MapReduce实战（六）

package com.darrenchan.test;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

public class Test {
    public static void main(String[] args) throws Exception {
        FileInputStream fis = new FileInputStream(new File("data.txt"));
        InputStreamReader isr = new InputStreamReader(fis);
        BufferedReader br = new BufferedReader(isr);
        String line = null;

        // 将文件中的内容存到list中
        List<String> list = new ArrayList<String>();
        while ((line = br.readLine()) != null) {
            list.add(line);
        }

        Map<String, List<String>> map = new LinkedHashMap<>();
        // 对list进行处理
        for (int i = 0; i < list.size(); i++) {
            for (int j = i + 1; j < list.size(); j++) {
                //临时的list，用于拼接最后结果中的共同好友
                List<String> tempList = new ArrayList<>();
                //按照":"进行分割
                String keyi = list.get(i).split(":")[0];
                String keyj = list.get(j).split(":")[0];
                String contenti = list.get(i).split(":")[1];
                String contentj = list.get(j).split(":")[1];

                //让i层的每一个好友分别和j层的好友找共同好友
                String[] fields = contenti.split(",");
                for (int k = 0; k < fields.length; k++) {
                    if (contentj.contains(fields[k])) {
                        tempList.add(fields[k]);
                    }
                }
                
                // 如果tempList里面有内容说明就是有相同元素
                if (tempList.size() > 0) {
                    map.put(keyi + "," + keyj, tempList);
                }
            }
        }

        // 打印map
        for (String key : map.keySet()) {
            System.out.println(key + ":" + map.get(key));
        }
    }
}