Bael 1166 intro apache spark (#2812)

* Changes for BAEL-1166 * Changes for BAEL_1166 * Changes for BAEL 1166 * Changes for BAEL 1166
2017-10-23 11:46:20 +05:30
parent 4ebeb99911
commit 3085db7b30
3 changed files with 100 additions and 0 deletions
@@ -0,0 +1,53 @@
+package com.baeldung;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.regex.Pattern;
+
+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.*;
+import org.apache.spark.api.java.function.Function2;
+import org.apache.spark.api.java.function.PairFunction;
+
+import scala.Tuple2;
+
+public class WordCount {
+
+    private static final Pattern SPACE = Pattern.compile(" ");
+    
+    public static void main(String[] args) throws Exception {
+    if (args.length < 1) {
+        System.err.println("Usage: JavaWordCount <file>");
+        System.exit(1);
+    }
+    SparkConf sparkConf = new SparkConf().setAppName("JavaWordCount").setMaster("local");
+    JavaSparkContext ctx = new JavaSparkContext(sparkConf);
+    JavaRDD<String> lines = ctx.textFile(args[0], 1);
+
+    JavaRDD<String> words = lines.flatMap(s -> Arrays.asList(SPACE.split(s)).iterator());
+    JavaPairRDD<String, Integer> ones = words.mapToPair(
+      new PairFunction<String, String, Integer>() {
+          @Override
+          public Tuple2<String, Integer> call(String s) {
+              return new Tuple2<>(s, 1);
+          }
+      });
+
+    JavaPairRDD<String, Integer> counts = ones.reduceByKey(
+      new Function2<Integer, Integer, Integer>() {
+          @Override
+          public Integer call(Integer i1, Integer i2) {
+              return i1 + i2;
+          }
+      });
+
+    List<Tuple2<String, Integer>> output = counts.collect();
+    for (Tuple2<?, ?> tuple : output) {
+        System.out.println(tuple._1() + ": " + tuple._2());
+    }
+    ctx.stop();
+}
+}