sparkはhdfsファイルを読んでwodcountを実現して、結果をhdfsに保存します。
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package iie.udps.example.operator.spark;
import scala.Tuple2;
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.Function;
import org.apache.spark.api.java.function.Function2;
import org.apache.spark.api.java.function.PairFunction;
import java.util.Arrays;
import java.util.regex.Pattern;
/**
* Spark HDFS , WordCount
*
* :spark-submit --class iie.hadoop.hcatalog.TextFileSparkTest --master
* yarn-cluster /tmp/sparkTest.jar hdfs://192.168.8.101/test/words
* hdfs://192.168.8.101/test/spark/out
*
* @author xiaodongfang
*
*/
public final class TextFileSparkTest {
private static final Pattern SPACE = Pattern.compile(" ");
@SuppressWarnings("serial")
public static void main(String[] args) throws Exception {
if (args.length < 2) {
System.err.println("Usage: JavaWordCount ");
System.exit(1);
}
String inputSparkFile = args[0];
String outputSparkFile = args[1];
SparkConf sparkConf = new SparkConf().setAppName("SparkWordCount");
JavaSparkContext ctx = new JavaSparkContext(sparkConf);
JavaRDD lines = ctx.textFile(inputSparkFile, 1);
JavaRDD words = lines
.flatMap(new FlatMapFunction() {
@Override
public Iterable call(String s) {
return Arrays.asList(SPACE.split(s));
}
});
JavaPairRDD ones = words
.mapToPair(new PairFunction() {
@Override
public Tuple2 call(String s) {
return new Tuple2(s, 1);
}
});
JavaPairRDD counts = ones
.reduceByKey(new Function2() {
@Override
public Integer call(Integer i1, Integer i2) {
return i1 + i2;
}
});
counts.map(new Function, String>() {
@Override
public String call(Tuple2 arg0) throws Exception {
return arg0._1.toUpperCase() + ": " + arg0._2;
}
}).saveAsTextFile(outputSparkFile);
ctx.stop();
}
}