Spark Streaming---PersistMySQL Work Count(java)

package com.spark.streaming;import java.sql.Connection;import java.sql.Statement;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.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 org.apache.spark.streaming.Durations;import org.apache.spark.streaming.api.java.JavaDStream;import org.apache.spark.streaming.api.java.JavaPairDStream;import org.apache.spark.streaming.api.java.JavaStreamingContext;import scala.Tuple2;public class PersistMySQLWordcount {    public static void main(String[] args) {        SparkConf conf = new SparkConf().setMaster("local[1]").setAppName("PersistMySQLWordcount");        JavaStreamingContext jssc = new JavaStreamingContext(conf, Durations.seconds(5));        JavaDStream<String> lines = jssc.textFileStream("hdfs://node12:8020/Spark/Streaming/WordCount");        JavaDStream<String> words = lines.flatMap(new FlatMapFunction<String, String>() {            private static final long serialVersionUID = 1L;            @Override            public Iterable<String> call(String line) throws Exception {                return Arrays.asList(line.split(" "));            }        });        JavaPairDStream<String, Integer> pairs = words.mapToPair(new PairFunction<String, String, Integer>() {            private static final long serialVersionUID = 1L;            @Override            public Tuple2<String, Integer> call(String word) throws Exception {                return new Tuple2<String,Integer>(word, 1);            }        });        JavaPairDStream<String, Integer> wordcounts = pairs.reduceByKey(new Function2<Integer, Integer, Integer>() {            private static final long serialVersionUID = 1L;            @Override            public Integer call(Integer v1, Integer v2) throws Exception {                return v1 + v2;            }        });        wordcounts.print();        wordcounts.foreachRDD(new VoidFunction<JavaPairRDD<String, Integer>>() {            private static final long serialVersionUID = 1L;            @Override            public void call(JavaPairRDD<String, Integer> wordcountsRDD) throws Exception {                wordcountsRDD.foreachPartition(new VoidFunction<Iterator<Tuple2<String,Integer>>>() {                    private static final long serialVersionUID = 1L;                    @Override                    public void call(Iterator<Tuple2<String, Integer>> wordcounts) throws Exception {                        Connection conn = ConnectionPool.getConnection();                        Tuple2<String, Integer> wordcount = null;                        while(wordcounts.hasNext()){                            wordcount = wordcounts.next();                            String sql = "insert into wordcount(word,count) "                                    + "values('" + wordcount._1 + "'," + wordcount._2 + ")";                            Statement stmt = conn.createStatement();                            stmt.executeUpdate(sql);                        }                        ConnectionPool.returnConnection(conn);                    }                });            }        });        jssc.start();        jssc.awaitTermination();        jssc.close();    }}