Data analysis case 1 QQ friend relationship analysis

1. Social user relationship analysis
Data example:
the left side of the colon is the user id, and the right side of the colon is the user's friend list
Requirement 1: The number of friends of each user (user) Tao Ge: 7 Yang Ge: 5
Steps: 1): Use io stream Read data
2): Divide each line of data
       1; Use: Divide ---> User Friend List (String)
       2; Divide the buddy list again (,)
3) Ask for the number
of friends 4) According to the number of friends Sort by quantity
//Completed
Requirement 2: Common friends between two pairs The common friends
of Brother Tao and Brother Yang are: Brother Yuan, Brother Xing The common friends of Brother
Tao and Brother Yuan are: . . . . . .
1: Read data
2: Data segmentation
1): Divide by colon User friend list
2): Divide the friend list ---> each friend
3: Load the data into the map set
4: Get the friend list (Two pairs of users seeking common friends)
5: Find common friends of two users
6: Output the result (save the result to a file) userId: friend 1, friend 2.. . . Brother Tao: Brother Yang, Brother Yuan, Handsome, Ding Ding, Brother Xing, Xiaopengpeng, Sister Na Brother Yang : Brother Tao, Brother Yuan, Brother Xing, Brother Hui, Brother Yang Yuan Brother: Brother Ding, Brother Tao, Handsome, Brother Handsome : Brother Tao, Brother Xing, Ding Ding, Brother Kan






Brother Xing: Brother Yang, Brother Yuan, Handsome, Brother Kai, Brother Kan
Ding Ding : Brother Tao, Brother Yang, Brother Yuan, Handsome, Brother Xing, Brother Xiaopeng
, Brother Kai Shuaishuai, Xingge,
Dingding Sister Na: Brother Tao, Brother Yuan, Shuaishuai, Brother Xing, Xiaopengpeng Xingge:
Brother Tao, Xiaopengpeng
Sister Ma : Brother Yang, Xiaopengpeng Brother
Hui: Brother Tao, Brother Yuan, Handsome Brother
Kan : Handsome, Brother Xing, Ding Ding Brother
Kai: Brother Xing, Ding Ding
, Brother Ma Xiaopeng Peng: Brother Tao, Sister Na, Brother Xing, Brother Ma

Country: Tao Ge

implementation code

1 friend.txt

Brother Tao: Brother Yang, Brother Yuan, Shuaishuai, Dingding, Brother Xing, Xiaopengpeng, Sister Na
Brother Yang: Brother Tao, Brother Yuan, Brother Xing, Brother Hui, Brother Yang
Brother Yuan: Ding Ding, Brother Tao, Handsome, Brother Xing
Handsome: Brother Tao, Brother Xing, Ding Ding, Brother Kan
Brother Xing: Brother Yang, Brother Yuan, Shuaishuai, Brother Kai, Brother Kan
Ding Ding: Brother Tao, Brother Yang, Brother Yuan, Shuaishuai, Brother Xing, Xiaopengpeng, Brother Kai
Brother Ma: Brother Tao, Brother Yuan, Handsome, Brother Xing, Ding Ding
Sister Na: Brother Tao, Brother Yuan, Shuaishuai, Brother Xing, Xiaopengpeng
Brother Xing: Brother Tao, Xiao Pengpeng
Sister Ma: Brother Yang, Xiao Pengpeng
Brother Hui: Brother Tao, Brother Yuan, Handsome
Kan brother: handsome, star brother, ding ding
Brother Kai: Brother Xing, Ding Ding, Brother Ma
Xiaopengpeng: Brother Tao, Sister Na, Brother Xing, Sister Ma
Country: Tao Ge

    FileToArrayList.java

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
public class FileToArrayList {
	public static void main(String[] args) throws IOException {
		// Read data from a text file (one string per row) into the collection, and traverse the collection
		String srcPath = "D:\\New Folder(18)\\Case 1\\src\\ch01\\Friends.txt";
		List<String> list = fileToArrayList(srcPath);
		for (String s : list) {
			System.out.println(s);
		}
		InputStream is =null;
		is = new FileInputStream("D:\\New Folder(18)\\Case 1\\src\\ch01\\Friends.txt");
		InputStreamReader isr = new InputStreamReader(is,"utf-8");
		BufferedReader bfReader = new BufferedReader(isr);
		String line = null;
		line = bfReader.readLine();
		while(line!=null){
			String[] user = line.split(":");
			}
		}
	/**
	 * Read the content from the specified file into the collection
	 * @param srcPath
	 * @return
	 */
	private static List<String> fileToArrayList(String srcPath) {
		List<String> list = new ArrayList<String>();
		try (BufferedReader br = new BufferedReader(new FileReader(srcPath));) {
			String line;// is used to save the content of the line read each time
			while ((line = br.readLine()) != null) {
				list.add(line);
			}
			return list;
		} catch (Exception e) {
			e.printStackTrace ();
			return null;
		}
	}
}

    3 MainTest

import java.io.BufferedReader;
import java.io.FileReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
/**
 * 1. Use IO stream to read data (bufferedReader), each line of data is read
 * 2. Use string segmentation (1) Use colon to split, username, friend list
 * (2) The friend list is divided, and each friend Map<user and friend list> Map<user name and length> is converted into list sorting
 * 3. Obtain the number of friends corresponding to the user (the length behind)
 * 4. Sort by quantity
 */
public class MainTest {
	public static void main(String[] args) {
		Map<String, List<String>> map = getUserInfo();
		HashMap<String, Integer> map2 = new HashMap<>();
		Set<Entry<String,List<String>>> entrySet = map.entrySet();
		for(Entry<String, List<String>> entry : entrySet){
		map2.put(entry.getKey(),entry.getValue().size());
		}
		//System.out.println(map2);
		List<UserNameCount> list=new ArrayList<>();
		for(Entry<String,Integer> entry : map2.entrySet()){
			UserNameCount user = new UserNameCount();
			user.setUserName(entry.getKey());
			user.setCount(entry.getValue());
			list.add(user);
		}
		//sort
		Collections.sort(
			list, new Comparator<UserNameCount>(){
			@Override
			public int compare(UserNameCount o2, UserNameCount o1) {
				return o1.getCount()-o2.getCount();
				}
				});
		for(UserNameCount s : list){
			System.out.println("User name:"+s.getUserName()+" "+"Number of friends:"+s.getCount());
		}
		}
	public static Map<String,List<String>> getUserInfo() {
		Map<String,List<String>> map = new HashMap<>();
		try (BufferedReader br = new BufferedReader(new FileReader("D:\\好友.txt"));) {
			String line = null;
			while ((line = br.readLine()) != null) {
				//System.out.println(line);
				//Use string split and save to array
				String[] split = line.split(":");
				String username = split[0];
				String[] fs = line.split(",");
				//System.out.println(Arrays.toString(fs));  
				//Array.asList cannot add or delete operations
				map.put(username, Arrays.asList(fs));	
			}
		} catch (Exception e) {
			e.printStackTrace ();
		}
		return map;
	}
}

4 MainTest2

import java.io.BufferedReader;
import java.io.FileReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

/**
 * 1. Use IO stream to read data (bufferedReader), each line of data is read over 2. Use string division (1) Use colon to divide, user name, friend list
 * (2) The friend list is divided, and each friend Map<user and friend list> Map<user name and length> is converted into list sorting 3. Find the number of friends corresponding to the user (the length behind)
 * 4. Sort code optimization according to quantity
 */
public class MainTest2 {
	public static void main(String[] args) {
		Map<String, List<String>> map = getUserInfo();
		HashMap<String, Integer> map2 = new HashMap<>();
		Set<Entry<String, List<String>>> entrySet = map.entrySet();
		for (Entry<String, List<String>> entry : entrySet) {
			map2.put(entry.getKey(), entry.getValue().size());
		}
		// System.out.println(map2);
		// Directly use generics to unify a format, put them in the set collection, and output the key and value directly,
		Set<Entry<String, Integer>> entrySet2 = map2.entrySet();
		ArrayList<Entry<String, Integer>> list = new ArrayList<>(entrySet2);
		Collections.sort(list, new Comparator<Entry<String, Integer>>() {
			@Override
			public int compare(Entry<String, Integer> o1, Entry<String, Integer> o2) {
				return o1.getValue() - o2.getValue();
			}
		});
		for (Entry<String, Integer> s : list) {
			System.out.println(s);
		}
	}
	public static Map<String, List<String>> getUserInfo() {
		Map<String, List<String>> map = new HashMap<>();
		try (BufferedReader br = new BufferedReader(new FileReader("D:\\好友.txt"));) {
			String line = null;
			while ((line = br.readLine()) != null) {
				// System.out.println(line);
				// Use string split and save to array
				String[] split = line.split(":");
				String username = split[0];
				String[] fs = line.split(",");
				// System.out.println(Arrays.toString(fs));
				// Array.asList cannot add or delete
				map.put(username, new ArrayList<>(Arrays.asList(fs)));
				//map.put(username, Arrays.asList(fs));	
			}
		} catch (Exception e) {
			e.printStackTrace ();
		}
		return map;
	}
}

5.MainTest3

import java.util.List;
import java.io.BufferedWriter;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.util.ArrayList;
import java.util.Map;
import java.util.Set;

public class MainTest3 {
	public static void main(String[] args) throws Exception  {
		BufferedWriter bf = new BufferedWriter(new FileWriter("D:\\lijian.txt"));
		// get friend list
		Map<String, List<String>> userInfo = MainTest2.getUserInfo();
		// get user list
		Set<String> userSet = userInfo.keySet();
		// save to list
		ArrayList<String> userList = new ArrayList<>(userSet);
		// print list length
		// System.out.println(userList.size());
		// Loop comparison, similar to bubbling
		String user1 = null;
		String user2 = null;
		List<String> list3 = null;
		for (int i = 0; i < userList.size() - 1; i++) {// Control the number of times
			// get the first user
			 user1 = userList.get(i);
			List<String> list1 = userInfo.get(user1);
			for (int j = i + 1; j < userList.size(); j++) {
				// get the second user
				 user2 = userList.get(j);
				// as a reference, cannot operate on raw data
				List<String> list2 = userInfo.get(user2);
				// must operate on raw data
				 list3 = new ArrayList(list2);
				// take the intersection
				list3.retainAll(list1);
				if (list3 != null && list3.size() > 0) {
					// can be spliced ​​according to the required data
					System.out.println(user1 + " and " + user2 + " mutual friends " + list3);
					String str = user1 + " mutual friend with " + user2 + " " + list3;
					// save to file
					try {
						bf.write(str);
						bf.newLine();
						bf.flush();
					} catch (Exception e) {
						e.printStackTrace ();
					}
					}
					}
					}	
		bf.close();
		}

	}

6.

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

public class TestComFs {
public static void main(String[] args) {
	ComFs();
}
private static void ComFs() {
	Map<String,List<String>> userInfo = MainTest2.getUserInfo();
	String name1 = "涛哥";
	String name2 = "远哥";
	//Get user 1's friend list
	List<String> list1 = userInfo.get(name1);
	List<String> list2 = userInfo.get(name2);
	ArrayList<String> arraylist = new ArrayList<String>(list1);
	arraylist.retainAll(list2);
	System.out.println(arraylist);
}
}

7.

public class UserBean {
	MainTest3 user1 = new MainTest3();
	MainTest3 user2 = new MainTest3();
	MainTest3 list3 = new MainTest3();
}

8.

public class UserNameCount {
	private String userName;
	private Integer count;
	public String getUserName() {
		return userName;
	}
	public void setUserName(String userName) {
		this.userName = userName;
	}
	public Integer getCount() {
		return count;
	}
	public void setCount(Integer count) {
		this.count = count;
	}
	@Override
	public String toString() {
		return "UserNameCount [userName=" + userName + ", count=" + count + "]";
	}
	
}