Trying to load a .txt file into JFrame (JFileChooser)

Question

So I'm in college trying to do a JFrame assignment and I'm trying to be able to load a .txt file through JFileChooser and have the text inside the file to show up in the few JTextFields that are inside this JFrame. Right now it's not working and with all the information I have from my class lectures and such, I can't find a way around this problem.

So here's the full code, the specific section I'm trying to work with is the case: "Load" section.

package assignment3;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Scanner;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.*;

public class SocialMediaList extends JFrame {

private JPanel display;
private JLabel siteNameLabel;
private JTextField siteName;
private JLabel userIDLabel;
private JTextField userID;
private JLabel contactsLabel;
private JTextField contacts;

private JPanel btns;
private JButton loadBtn;
private JButton addBtn;
private JButton saveBtn;
private JButton exitBtn;

private JPanel list;
private JList myList;

private ArrayList<SocialMedia> mediaList;

public SocialMediaList() {

    mediaList = new ArrayList();
    myList = new JList(mediaList.toArray());

    this.setLayout(new GridLayout(2,1,5,5));

    display = new JPanel();
    display.setLayout(new GridLayout(5,2,5,5));

    siteNameLabel = new JLabel("  Site Name: ");
    siteName = new JTextField(10);
    userIDLabel = new JLabel("  User ID: ");
    userID = new JTextField(10);
    contactsLabel = new JLabel("  No. of Contacts: ");
    contacts = new JTextField(10);

    display.add(siteNameLabel);
    display.add(siteName);
    display.add(userIDLabel);
    display.add(userID);
    display.add(contactsLabel);
    display.add(contacts);

    this.add(display);

    btns = new JPanel();
    btns.setLayout(new GridLayout(1,3,5,5));

    loadBtn = new JButton("Load");
    loadBtn.setActionCommand("Load");
    addBtn = new JButton("Add");
    saveBtn = new JButton("Save");
    exitBtn = new JButton("Exit");

    btns.add(loadBtn);
    btns.add(addBtn);
    btns.add(saveBtn);
    btns.add(exitBtn);

    this.add(btns);

    list = new JPanel();
    list.setLayout(new FlowLayout());
    JScrollPane myScrollPane = new JScrollPane(myList);
    list.add(myScrollPane);

    setLayout(new BorderLayout());
    this.add(display,BorderLayout.NORTH);
    this.add(btns,BorderLayout.CENTER);
    this.add(list,BorderLayout.SOUTH);

    ButtonListeners buttonListener = new ButtonListeners();
    loadBtn.addActionListener(buttonListener);
    addBtn.addActionListener(buttonListener);
    saveBtn.addActionListener(buttonListener);
    exitBtn.addActionListener(buttonListener);
}

public static void main(String[] args) {
    SocialMediaList list = new SocialMediaList();
    list.setTitle("Assignment #3");
    list.setSize(600,350);
    list.setLocationRelativeTo(null);
    list.setVisible(true);
    list.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

class ButtonListeners implements ActionListener {

    @Override
    public void actionPerformed(ActionEvent e) {
        switch(e.getActionCommand()) {

            case "Load":
                File file;
                try {

                    JFileChooser chooser = new JFileChooser();

                    if (chooser.showOpenDialog(null) == JFileChooser.APPROVE_OPTION) {

                        file = chooser.getSelectedFile();

                        Scanner input = new Scanner(file);

                        while (input.hasNextLine()) {
                            SocialMedia account = mediaList.get(myList.getSelectedIndex());
                            siteName.setText(account.getSiteName());
                            userID.setText(account.getUserID());
                            contacts.setText(String.valueOf(account.getContacts()));

                            myList.setListData(mediaList.toArray());
                            add(siteName);
                            add(userID);
                            add(contacts);

                            if (mediaList.size() > 0) {
                                myList.setSelectedIndex(0);
                            }
                        }


                    }

                } catch (FileNotFoundException ex) {
                    Logger.getLogger(SocialMediaList.class.getName()).log(Level.SEVERE, null, ex);
                }


            case "Add": 
                String s = siteName.getText();
                String u = userID.getText();
                int c = Integer.valueOf(contacts.getText());
                SocialMedia mySocialMedia = new SocialMedia();
                mySocialMedia.setSiteName(s);
                mySocialMedia.setUserID(u);
                mySocialMedia.setContacts(c);

                mediaList.add(mySocialMedia);
                myList.setListData(mediaList.toArray());
                break;

            case "Save":
        try {
            FileWriter writer = new FileWriter("socialMedia2.txt");
            writer.write(mediaList.toString());
            writer.write(myList.toString());
            writer.close();
        } catch (IOException ex) {
            Logger.getLogger(SocialMediaList.class.getName()).log(Level.SEVERE, null, ex);
        }

            case "Exit":
                System.exit(0);
        }
    }
}

class ExitListener implements ActionListener {

    @Override
    public void actionPerformed(ActionEvent e) {
        System.exit(0);
    }
}
}