SecondSort_Java

import org.apache.spark.SparkConf;
import org.apache.spark.SparkContext;
import org.apache.spark.api.java.JavaPairRDD;
import org.apache.spark.api.java.JavaSparkContext;
import org.apache.spark.api.java.function.PairFunction;
import scala.Int;
import scala.Tuple2;

import java.util.Arrays;
import java.util.List;

/**
 * Created by MC on 2018/6/6.
 * java编写二次排序，第一个值正序，第二个值倒序
 * 两种写法：
 *          java编写
 *          兰姆达表达式
 *         (把兰姆达表达式进行注释，解开java写法，效果一样)
 *        （个人感觉兰姆达表达式写法比较简单轻便）
 */
public class SecondSort_java {
    public static String mySecondSort(JavaSparkContext jsc){
        List<Tuple2<Integer, Integer>> arr1 = Arrays.asList(
                new Tuple2<Integer, Integer>(11, 5),
                new Tuple2<Integer, Integer>(22, 5),
                new Tuple2<Integer, Integer>(33, 4),
                new Tuple2<Integer, Integer>(33, 5),
                new Tuple2<Integer, Integer>(22, 2),
                new Tuple2<Integer, Integer>(11, 1));
        JavaPairRDD<Integer, Integer> rdd1 = jsc.parallelizePairs(arr1);
        //兰姆达表达式写法
        JavaPairRDD<SecondSortEntity, Tuple2<Integer, Integer>> rdd2 =
                rdd1.mapToPair(x -> new Tuple2<SecondSortEntity, Tuple2<Integer, Integer>>(new SecondSortEntity(x._1, x._2), x));
        JavaPairRDD<SecondSortEntity, Tuple2<Integer, Integer>> rdd3 = rdd2.sortByKey();
        return rdd3.collect().toString();
        //java写法
//        JavaPairRDD<SecondSortEntity, Tuple2<Integer, Integer>> rdd2 = rdd1.mapToPair(new PairFunction<Tuple2<Integer, Integer>, SecondSortEntity, Tuple2<Integer, Integer>>() {
//            @Override
//            public Tuple2<SecondSortEntity, Tuple2<Integer, Integer>> call(Tuple2<Integer, Integer> x) throws Exception {
//                return new Tuple2<SecondSortEntity, Tuple2<Integer, Integer>>(new SecondSortEntity(x._1, x._2), x);
//            }
//        });
//        JavaPairRDD<SecondSortEntity, Tuple2<Integer, Integer>> rdd3 = rdd2.sortByKey();
//        return rdd3.collect().toString();
    }
    public static void main(String[] args){
        SparkConf conf = new SparkConf().setMaster("local").setAppName("SecondSort_java");
        JavaSparkContext jsc = new JavaSparkContext(conf);
        String result = "";
        result = mySecondSort(jsc);
        System.out.println(result);
    }

}

//实体类

import scala.Serializable;
import scala.math.Ordered;

/**
 * Created by MC on 2018/6/6.
 */
public class SecondSortEntity implements Ordered<SecondSortEntity>, Serializable{
    private int num1;
    private int num2;
    public void setNum2(int num2) {
        this.num2 = num2;
    }
    public SecondSortEntity(int num1, int num2) {
        this.num1 = num1;
        this.num2 = num2;
    }
    public SecondSortEntity() {
    }

    @Override
    public boolean $less(SecondSortEntity that) {
        return true;
    }

    @Override
    public boolean $greater(SecondSortEntity that) {
        return false;
    }

    @Override
    public boolean $less$eq(SecondSortEntity that) {
        return $less(that);
    }

    @Override
    public boolean $greater$eq(SecondSortEntity that) {
        return $greater(that);
    }
    @Override
    public int compare(SecondSortEntity that) {
        int result = this.num1-that.num1;
        //设置二次排序方式，当第一个值排序后对第二个值进行二次排序
        if(result == 0)result=that.num2-this.num2;
        return result;
    }
    @Override
    public int compareTo(SecondSortEntity that) {
        return compare(that);
    }
}