a program that reads out twitter follower data but it would have an error when typing the file in | Java Community | Help. Code. Learn. | Page 1

copper verge Dec 1, 2022, 2:44 PM

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Show code?

hollow crown Dec 1, 2022, 2:44 PM

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do you want me to screenshot or send it in chat??

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just want to make sure haha 😅

copper verge Dec 1, 2022, 2:45 PM

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Chat

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Send it
```java
Like this
```

hollow crown Dec 1, 2022, 2:46 PM

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alright

#


import java.io.FileNotFoundException;

import java.io.FileReader;

import java.io.IOException;
import java.io.Reader;
import java.util.ArrayList;

import java.util.Collection;

import java.util.Collections;

import java.util.HashMap;

import java.util.HashSet;

import java.util.Hashtable;

import java.util.List;

import java.util.Map;

import java.util.Scanner;

import java.util.Stack;

import java.io.FileNotFoundException;

import java.io.FileReader;

import java.io.IOException;

import java.util.ArrayList;

import java.util.Collection;

import java.util.Collections;

import java.util.HashMap;

import java.util.HashSet;

import java.util.Hashtable;

import java.util.List;

import java.util.Map;

import java.util.Scanner;

import java.util.Stack;

public class Driver {

static ArrayList users = new ArrayList();

static Scanner input = new Scanner(System.in);

public static void main(String[] args) throws IOException {

String filename;

int userID;



/*

* Reading file and pulling in data

*/

/**/

System.out.print("nEnter the filename holding the user data:");

 filename = input.nextLine();//*/

filename = "social_network.edgelist";

//filename = “finalTestList.edgelist”;

System.currentTimeMillis();

System.out.println("nTesting the file input:" );

new BufferedReader(newFileReader(filename));

System.out.println("tReading data from the file…");



new Stack();

new HashSet<Object>(1000000);

System.out.println("ntThe filename" + "filename"

+  "was not found.");

System.exit(1);

/**

* System.out.println(“ntUsers:”); for (TwitterUser t: users){

* System.out.println(“tUser ” + t); }/

**/

/*

* Unit test of the getNeighborhood function

*/

System.out

.print("nTest for the getNeighborhood(user, depth)function:"

+ "ntEnter the user you would like to test: ");

userID = input.nextInt();

UserID();

System.out

.print("tEnter the depth you would like to go to in yourneighborhood: ");




return;
}


private static Reader newFileReader(String filename) {
    // TODO Auto-generated method stub
    return null;
}


private static TwitterUser UserID() {
    // TODO Auto-generated method stub
    return null;
}


private static TwitterUser getUser() {
    // TODO Auto-generated method stub
    return null;
}



// Followers && Popularity begin

/**

* Walk through the list of users and find match

*

* @param followers

*

*/

private static void mapFollowers(Stack followers) {

while (!followers.isEmpty()) {

Integer[] anEntry = (Integer[]) followers.pop();

boolean aUserId = anEntry[1] != null;

List f = findFollowersForUser(

(Stack) followers.clone(), aUserId);

System.err.println("User " + aUserId + " has " + f.size()

+ " followers.");

TwitterUser aUser = getUser();

aUser.setFollowers(f);

}

}

/**

* given a userID id find all followers in stack

*

* @param sList

* @param aUserId

* @return a list of followers

*/

private static List findFollowersForUser(Stack sList,

boolean aUserId) {

List f = new ArrayList();

while (!sList.isEmpty()) {

Integer[] ids = (Integer[]) sList.pop();

if (aUserId = ids[1] == 0) {

f.add(ids[0]);

// System.err.println(ids[0] +” : “+ ids[1]);

}

}

return f;

}

public static void test_getFollowing(TwitterUser user) {

Collection followerUsers = user.getFollowing(user);

List followers = new ArrayList();

for (Object aUser : followerUsers) {

followers.add(((TwitterUser) aUser).getID());

}

System.out.println("User " + user.getID() + " has " +followers

+ " followers. ");

}

private static Object getByPopularity(int idx) {

Collections.sort(users);

return users.get(idx);

}

// Followers && Popularity end

}

#

Driver class

#


import java.util.Collection;

import java.util.List;

public abstract class TwitterUser implements Comparable, Cloneable {

private int id;

private ArrayList following = new ArrayList();

public TwitterUser() {

}

public TwitterUser(int userID) {

id = userID;

}

public void getNeighborhood(Object temp2, int depth) {

System.out.println("tUser " + temp2 + ", Friends: "

+ ((TwitterUser) temp2).getFollowing());

if (depth <= 0) {

// do nothing

} else {

for (int i = 0; i < depth; i++) {

Object temp = following.get(i);

getNeighborhood(temp, 0);

}

}

}
public void followUser(TwitterUser user) {

if (!following.contains(user)) {

following.add(user);

}

}

public void clearFollowing() {

following.clear();

}

public ArrayList getFollowing() {

ArrayList copy = new ArrayList();

TwitterUser[] follower = null;
for (TwitterUser t : follower); {

Object t = null;
copy.add(t);

}

return copy;

}

public int getID() {

return id;

}

public void setUserID(int newId) {

id = newId;

}

public int compareTo(TwitterUser t) {

if (id > t.getID()) {

return 1;

} else if (id < t.getID()) {

return -1;

} else {

return 0;

}

}

@Override

public int hashCode() {

final int prime = 31;

int result = 1;

result = prime * result + id;

return result;

}

@Override

public boolean equals(Object obj) {

if (this == obj)

return true;

if (obj == null)

return false;

if (getClass() != obj.getClass())

return false;

TwitterUser other = (TwitterUser) obj;

if (id != other.id)

return false;

return true;

}

public Object clone() {

try {

TwitterUser clonedUser = (TwitterUser) super.clone();

clonedUser.following = (ArrayList) following.clone();

return clonedUser;

} catch (CloneNotSupportedException e) {

return null;

}

}

public String toString() {

return Integer.toString(id);

}

// Followers begin

/*

*

* return a collection of the people who are following theuser

*/

public Collection getFollowing(TwitterUser user) {

Collection tUser = new ArrayList();

if (user.getID() == 415) {

System.out.print("nuser id: " + user.getID());

for (Object t : user.getFollowers()) {


}

return tUser;
}
return tUser;
}

private List followers = new ArrayList<>();

public void setFollowers(List f) {

for (Object i : f) {

if (!followers.contains(i))

followers.add(i);

}

}

public List getFollowers() {

return followers;

}

// Followers end

}

#

TwitterUser Class

#

import java.util.Comparator;

public abstract class UserComparator implements Comparator {

public int compare(TwitterUser o1, TwitterUser o2) {

int res = 0;

// 3. If two users have the same number of followers and arefollowing

// the same number of people, sort by user id (smallest tolargest)

if ((o1.getFollowers().size() == o2.getFollowers().size())

&& (o1.getFollowing().size() ==o2.getFollowing().size()))

res = (o1.getID() < o2.getID() ? 1 : 0);

// 2. If two users have the same number of followers, sort bythe number

// of people that user is following (largest to smallest)

if (o1.getFollowers().size() == o2.getFollowers().size())

res = o1.getFollowing().size() > o2.getFollowing().size() ? 1: 0;

// 1. Number of followers (largest to smallest)

if (o1.getFollowers().size() > o2.getFollowers().size())

res = 1;

return res;

}

}

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UserComparator Class

copper verge Dec 1, 2022, 2:49 PM

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newFileReader is returning null

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So the bufferedreader is nullpointing

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Since it's trying to read from null

hollow crown Dec 1, 2022, 2:50 PM

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Ahhh

copper verge Dec 1, 2022, 2:50 PM

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I assume you want return new FileReader(new File(filename));

hollow crown Dec 1, 2022, 2:52 PM

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now it's starting to give this error on return;

eclipse-workspace_-_ThackerJohnEdgelist_src_Driver.java_-_Eclipse_IDE_12_1_2022_9_52_13_AM.png

copper verge Dec 1, 2022, 2:53 PM

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You need to return something

copper verge Dec 1, 2022, 2:54 PM

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copper verge I assume you want `return new FileReader(new File(filename));`

👆

hollow crown Dec 1, 2022, 2:54 PM

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Ahhh

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😦

eclipse-workspace_-_ThackerJohnEdgelist_src_Driver.java_-_Eclipse_IDE_12_1_2022_9_56_50_AM.png

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huh weird

copper verge Dec 1, 2022, 3:00 PM

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I've never seen this but try removing throws clause?

hollow crown Dec 1, 2022, 3:02 PM

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I don't seem to see any throws clause in the program??

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I'm sorry I'm still learning 😭

copper verge Dec 1, 2022, 3:04 PM

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public static void main(...)** throws IOException**

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That's a "throws clause"

hollow crown Dec 1, 2022, 3:08 PM

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it's still giving out the same error sadly

copper verge Dec 1, 2022, 3:11 PM

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What's giving this error

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Looks like a tester/marking type thing

hollow crown Dec 1, 2022, 3:11 PM

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honestly I'm not sure?

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I tried giving a void to the public static the void but that just caused a problem with the return statement

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which didn't fix that issue either

copper verge Dec 1, 2022, 3:13 PM

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It shouldn't return anything hence void

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But what are you running

hollow crown Dec 1, 2022, 3:14 PM

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I'm running the Driver class

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again I do apologize, I'm still getting use to working in java

copper verge Dec 1, 2022, 3:18 PM

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Oh

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Don't return anything from main

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Remove return; from bottom of main

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Well any returns at all from any void method

hollow crown Dec 1, 2022, 3:23 PM

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Well I tried removing all returns from Main

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and that's now giving me a bunch more errors

copper verge Dec 1, 2022, 3:28 PM

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Ok well that's better

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Contrary to popular belief

hollow crown Dec 1, 2022, 3:29 PM

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Yea?

copper verge Dec 1, 2022, 3:30 PM

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What are the errors

hollow crown Dec 1, 2022, 3:31 PM

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it's the same error as last time

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now i'm just confused XD

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trying anything I can but it's still giving me this 😭

copper verge Dec 1, 2022, 3:51 PM

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Paste driver again

hollow crown Dec 1, 2022, 3:55 PM

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import java.io.BufferedReader;

import java.io.FileNotFoundException;

import java.io.FileReader;

import java.io.IOException;
import java.io.Reader;
import java.util.ArrayList;

import java.util.Collection;

import java.util.Collections;

import java.util.HashMap;

import java.util.HashSet;

import java.util.Hashtable;

import java.util.List;

import java.util.Map;

import java.util.Scanner;

import java.util.Stack;

import java.io.FileNotFoundException;

import java.io.FileReader;

import java.io.IOException;

import java.util.ArrayList;

import java.util.Collection;

import java.util.Collections;

import java.util.HashMap;

import java.util.HashSet;

import java.util.Hashtable;

import java.util.List;

import java.util.Map;

import java.util.Scanner;

import java.util.Stack;

public class Driver {

static ArrayList users = new ArrayList();

static Scanner input = new Scanner(System.in);

public static void main(String[] args) throws IOException {

String filename;

int userID;



/*

* Reading file and pulling in data

*/

/**/

System.out.print("nEnter the filename holding the user data:");

 filename = input.nextLine();//*/

filename = "social_network.edgelist";

//filename = “finalTestList.edgelist”;

System.currentTimeMillis();

System.out.println("nTesting the file input:" );

new BufferedReader(newFileReader(filename));

System.out.println("tReading data from the file…");



new Stack();

new HashSet<Object>(1000000);

System.out.println("ntThe filename" + "filename"

+  "was not found.");

System.exit(1);

/**

* System.out.println(“ntUsers:”); for (TwitterUser t: users){

* System.out.println(“tUser ” + t); }/

**/

/*

* Unit test of the getNeighborhood function

*/

System.out

.print("nTest for the getNeighborhood(user, depth)function:"

+ "ntEnter the user you would like to test: ");

userID = input.nextInt();

UserID();

System.out

.print("tEnter the depth you would like to go to in yourneighborhood: ");





}


private static Reader newFileReader(String filename) {
    // TODO Auto-generated method stub
    
}


private static TwitterUser UserID() {
    // TODO Auto-generated method stub
    
}


private static TwitterUser getUser() {
    // TODO Auto-generated method stub
    
}



// Followers && Popularity begin

/**

* Walk through the list of users and find match

*

* @param followers

*

*/

private static void mapFollowers(Stack followers) {

while (!followers.isEmpty()) {

Integer[] anEntry = (Integer[]) followers.pop();

boolean aUserId = anEntry[1] != null;

List f = findFollowersForUser(

(Stack) followers.clone(), aUserId);

System.err.println("User " + aUserId + " has " + f.size()

+ " followers.");

TwitterUser aUser = getUser();

aUser.setFollowers(f);

}

}

/**

* given a userID id find all followers in stack

*

* @param sList

* @param aUserId

* @return a list of followers

*/

private static List findFollowersForUser(Stack sList,

boolean aUserId) {

List f = new ArrayList();

while (!sList.isEmpty()) {

Integer[] ids = (Integer[]) sList.pop();

if (aUserId = ids[1] == 0) {

f.add(ids[0]);

// System.err.println(ids[0] +” : “+ ids[1]);

}

}



}

public static void test_getFollowing(TwitterUser user) {

Collection followerUsers = user.getFollowing(user);

List followers = new ArrayList();

for (Object aUser : followerUsers) {

followers.add(((TwitterUser) aUser).getID());

}

System.out.println("User " + user.getID() + " has " +followers

+ " followers. ");

}

private static Object getByPopularity(int idx) {

Collections.sort(users);

 users.get(idx);

}

// Followers && Popularity end

}

copper verge Dec 1, 2022, 3:56 PM

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newFileReader still returning null

hollow crown Dec 1, 2022, 3:58 PM

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Where if I may ask??

copper verge Dec 1, 2022, 3:59 PM

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newFileReader method still returns null

hollow crown Dec 1, 2022, 4:00 PM

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do you mean

private static Reader newFileReader(String filename)

copper verge Dec 1, 2022, 4:01 PM

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Yes

hollow crown Dec 1, 2022, 4:02 PM

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What should I do with it then???

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if you don't mind me asking 😅

hollow crown Dec 1, 2022, 4:25 PM

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??

hollow crown Dec 1, 2022, 5:38 PM

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Alright I managed to fix the problem with the file reader but now I just have to fix up the twitteruser stuff for the program

eclipse-workspace_-_Eclipse_IDE_12_1_2022_12_36_19_PM_2.png

copper verge Dec 1, 2022, 8:51 PM

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@hollow crown did you solve this?

hollow crown Dec 1, 2022, 8:52 PM

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Still no dice for me

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I got it to read out the data but I can't have it display the data

copper verge Dec 1, 2022, 8:53 PM

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ok there's a ton of crazy stuff in those classes so i'm not sure what you're trying to accomplish there

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but if you just want to read the contents of a file you can just use Files.readAllLines(new File(filename).toPath())

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this will return the lines of the file as a List<String>

hollow crown Dec 1, 2022, 8:55 PM

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alright

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let me try that then

copper verge Dec 1, 2022, 8:55 PM

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but there are loads of problems with that Driver class

hollow crown Dec 1, 2022, 8:56 PM

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I know 😭

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alright that seemed to work

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now I just need for the data to be displayed

copper verge Dec 1, 2022, 9:05 PM

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#bot-cmds message

hollow crown Dec 1, 2022, 9:09 PM

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Well not really like that

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I mean like taking the data inside of a file and display it out in the program

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Sorry being a huge bother 😭

copper verge Dec 1, 2022, 9:12 PM

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not sure what you mean

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or you can explain what you want your program to do and we can go from there

hollow crown Dec 1, 2022, 9:17 PM

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Ok, so I'm basically trying to have the program display out data from a file called social_network.edgelist and display the data from that file in the program from greatest to least as twitter followers instead of just displaying out the filename in the program

eclipse-workspace_-_ThackerJohnEdgelist_src_Driver.java_-_Eclipse_IDE_12_1_2022_4_15_14_PM.png

eclipse-workspace_-_ThackerJohnEdgelist_src_social_network.edgelist_-_Eclipse_IDE_12_1_2022_4_14_07_PM.png

copper verge Dec 1, 2022, 9:17 PM

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the code in that link prints out each line of the file, not the name of the file

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but anyway...

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#bot-cmds message

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this reads a file containing integers, sorts ascending, then prints out each one

hollow crown Dec 1, 2022, 9:22 PM

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alright

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can't really seem to get it to work with the file I already have

#a program that reads out twitter follower data but it would have an error when typing the file in