Java实现Spark groupByKey等算子

谁借莪１个温暖的怀抱￠ 2022-04-13 14:53 202阅读 0赞

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.Function;
    import org.apache.spark.api.java.function.PairFunction;
    import org.apache.spark.sql.Dataset;
    import org.apache.spark.sql.Row;
    import org.apache.spark.sql.SparkSession;
    import org.apache.spark.storage.StorageLevel;
    import scala.Tuple2;
    
    import java.util.*;
    
    public class baobiao {
        public static void main(String[] args) {
            SparkSession spark = SparkSession.builder().appName("dup").master("local[4]").getOrCreate();
            JavaRDD<String> input = spark.sparkContext().textFile("/Users/yangyang/Desktop/textbook_exercise_use_report.csv",1)
                    .toJavaRDD().map(new Function<String, String>() {
                        public String call(String s) throws Exception {
                            String[] tmp = s.split(",");
                            String[] timestamp= tmp[9].split(" ")[0].split("-");
                            String time = "";
                            for(int i =0 ;i < timestamp.length-1;i++){
                                time += timestamp[i];
                            }
                            tmp[9] = time;
                            String res = "";
                            for(int i = 0;i<tmp.length;i++)
                                res += tmp[i]+",";
                            return res;
                        }
                    }).persist(StorageLevel.MEMORY_ONLY());
            JavaPairRDD<String,Integer> all_people= input.mapToPair(new PairFunction<String, String, Integer>() {
                public Tuple2<String,Integer> call(String str) throws Exception{
                    String[] tmp = str.split(",");
                    String key = "";
                    for(int i=1;i<=4;i++)
                        key += tmp[i]+"\t";
                    key += tmp[6];
                    return new Tuple2(key,1);
                }
            }).groupByKey().mapToPair(new PairFunction<Tuple2<String,Iterable<Integer>>, String, Integer>() {
                public Tuple2<String,Integer> call(Tuple2<String,Iterable<Integer>> pairs) throws Exception{
                    String key = pairs._1();
                    Iterable<Integer> iter = pairs._2();
                    int sum = 0;
                    for(Integer i:iter)
                        sum +=i;
                    return new Tuple2(key,sum);
                }
            });
            JavaPairRDD<String,Integer> all_times = input.mapToPair(new PairFunction<String, String, Integer>() {
                public Tuple2<String,Integer> call(String str) throws Exception{
                    String[] tmp = str.split(",");
                    String key = "";
                    for(int i=1;i<=4;i++)
                        key += tmp[i]+"\t";
                    key += tmp[6];
                    return new Tuple2(key,Integer.valueOf(tmp[11]));
                }
            }).groupByKey().mapToPair(new PairFunction<Tuple2<String,Iterable<Integer>>, String, Integer>() {
                        public Tuple2<String,Integer> call(Tuple2<String,Iterable<Integer>> pairs) throws Exception{
                            String key = pairs._1();
                            Iterable<Integer> iter = pairs._2();
                            int sum = 0;
                            for(Integer i:iter)
                                sum +=i;
                            return new Tuple2(key,sum);
                        }
                    });
            JavaPairRDD<String,Integer> all_learn_times = input.mapToPair(new PairFunction<String, String, Integer>() {
                public Tuple2<String,Integer> call(String str) throws Exception{
                    String[] tmp = str.split(",");
                    String key = "";
                    for(int i=1;i<=4;i++)
                        key += tmp[i]+"\t";
                    key += tmp[6];
                    return new Tuple2(key,Integer.valueOf(tmp[10]));
                }
            }).groupByKey().mapToPair(new PairFunction<Tuple2<String,Iterable<Integer>>, String, Integer>() {
                public Tuple2<String,Integer> call(Tuple2<String,Iterable<Integer>> pairs) throws Exception{
                    String key = pairs._1();
                    Iterable<Integer> iter = pairs._2();
                    int sum = 0;
                    for(Integer i:iter)
                        sum +=i;
                    return new Tuple2(key,sum);
                }
            });
            List<Tuple2<String,Integer>> all_people_list= all_people.collect();
            List<Tuple2<String,Integer>> all_times_list= all_times.collect();
            List<Tuple2<String,Integer>> all_learn_times_list= all_learn_times.collect();
            
            for(Tuple2<String,Integer> people:all_learn_times_list)
                System.out.println(people._1()+"\t"+people._2());
            input.foreach(x -> System.out.println(x));
            spark.close();
        }
    }

> 注：Mac下使用idea开发，可用Alt+/看方法返回类型(本人个人习惯设置，写在此怕忘记)