import org.apache.spark.SparkConf;
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.VoidFunction;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;

class Map_test implements Function<String,String>{
    @Override
    public String call(String s) throws Exception{
        //方式三
        return s+"方式三";
    }
}

public class java_spark_function {
    public static void main(String[] args) {
        SparkConf conf = new SparkConf().setMaster("local[*]").setAppName("spark_java_function");
        JavaSparkContext sc = new JavaSparkContext(conf);
        List<String> list = Arrays.asList("a","b","c","d");
        JavaRDD<String> parallelize = sc.parallelize(list);
        parallelize.map(
                // 方式一
                x->x+"方式一"
        ).map(
                // 方式二
                new Function<String, String>() {
                    @Override
                    public String call(String s) throws Exception {

                        return s+"方式二";
                    }
                }
        ).map(
                new Map_test()
        ).collect().forEach(x ->System.out.println(x));

        parallelize.flatMap(
                new FlatMapFunction<String, Integer>() {
                    @Override
                    public Iterator<Integer> call(String s) throws Exception {

                        List<Integer> l = new ArrayList();
                        if(s=="a"){
                            l.add(1);
                        }else if(s.toString().equals("b")){
                            l.add(2);
                        }else{
                            l.add(3);
                        }
                        return l.iterator();
                    }
                }
        ).filter(
                new Function<Integer, Boolean>() {
                    @Override
                    public Boolean call(Integer s) throws Exception {
                        if(s<3){

                            return true;
                        }
                        return false;
                    }
                }
        ).foreach(
                new VoidFunction<Integer>() {
                    @Override
                    public void call(Integer integer) throws Exception {
                        System.out.println("输出的结果"+integer);
                    }
                }
        );
    }
}

 

posted on 2020-05-13 14:08  7749ha  阅读(261)  评论(0编辑  收藏  举报