Spark入門WordCount案例(Java和scala實現)

import org.apache.spark.SparkConf;
import org.apache.spark.SparkContext;
import org.apache.spark.api.java.JavaPairRDD;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.JavaSparkContext;
import org.apache.spark.api.java.function.FlatMapFunction;
import org.apache.spark.api.java.function.FlatMapFunction2;
import org.apache.spark.api.java.function.Function2;
import org.apache.spark.api.java.function.PairFunction;
import org.apache.spark.rdd.RDD;
import scala.Function1;
import scala.Tuple2;
import scala.collection.TraversableOnce;

import java.util.Arrays;
import java.util.Iterator;
import java.util.List;

public class WordCount1 {

    public static void main(String[] args) {
        // 配置spark任務,設置使用本地線程數爲4個
        SparkConf conf = new SparkConf().setMaster("local[4]").setAppName("wordCount");
        
        // 獲取context對象
        JavaSparkContext sc = new JavaSparkContext(conf);
        
        // 讀取文件
        JavaRDD<String> file = sc.textFile("./data/data");

//        JavaRDD<String> rdd = file.flatMap(new FlatMapFunction<String, String>() {
//            @Override
//            public Iterator<String> call(String s) throws Exception {
//                String[] s1 = s.split(" ");
//                Iterator<String> iterator = Arrays.asList(s1).iterator();
//
//                return iterator;
//            }
//        });

        JavaRDD<String> rdd = file.flatMap((String s) -> Arrays.asList(s.split(" ")).iterator());

        JavaPairRDD<String, Integer> rdd1 = rdd.mapToPair((String s) -> new Tuple2<String, Integer>(s, 1));

        JavaPairRDD<String, Integer> rdd2 = rdd1.reduceByKey((Integer v1, Integer v2) -> v1 + v2);

        List<Tuple2<String, Integer>> collect = rdd2.collect();

        for (Tuple2<String, Integer> res : collect) {
            System.out.println(res);
        }

        sc.stop();

    }
}

import org.apache.spark.{SparkConf, SparkContext}

object WordCount {
    def main(args: Array[String]): Unit = {
        // 創建SparkContext
        val conf = new SparkConf().setMaster("local[4]").setAppName("test")

        val sc = new SparkContext(conf)

        val res = sc.textFile("./data/data")

        val res1 = res.flatMap(_.split(" "))


        val res2 = res1.map(_ -> 1)

        val res3 = res2.reduceByKey(_ + _)

        res3.foreach(println)

        sc.stop()
    }
}

    <properties>
        <scala.version>2.11.8</scala.version>
        <spark.version>2.2.0</spark.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.scala-lang</groupId>
            <artifactId>scala-library</artifactId>
            <version>${scala.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.spark</groupId>
            <artifactId>spark-core_2.11</artifactId>
            <version>${spark.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-client</artifactId>
            <version>2.7.5</version>
        </dependency>
    </dependencies>
    <build>
        <sourceDirectory>src/main/scala</sourceDirectory>
        <testSourceDirectory>src/test/scala</testSourceDirectory>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.0</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                    <!--    <verbal>true</verbal>-->
                </configuration>
            </plugin>
            <plugin>
                <groupId>net.alchim31.maven</groupId>
                <artifactId>scala-maven-plugin</artifactId>
                <version>3.2.0</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>compile</goal>
                            <goal>testCompile</goal>
                        </goals>
                        <configuration>
                            <args>
                                <arg>-dependencyfile</arg>
                                <arg>${project.build.directory}/.scala_dependencies</arg>
                            </args>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
                <version>3.1.1</version>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>shade</goal>
                        </goals>
                        <configuration>
                            <filters>
                                <filter>
                                    <artifact>*:*</artifact>
                                    <excludes>
                                        <exclude>META-INF/*.SF</exclude>
                                        <exclude>META-INF/*.DSA</exclude>
                                        <exclude>META-INF/*.RSA</exclude>
                                    </excludes>
                                </filter>
                            </filters>
                            <transformers>
                                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                    <mainClass></mainClass>
                                </transformer>
                            </transformers>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>