spark入门: wordcount-java

wordcount-java：

pom.xml文件如下:

<dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.apache.spark</groupId>
      <artifactId>spark-core_2.10</artifactId>
      <version>1.3.0</version>
    </dependency>
    <dependency>
      <groupId>org.apache.spark</groupId>
      <artifactId>spark-sql_2.10</artifactId>
      <version>1.3.0</version>
      </dependency>
    <dependency>
      <groupId>org.apache.spark</groupId>
      <artifactId>spark-hive_2.10</artifactId>
      <version>1.3.0</version>
    </dependency>
    <dependency>
      <groupId>org.apache.spark</groupId>
      <artifactId>spark-streaming_2.10</artifactId>
      <version>1.3.0</version>
    </dependency>
    <dependency>
      <groupId>org.apache.hadoop</groupId>
      <artifactId>hadoop-client</artifactId>
      <version>2.4.1</version>
    </dependency>
    <dependency>
      <groupId>org.apache.spark</groupId>
      <artifactId>spark-streaming-kafka_2.10</artifactId>
      <version>1.3.0</version>
    </dependency>
  </dependencies>

package cn.spark.study.core;

import java.util.Arrays;

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 WordCount3 {
	public static void main(String[] args) {
		SparkConf conf=new SparkConf().setAppName("WorldCountLocal").setMaster("local");
		JavaSparkContext sc=new JavaSparkContext(conf);
		JavaRDD<String> lines=sc.textFile("C:\\Users\\wanglonglong\\Desktop\\word.txt");
		JavaRDD<String> words=lines.flatMap(new FlatMapFunction<String, String>() {

			@Override
			public Iterable<String> call(String t) throws Exception {
				// TODO Auto-generated method stub
				return Arrays.asList(t.split(" "));
			}
		});
		JavaPairRDD<String, Integer> pairs = words.mapToPair(new PairFunction<String, String, Integer>() {

			private static final long serialVersionUID=1;
			@Override
			public Tuple2<String, Integer> call(String word) throws Exception {
				return new Tuple2<String, Integer>(word,1);
			}
		});
		JavaPairRDD<String, Integer> wordCounts = pairs.reduceByKey(
		        new Function2<Integer, Integer, Integer>() {
		            private static final long serialVersionUID = 1L;
		            public Integer call(Integer v1, Integer v2) throws Exception {
		                return v1 + v2;
		            }
		        });
		wordCounts.foreach(new VoidFunction<Tuple2<String,Integer>>() {
		       private static final long serialVersionUID = 1L;
		       public void call(Tuple2<String, Integer> wordCount) throws Exception {
		           System.out.println("("+wordCount._1 + "," + wordCount._2 + " )");
		       }
		   });
		   sc.close();

	}

}