Spark-Eclipse开发环境WordCount
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安装eclipse
解压eclipse-jee-mars-2-win32-x86_64.zip
JavaWordcount
解压spark-2.0.0-bin-hadoop2.6.tgz
创建 Java Project-->Spark
将spark-2.0.0-bin-hadoop2.6下的jars里面的jar全部复制到Spark项目下的lib下
Add Build Path
package com.bean.spark.wordcount; import java.util.Arrays; import java.util.Iterator; 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 org.apache.spark.api.java.function.FlatMapFunction; import org.apache.spark.api.java.function.Function2; import org.apache.spark.api.java.function.PairFunction; import org.apache.spark.api.java.function.VoidFunction; import scala.Tuple2; public class WordCount { public static void main(String[] args) { //创建SparkConf对象,设置Spark应用程序的配置信息 SparkConf conf = new SparkConf(); conf.setMaster("local"); conf.setAppName("wordcount"); //创建SparkContext对象,Java开发使用JavaSparkContext;Scala开发使用SparkContext //SparkContext负责连接Spark集群,创建RDD、累积量和广播量等 JavaSparkContext sc = new JavaSparkContext(conf); //sc中提供了textFile方法是SparkContext中定义的,用来读取HDFS上的 //文本文件、集群中节点的本地文本文件或任何支持Hadoop的文件系统上的文本文件,它的返回值是JavaRDD[String],是文本文件每一行 JavaRDD<String> lines = sc.textFile("D:/tools/data/wordcount/wordcount.txt"); //将每一行文本内容拆分为多个单词 //lines调用flatMap这个transformation算子(参数类型是FlatMapFunction接口实现类)返回每一行的每个单词 JavaRDD<String> words = lines.flatMap(new FlatMapFunction<String, String>() { private static final long serialVersionUID = 1L; @Override public Iterator<String> call(String s) throws Exception { // TODO Auto-generated method stub return Arrays.asList(s.split(" ")).iterator(); } }); //将每个单词的初始数量都标记为1个 //words调用mapToPair这个transformation算子(参数类型是PairFunction接口实现类, //PairFunction<String, String, Integer>的三个参数是<输入单词, Tuple2的key, Tuple2的value>), //返回一个新的RDD,即JavaPairRDD JavaPairRDD<String, Integer> word = words.mapToPair(new PairFunction<String, String, Integer>() { private static final long serialVersionUID = 1L; @Override public Tuple2<String, Integer> call(String s) throws Exception { // TODO Auto-generated method stub return new Tuple2<String, Integer>(s, 1); } }); //计算每个相同单词出现的次数 //pairs调用reduceByKey这个transformation算子(参数是Function2接口实现类)对每个key的value进行reduce操作, //返回一个JavaPairRDD,这个JavaPairRDD中的每一个Tuple的key是单词、value则是相同单词次数的和 JavaPairRDD<String, Integer> counts = word.reduceByKey(new Function2<Integer, Integer, Integer>() { private static final long serialVersionUID = 1L; @Override public Integer call(Integer s1, Integer s2) throws Exception { // TODO Auto-generated method stub return s1 + s2; } }); counts.foreach(new VoidFunction<Tuple2<String,Integer>>() { private static final long serialVersionUID = 1L; @Override public void call(Tuple2<String, Integer> wordcount) throws Exception { // TODO Auto-generated method stub System.out.println(wordcount._1+" : "+wordcount._2); } }); //将计算结果文件输出到文件系统 /* * HDFS * 新版的API * org.apache.hadoop.mapreduce.lib.output.TextOutputFormat * counts.saveAsNewAPIHadoopFile("hdfs://master:9000/data/wordcount/output", Text.class, IntWritable.class, TextOutputFormat.class, new Configuration()); * 使用默认TextOutputFile写入到HDFS(注意写入HDFS权限,如无权限则执行:hdfs dfs -chmod -R 777 /data/wordCount/output) * wordCount.saveAsTextFile("hdfs://soy1:9000/data/wordCount/output"); * * * */ counts.saveAsTextFile("D:/tools/data/wordcount/output"); //关闭SparkContext容器,结束本次作业 sc.close(); } }
运行出错
在代码中加入:只要式加在JavaSparkContext初始化之前就可以
System.setProperty("hadoop.home.dir", "D:/tools/spark-2.0.0-bin-hadoop2.6");
将hadoop2.6(x64)工具.zip解压到D:\tools\spark-2.0.0-bin-hadoop2.6\bin目录下
PythonWordcount
eclipse集成python插件
解压pydev.zip将features和plugins中的包复制到eclipse的对应目录
#-*- coding:utf-8-*- from __future__ import print_function from operator import add import os from pyspark.context import SparkContext ''' wordcount ''' if __name__ == "__main__": os.environ["HADOOP_HOME"] = "D:/tools/spark-2.0.0-bin-hadoop2.6" sc = SparkContext() lines = sc.textFile("file:///D:/tools/data/wordcount/wordcount.txt").map(lambda r: r[0:]) counts = lines.flatMap(lambda x: x.split(' ')) \ .map(lambda x: (x, 1)) \ .reduceByKey(add) output = counts.collect() for (word, count) in output: print("%s: %i" % (word, count))
提交代码到集群上运行
java:
[hadoop@master application]$ spark-submit --master spark://master:7077 --class com.bean.spark.wordcount.WordCount spark.jar
python:
[hadoop@master application]$ spark-submit --master spark://master:7077 wordcount.py