala-spark wordCount 案例

1. 创建maven 工程

2. 相关依赖和插件

<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.创建sparkConf 对象
   val conf: SparkConf = new SparkConf().setMaster("local[*]").setAppName("wordCount")
  // 2. 创建spark 上下文对象
  val sc:SparkContext=new SparkContext(config = conf)
  // 3. 读取文件
 val lines: RDD[String] = sc.textFile("file:///opt/data/1.txt")
  // 4. 切割单词
  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)

}

 4. 项目目录结构