电影评分数据分析案例-[Java]

movie.txt

movie：电影id
rate：用户评分
timeStamp：评分时间
uid：用户id

{"movie":"1193","rate":"5","timeStamp":"978300760","uid":"1"}
{"movie":"661","rate":"3","timeStamp":"978302109","uid":"1"}
{"movie":"3114","rate":"4","timeStamp":"978302174","uid":"1"}
{"movie":"608","rate":"4","timeStamp":"978301398","uid":"1"}
{"movie":"1246","rate":"4","timeStamp":"978302091","uid":"1"}
{"movie":"1245","rate":"2","timeStamp":"978299200","uid":"2"}
{"movie":"1246","rate":"5","timeStamp":"978299418","uid":"2"}
{"movie":"3893","rate":"1","timeStamp":"978299535","uid":"2"}

//用到了JSON jar包

 

 需求

1.每个用户评分最高的3条记录

2.每个用户评分的平均值

3.最大方（评分平均值高）的3个用户

4.最热门的3部电影

5.评价最高的3部电影

..............................

/**
 * @author Taylor
 */
public class MovieBean {
    private String movie;
    private int rate;
    private long timeStamp;
    private int uid;

    public MovieBean() {
    }

    public MovieBean(String movie, int rate, long timeStamp, int uid) {
        this.movie = movie;
        this.rate = rate;
        this.timeStamp = timeStamp;
        this.uid = uid;
    }

    public String getMovie() {
        return movie;
    }

    public void setMovie(String movie) {
        this.movie = movie;
    }

    public int getRate() {
        return rate;
    }

    public void setRate(int rate) {
        this.rate = rate;
    }

    public long getTimeStamp() {
        return timeStamp;
    }

    public void setTimeStamp(long timeStamp) {
        this.timeStamp = timeStamp;
    }

    public int getUid() {
        return uid;
    }

    public void setUid(int uid) {
        this.uid = uid;
    }

    @Override
    public String toString() {
        return "MovieBean{" +
                "movie='" + movie + '\'' +
                ", rate='" + rate + '\'' +
                ", timeStamp='" + timeStamp + '\'' +
                ", uid='" + uid + '\'' +
                '}';
    }

}

 

接着写测试运行类

1.每个用户评分最高的3条记录

import com.alibaba.fastjson.JSON;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.*;

/**
 * @author Taylor
 */

public class Test01_Movies {
    public static void main(String[] args) throws IOException {
        //读文件
        BufferedReader br = new BufferedReader(new FileReader("D:\\movie.txt"));
        //逐行处理
        String line = null;
        HashMap<Integer,ArrayList<Integer>> resMap = new HashMap<>();
        while ((line =br.readLine()) != null){
            //2.1把拿进来的数据转成MovieBean对象
            try{
                MovieBean mb = JSON.parseObject(line,MovieBean.class);
                int uid = mb.getUid();
                int rate = mb.getRate();
                if (resMap.containsKey(uid)){
                    ArrayList<Integer> list = resMap.get(uid);
                   list.add(rate);
                }else{
                    ArrayList<Integer> list = new ArrayList<>();
                    list.add(rate);
                    resMap.put(uid, list);
                }

            }catch(Exception ignore){
            }
        }

        //排序
        for (Map.Entry<Integer, ArrayList<Integer>> entry : resMap.entrySet()) {
            Integer uid = entry.getKey();
            ArrayList<Integer> list = entry.getValue();
            Collections.sort(list,new Comparator<Integer>() {

                @Override
                public int compare(Integer o1, Integer o2) {
                    return o2-o1;
                }
            });
            System.out.print(uid +"\t");
            for (int i = 0; i <Math.min(3,list.size()); i++) {
                Integer rate = list.get(i);
                System.out.print(rate +"\t");
            }
            System.out.println();
        }
    }
}

----------------------------------------------------------------------------------------------------------------------

2.每个用户评分的平均值

import com.alibaba.fastjson.JSON;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

/**
 * @author Taylor
 */

//每个用户评分的平均值
@SuppressWarnings("all")
public class Test2_Movies {
    public static void main(String[] args) throws IOException {
        //读文件
        BufferedReader br = new BufferedReader(new FileReader("D:\\movie.txt"));
        //逐行处理
        String line = null;
        HashMap<Integer,ArrayList<Integer>> resMap = new HashMap<>();
        while ((line =br.readLine()) != null){
            //2.1把拿进来的数据转成MovieBean对象
            try{
                MovieBean mb = JSON.parseObject(line,MovieBean.class);
                int uid = mb.getUid();
                int rate = mb.getRate();
                if (resMap.containsKey(uid)){
                    ArrayList<Integer> list = resMap.get(uid);
                    list.add(rate);
                }else{
                    ArrayList<Integer> list = new ArrayList<>();
                    list.add(rate);
                    resMap.put(uid, list);
                }

            }catch(Exception ignore){
            }
        }

            //遍历map 拿出每一个人的uid 和对应的评分集合
        for (Map.Entry<Integer,ArrayList<Integer>> entry : resMap.entrySet()){
            Integer uid = entry.getKey();
            ArrayList<Integer> rates = entry.getValue();
            //遍历集合求平均值
            int sum=0;
            for (Integer rate : rates) {
                sum += rate;
            }

            //求平均值(不保留两位小数)
            double avgRate = sum / (rates.size() * 1.0);
            //System.out.println(uid+"评论的平均分为 "+avgRate);

            //保留两位小数
            DecimalFormat df = new DecimalFormat("#.00");
            System.out.println(uid+"评论的平均分为 "+df.format(avgRate));
        }

    }
}

----------------------------------------------------------------------------------------------------------------------------

3.评分平均值最高的3个用户

import com.alibaba.fastjson.JSON;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.*;

/**
 * @author Taylor
 */
@SuppressWarnings("all")
public class Test03_Movies {
    public static void main(String[] args) throws IOException {
        //读文件
        BufferedReader br = new BufferedReader(new FileReader("D:\\movie.txt"));
        //逐行处理
        String line = null;
        HashMap<Integer,ArrayList<Integer>> resMap = new HashMap<>();
        while ((line =br.readLine()) != null){
            //2.1把拿进来的数据转成MovieBean对象
            try{
                MovieBean mb = JSON.parseObject(line,MovieBean.class);
                int uid = mb.getUid();
                int rate = mb.getRate();
                if (resMap.containsKey(uid)){
                    ArrayList<Integer> list = resMap.get(uid);
                    list.add(rate);
                }else{
                    ArrayList<Integer> list = new ArrayList<>();
                    list.add(rate);
                    resMap.put(uid, list);
                }

            }catch(Exception ignore){
            }
        }

        //用一个Map收集用户id和平均分
        HashMap<Integer, Double> result = new HashMap<>();

        //遍历map 拿出每一个人的uid和对应的评分集合
        for (Map.Entry<Integer, ArrayList<Integer>> entry : resMap.entrySet()) {
            Integer uid = entry.getKey();
            ArrayList<Integer> rates = entry.getValue();
            //遍历集合求平均值
            int sum = 0;
            for (Integer rate : rates) {
                sum += rate;
            }
            //求平均值
            double avgRate = sum / (rates.size() * 1.0);
            result.put(uid, avgRate);
        }
        //对平均分排序
        ArrayList<Map.Entry<Integer, Double>> list = new ArrayList<>(result.entrySet());
        Collections.sort(list, new Comparator<Map.Entry<Integer, Double>>() {
            @Override
            public int compare(Map.Entry<Integer, Double> o1, Map.Entry<Integer, Double> o2) {
                return Double.compare(o2.getValue(), o1.getValue());
            }
        });
        for (int i = 0; i < Math.min(3, list.size()); i++) {
            System.out.println(list.get(i));
        }
    }
}

------------------------------------------------------------------------------------

4.最热门的3部电影

import com.alibaba.fastjson.JSON;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.util.*;

/**
 * @author Taylor
 */

public class Test04_Movies {
    public static void main(String[] args) throws Exception {
        //读文件
        BufferedReader br = new BufferedReader(new FileReader("D:\\movie.txt"));
        //逐行处理
        HashMap<String,Integer> resMap=new HashMap<>();
        String line = null;
        while ((line = br.readLine()) != null){
            try {
                MovieBean mb = JSON.parseObject(line, MovieBean.class);
                String movieId = mb.getMovie();
                if (resMap.containsKey(movieId)){
                    Integer cnts = resMap.get(movieId);
                    cnts++;
                    resMap.put(movieId, cnts);
                }else{
                    resMap.put(movieId,1);
                }
            } catch (Exception e) {
            }
        }
        //排序
        ArrayList<Map.Entry<String, Integer>> list = new ArrayList<>(resMap.entrySet());
        Collections.sort(list,new Comparator<Map.Entry<String, Integer>>(){

            @Override
            public int compare(Map.Entry<String, Integer> o1, Map.Entry<String, Integer> o2) {
                return o2.getValue()-o1.getValue();
            }
        });
        for (int i = 0; i < Math.min(3, list.size()); i++) {
            System.out.println(list.get(i));
        }
    }
}

-------------------------------------------------------------------------------------

5.评价最高的3部电影

import com.alibaba.fastjson.JSON;

import java.io.BufferedReader;
import java.io.FileReader;
import java.util.*;

/**
 * @author Taylor
 */

public class Test05_Movies {
    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new FileReader("D:\\movie.txt"));
        String line = null;
        HashMap<String,ArrayList<Integer>> resMap = new HashMap<String,ArrayList<Integer>>();
        while ((line = br.readLine()) != null){
            try {
                MovieBean mb = JSON.parseObject(line,MovieBean.class);
                String movieId = mb.getMovie();
                int rate = mb.getRate();

                if (resMap.containsKey(movieId)){
                    ArrayList<Integer> list = resMap.get(movieId);
                    list.add(rate);
                    resMap.remove(movieId,list);
                }else{
                    ArrayList<Integer> list = new ArrayList<>();
                    list.add(rate);
                    resMap.put(movieId,list);
                }
            } catch (Exception ignore) {
            }
        }

        HashMap<String,Double> result = new HashMap();
        //遍历map 求出每一部电影的平均值
        for (Map.Entry<String, ArrayList<Integer>> entry : resMap.entrySet()) {
            String movieId = entry.getKey();
            ArrayList<Integer> list = entry.getValue();
            int sum = 0;
            for (Integer integer : list) {
                sum+=integer;
            }
            double avgRate = sum / (list.size() * 1.0);
            result.put(movieId, avgRate);
        }

        //排序
        ArrayList<Map.Entry<String, Double>> resultList = new ArrayList<>(result.entrySet());
        Collections.sort(resultList, new Comparator<Map.Entry<String, Double>>() {
            @Override
            public int compare(Map.Entry<String, Double> o1, Map.Entry<String, Double> o2) {
                return Double.compare(o2.getValue(),o1.getValue());
            }
        });

        for (int i = 0; i < Math.min(3, result.size()); i++) {
            System.out.println(resultList.get(i));
        }

    }
}