MailJava in a new Thread - multithreading

Question

I try to get emails from csv file and start mailing process. Everything works fine if I do it in the main thread. But if I start a new thread and try to do it threre it gives me NullPointer on this line:
email.sendEmail(readerEmail.myList, mailingSubject, mailingText);
For some reason it cannot get a list of emails.
Full code is here:
package com.company;
import javax.mail.MessagingException;
import javax.swing.*;
import static com.company.MainFormAppearance.mailingSubject;
import static com.company.MainFormAppearance.mailingText;
public class NewThead implements Runnable {
public JTextArea jTextAreaStatus;
public Reader readerEmail;
private boolean doStop = false;
public synchronized void doStop() {
this.doStop = true;
}
private synchronized boolean keepRunning() {
return this.doStop == false;
}
#Override
public void run() {
while (keepRunning()){
Email email = new Email();
try {
email.sendEmail(readerEmail.myList, mailingSubject, mailingText);
} catch (MessagingException e) {
e.printStackTrace();
}
}
jTextAreaStatus.setText("completed");
}
}
Main class:
public class MainFormAppearance {
private JTextArea jTextAreaText;
private JTextArea jTextAreaSubject;
private JTextArea jTextAreaEmail;
private JTextArea jTextAreaStatus;
private JLabel blueLabel;
private JLabel copyRightLabel;
public JButton parceButton;
private JButton mailButton;
private JButton stopButton;
private String FILE_PATH_TEXT = "c:/Users/R2D2/Desktop/Main.txt";
private String FILE_PATH_SUBJECT = "c:/Users/R2D2/Desktop/Subject.txt";
public String CsvEmailsPath = "C:\\Users\\R2D2\\Desktop\\Emailstest.csv";
public String CsvBusinessesPath = "C:\\Users\\R2D2\\Desktop\\Businessestest.csv";
public static String mailingText = null;
public static String mailingSubject = null;
public Reader readerEmail;
public Reader readerBusiness;
public JPanel createContentPanel() {
JPanel totalGui = new JPanel();
totalGui.setLayout(null);
totalGui.setBackground(new Color(72, 209, 204));
jTextAreaText = new JTextArea();
jTextAreaSubject = new JTextArea();
jTextAreaEmail = new JTextArea();
jTextAreaStatus = new JTextArea();
blueLabel = new JLabel("Java Mailing Program");
copyRightLabel = new JLabel("\u00a9" + " Alex B - 2018");
parceButton = new JButton("Upload");
mailButton = new JButton("!Start!");
stopButton = new JButton("Stop");
readerEmail = new Reader();
readerBusiness = new Reader();
NewThead newThead = new NewThead();
Thread thread = new Thread(newThead);
//set program label
copyRightLabel.setLocation(10, 230);
copyRightLabel.setSize(400, 20);
copyRightLabel.setFont(new Font("Courier New", Font.ITALIC, 12));
copyRightLabel.setHorizontalAlignment(SwingConstants.CENTER);
totalGui.add(copyRightLabel);
//set program label
blueLabel.setLocation(10, 10);
blueLabel.setSize(400, 20);
blueLabel.setFont(new Font("Courier New", Font.ITALIC, 15));
blueLabel.setHorizontalAlignment(SwingConstants.CENTER);
totalGui.add(blueLabel);
//set Button 1 and click
parceButton.setLocation(270, 50);
parceButton.setSize(100, 30);
totalGui.add(parceButton);
parceButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
//parce data from files to Strings
mailingText = readLineByLineJava8(FILE_PATH_TEXT);
mailingSubject = readLineByLineJava8(FILE_PATH_SUBJECT);
try {
readerEmail.readCsvFile(CsvEmailsPath);
readerBusiness.readCsvFile(CsvBusinessesPath);
} catch (IOException e1) {
e1.printStackTrace();
}
if (isNullOrEmpty(mailingText)) {
jTextAreaText.setText("Text is empty! Check it!!!");
} else {
jTextAreaText.setText("***Text is Ready***");
}
if (isNullOrEmpty(mailingSubject)) {
jTextAreaSubject.setText("Subject is empty! Check it!!!");
} else {
jTextAreaSubject.setText("***Subject is Ready***");
}
}
});
//set Button 2 and click
mailButton.setLocation(270, 100);
mailButton.setSize(100, 30);
totalGui.add(mailButton);
mailButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
thread.start();
}
});
stopButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
newThead.doStop();
jTextAreaStatus.setText("Stopped");
}
});
stopButton.setLocation(270, 150);
stopButton.setSize(100, 30);
totalGui.add(stopButton);
jTextAreaText.setLocation(20, 52);
jTextAreaText.setSize(200, 16);
jTextAreaText.setFont(new Font("Courier New", Font.ITALIC, 12));
jTextAreaText.setBorder(BorderFactory.createLineBorder(new Color(169, 169, 169)));
totalGui.add(jTextAreaText);
jTextAreaSubject.setLocation(20, 82);
jTextAreaSubject.setSize(200, 16);
jTextAreaSubject.setFont(new Font("Courier New", Font.ITALIC, 12));
jTextAreaSubject.setBorder(BorderFactory.createLineBorder(new Color(169, 169, 169)));
totalGui.add(jTextAreaSubject);
jTextAreaEmail.setLocation(20, 112);
jTextAreaEmail.setSize(200, 16);
jTextAreaEmail.setFont(new Font("Courier New", Font.ITALIC, 12));
jTextAreaEmail.setBorder(BorderFactory.createLineBorder(new Color(169, 169, 169)));
totalGui.add(jTextAreaEmail);
jTextAreaStatus.setLocation(20, 182);
jTextAreaStatus.setSize(200, 16);
jTextAreaStatus.setFont(new Font("Courier New", Font.ITALIC, 12));
jTextAreaStatus.setBorder(BorderFactory.createLineBorder(new Color(169, 169, 169)));
totalGui.add(jTextAreaStatus);
totalGui.setOpaque(true);
return totalGui;
}
public static boolean isNullOrEmpty(String str) {
if (str != null && !str.isEmpty())
return false;
return true;
}
}
Class that reads emails from csv (should be correct):
package com.company;
import au.com.bytecode.opencsv.CSVReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.LinkedList;
public class Reader {
public CSVReader reader;
public LinkedList myList;
public void readCsvFile(String path) throws IOException {
try {
reader = new CSVReader(new FileReader(path));
String[] column;
myList = new LinkedList<>();
LinkedList <String> map;
while ((column = reader.readNext()) != null) {
map = new LinkedList<String>();
map.add(column[0]);
myList.add(String.valueOf(map).replace("[","").replace("]",""));
//myList.add(String.valueOf(map));
}
reader.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
Why i do it in another thread? Because I want to have a chance to stopp mailing process by clicking in stop button and killing a new thread.