本篇部落格,Alice為大家帶來關于如何在IDEA上編寫Spark程式的教程。

寫在前面
本次講解我會通過一個非常經典的案例,同時也是在學MapReduce入門時少不了的一個例子——WordCount 來完成不同場景下Spark程式代碼的書寫。大家可以在敲代碼時可以思考這樣一個問題,用Spark是不是真的比MapReduce簡便?
準備材料
wordcount.txt
hello me you her
hello you her
hello her
hello
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圖解WordCount
pom.xml
- 建立Maven項目并補全目錄、配置pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.czxy</groupId>
<artifactId>spark_demo</artifactId>
<version>1.0-SNAPSHOT</version>
<!-- 指定倉庫位置,依次為aliyun、cloudera和jboss倉庫 -->
<repositories>
<repository>
<id>aliyun</id>
<url>http://maven.aliyun.com/nexus/content/groups/public/</url>
</repository>
<repository>
<id>cloudera</id>
<url>https://repository.cloudera.com/artifactory/cloudera-repos/</url>
</repository>
<repository>
<id>jboss</id>
<url>http://repository.jboss.com/nexus/content/groups/public</url>
</repository>
</repositories>
<properties>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
<encoding>UTF-8</encoding>
<scala.version>2.11.8</scala.version>
<scala.compat.version>2.11</scala.compat.version>
<hadoop.version>2.7.4</hadoop.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.spark</groupId>
<artifactId>spark-sql_2.11</artifactId>
<version>${spark.version}</version>
</dependency>
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-hive_2.11</artifactId>
<version>${spark.version}</version>
</dependency>
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-hive-thriftserver_2.11</artifactId>
<version>${spark.version}</version>
</dependency>
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-streaming_2.11</artifactId>
<version>${spark.version}</version>
</dependency>
<!-- <dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-streaming-kafka-0-8_2.11</artifactId>
<version>${spark.version}</version>
</dependency>-->
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-streaming-kafka-0-10_2.11</artifactId>
<version>${spark.version}</version>
</dependency>
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-sql-kafka-0-10_2.11</artifactId>
<version>${spark.version}</version>
</dependency>
<!--<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-client</artifactId>
<version>2.6.0-mr1-cdh5.14.0</version>
</dependency>
<dependency>
<groupId>org.apache.hbase</groupId>
<artifactId>hbase-client</artifactId>
<version>1.2.0-cdh5.14.0</version>
</dependency>
<dependency>
<groupId>org.apache.hbase</groupId>
<artifactId>hbase-server</artifactId>
<version>1.2.0-cdh5.14.0</version>
</dependency>-->
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-client</artifactId>
<version>2.7.4</version>
</dependency>
<dependency>
<groupId>org.apache.hbase</groupId>
<artifactId>hbase-client</artifactId>
<version>1.3.1</version>
</dependency>
<dependency>
<groupId>org.apache.hbase</groupId>
<artifactId>hbase-server</artifactId>
<version>1.3.1</version>
</dependency>
<dependency>
<groupId>com.typesafe</groupId>
<artifactId>config</artifactId>
<version>1.3.3</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.38</version>
</dependency>
</dependencies>
<build>
<sourceDirectory>src/main/java</sourceDirectory>
<testSourceDirectory>src/test/scala</testSourceDirectory>
<plugins>
<!-- 指定編譯java的插件 -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.5.1</version>
</plugin>
<!-- 指定編譯scala的插件 -->
<plugin>
<groupId>net.alchim31.maven</groupId>
<artifactId>scala-maven-plugin</artifactId>
<version>3.2.2</version>
<executions>
<execution>
<goals>
<goal>compile</goal>
<goal>testCompile</goal>
</goals>
<configuration>
<args>
<arg>-dependencyfile</arg>
<arg>${project.build.directory}/.scala_dependencies</arg>
</args>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.18.1</version>
<configuration>
<useFile>false</useFile>
<disableXmlReport>true</disableXmlReport>
<includes>
<include>**/*Test.*</include>
<include>**/*Suite.*</include>
</includes>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<version>2.3</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>
</project>
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- maven-assembly-plugin和maven-shade-plugin的差別
可以參考這篇部落格https://blog.csdn.net/lisheng19870305/article/details/88300951
本地執行
package com.czxy.scala
import org.apache.spark.rdd.RDD
import org.apache.spark.{SparkConf, SparkContext}
/*
* @Auther: Alice菌
* @Date: 2020/2/19 08:39
* @Description:
流年笑擲 未來可期。以夢為馬,不負韶華!
*/
/**
* 本地運作
*/
object Spark_wordcount {
def main(args: Array[String]): Unit = {
// 1.建立SparkContext
var config = new SparkConf().setAppName("wc").setMaster("local[*]")
val sc = new SparkContext(config)
sc.setLogLevel("WARN")
// 2.讀取檔案
// A Resilient Distributed Dataset (RDD)彈性分布式資料集
// 可以簡單了解為分布式的集合,但是Spark對它做了很多的封裝
// 讓程式員使用起來就像操作本地集合一樣簡單,這樣大家就很happy了
val fileRDD: RDD[String] = sc.textFile("G:\\2020幹貨\\Spark\\wordcount.txt")
// 3.處理資料
// 3.1 對每一行資料按空格切分并壓平形成一個新的集合中
// flatMap是對集合中的每一個元素進行操作,再進行壓平
val wordRDD: RDD[String] = fileRDD.flatMap(_.split(" "))
// 3.2 每個單詞記為1
val wordAndOneRDD: RDD[(String, Int)] = wordRDD.map((_,1))
// 3.3 根據key進行聚合,統計每個單詞的數量
// wordAndOneRDD.reduceByKey((a,b)=>a+b)
// 第一個_: 之前累加的結果
// 第二個_: 目前進來的資料
val wordAndCount: RDD[(String, Int)] = wordAndOneRDD.reduceByKey(_+_)
// 4. 收集結果
val result: Array[(String, Int)] = wordAndCount.collect()
// 控制台列印結果
result.foreach(println)
}
}
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運作的結果:
叢集上運作
package com.czxy.scala
import org.apache.spark.rdd.RDD
import org.apache.spark.{SparkConf, SparkContext}
/*
* @Auther: Alice菌
* @Date: 2020/2/19 09:12
* @Description:
流年笑擲 未來可期。以夢為馬,不負韶華!
*/
/**
* 叢集運作
*/
object Spark_wordcount_cluster {
def main(args: Array[String]): Unit = {
// 1. 建立SparkContext
val config = new SparkConf().setAppName("wc")
val sc = new SparkContext(config)
sc.setLogLevel("WARN")
// 2. 讀取檔案
// A Resilient Distributed Dataset (RDD) 彈性分布式資料集
// 可以簡單了解為分布式的集合,但是spark對它做了很多的封裝
// 讓程式員使用起來就像操作本地集合一樣簡單,這樣大家就很happy了
val fileRDD: RDD[String] = sc.textFile(args(0)) // 檔案輸入路徑
// 3. 處理資料
// 3.1對每一行資料按照空格進行切分并壓平形成一個新的集合
// flatMap是對集合中的每一個元素進行操作,再進行壓平
val wordRDD: RDD[String] = fileRDD.flatMap(_.split(" "))
// 3.2 每個單詞記為1
val wordAndOneRDD = wordRDD.map((_,1))
// 3.3 根據key進行聚合,統計每個單詞的數量
// wordAndOneRDD.reduceByKey((a,b)=>a+b)
// 第一個_:之前累加的結果
// 第二個_:目前進來的資料
val wordAndCount: RDD[(String, Int)] = wordAndOneRDD.reduceByKey(_+_)
wordAndCount.saveAsTextFile(args(1)) // 檔案輸出路徑
}
}
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- 打包
- 上傳
- 執行指令送出到Spark-HA叢集
/export/servers/spark/bin/spark-submit \
--class cn.itcast.sparkhello.WordCount \
--master spark://node01:7077,node02:7077 \
--executor-memory 1g \
--total-executor-cores 2 \
/root/wc.jar \
hdfs://node01:8020/wordcount/input/words.txt \
hdfs://node01:8020/wordcount/output4
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- 執行指令送出到YARN叢集
/export/servers/spark/bin/spark-submit \
--class cn.itcast.sparkhello.WordCount \
--master yarn \
--deploy-mode cluster \
--driver-memory 1g \
--executor-memory 1g \
--executor-cores 2 \
--queue default \
/root/wc.jar \
hdfs://node01:8020/wordcount/input/words.txt \
hdfs://node01:8020/wordcount/output5
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這裡我們送出到YARN叢集
運作結束後在hue中檢視結果
Java8版[了解]
Spark是用Scala實作的,而scala作為基于JVM的語言,與Java有着良好內建關系。用Java語言來寫前面的案例同樣非常簡單,隻不過會有點冗長。
package com.czxy.scala;
import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaPairRDD;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.JavaSparkContext;
import scala.Tuple2;
import java.util.Arrays;
/**
* @Auther: Alice菌
* @Date: 2020/2/21 09:48
* @Description: 流年笑擲 未來可期。以夢為馬,不負韶華!
*/
public class Spark_wordcount_java8 {
public static void main(String[] args){
SparkConf conf = new SparkConf().setAppName("wc").setMaster("local[*]");
JavaSparkContext jsc = new JavaSparkContext(conf);
JavaRDD<String> fileRDD = jsc.textFile("G:\\2020幹貨\\Spark\\wordcount.txt");
JavaRDD<String> wordRDD = fileRDD.flatMap(s -> Arrays.asList(s.split(" ")).iterator());
JavaPairRDD<String, Integer> wordAndOne = wordRDD.mapToPair(w -> new Tuple2<>(w, 1));
JavaPairRDD<String, Integer> wordAndCount = wordAndOne.reduceByKey((a, b) -> a + b);
//wordAndCount.collect().forEach(t->System.out.println(t));
wordAndCount.collect().forEach(System.out::println);
//函數式程式設計的核心思想:行為參數化!
}
}
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運作後的結果是一樣的。
本次的分享就到這裡,受益的小夥伴或對大資料技術感興趣的朋友記得點贊關注Alice喲(^U^)ノ~YO