实现的方法很多，这边给出其中一种，也比较基础的一种，可以尝试加入并发？

package com.wd.bigdata.javaexample.proxy;

import java.util.*;

/**
 * Created by taylorchen on 1/7/2017.
 */
public class SortExample {


    public static void main(String[] args) {

        final int SEED = 50;

        final Random random = new Random();

        List<List<Integer>> datas = new ArrayList<List<Integer>>();
        for(int i=0;i<3;i++){

            List<Integer> row = new ArrayList<Integer>();
            int elementCount = random.nextInt(SEED);

            for(int r = 0 ;r<elementCount;r++){
                int t = random.nextInt(SEED);
                    row.add(t);
            }
            for(int k=0;k<row.size();k++){
                for(int j = k + 1;j<row.size();j++){

                    if(row.get(k) >row.get(j)){
                        int t =  row.get(k);
                        row.set(k,row.get(j));
                        row.set(j,t);
                    }

                }

            }

            datas.add(row);
        }

        List<Integer> mergedSortedResult = mergeSort(datas);

        System.out.println(mergedSortedResult);




    }


    public static List<Integer> mergeSort(List<List<Integer>> datas) {
        //返回结果
        List<Integer> sortedList = new ArrayList<Integer>();

        int restRows = datas.size();
        //记录二维数据集内当前的下标
        Integer[][] map = new Integer[datas.size()][2];
        //记录便利完成的子集合
        int[] deadRow = new int[datas.size()];

        //初始化
        for(int e=0;e<datas.size();e++){
            map[e][0] = e;
            map[e][1] = 0;
        }

        Integer[] minEntry = null;
        while (restRows >= 0) {

             minEntry = map[(0 & (datas.size() - 1))];
            for (int i = 0; i < datas.size(); i++) {
                Integer[] location = map[i];
                if(deadRow[minEntry[0]] < 0){
                    continue;
                }
                try{
                    if (datas.get(minEntry[0]).get(minEntry[1]) >
                            datas.get(location[0]).get(location[1])) {
                        minEntry = location;
                    }

                }catch (NullPointerException var1){
                    System.out.println(minEntry);
                    System.out.println(location);
                }

            }
            sortedList.add(datas.get(minEntry[0]).get(minEntry[1]));

            if (minEntry[1] == datas.get(minEntry[0]).size() - 1) {
                restRows--;
                deadRow[minEntry[0]] = -1;
            } else {
                map[minEntry[0]][1] = map[minEntry[0]][1] + 1;
            }
        }

        return sortedList;
    }
}