What is wrong with this java

Question

Hi guys
I have a little experience with java
I have to classes LoginScreen and newUser. LoginScreen calss reads data from text file which is user name and passwords then extracts usernames and load them to Comobox .in the first position of the Comobox I Inserted “Create New Profile” string .When the user click on it another Screen will appear which is instance of the newUser class .And that will allow new user to enter his name and press Ok button to confirm the operation ,then the new Screen will be closed .When that happen I want new user name be inserted into the Combox in LoginScreen.Anybody has any clue why the code below does not work correctly .
import javax.swing.*;
import java.awt.*;
public class newUser extends javax.swing.JFrame {
private String allowed = "abcdefghijklmnopqrstuvwxyz_- ";
LoginScreen loginScreen;
private Dimension loginSize;
/** Creates new form AddnewUser */
public newUser() {
initComponents();
setLocationRelativeTo(null);
loginScreen =new LoginScreen();
private void initComponents() {
setLayout(new FlowLayout());
setSize(300, 100);
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setTitle("AddNew User");
setResizable(true);
jTextField1 = new javax.swing.JTextField();
loginSize = new Dimension(110, 25);//125
jTextField1.setPreferredSize(loginSize);
this.add(jTextField1);
jButton1 = new JButton("OK");
jButton1.setPreferredSize(loginSize);
this.add(jButton1);
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                        
String addNew = jTextField1.getText();
String passwors1 ="123";
//here when I invoke postAdd in LoginScreen class
loginScreen.postAdd(addNew,passwors1);
loginScreen.setEnabled(true);
private javax.swing.JButton jButton1;
private javax.swing.JTextField jTextField1;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.io.*;
import java.util.*;
import java.awt.*;
import javax.swing.*;
public class LoginScreen extends javax.swing.JFrame {
private ArrayList<String> newUser = new ArrayList<String>();
private Dimension loginSize;
String choice="";
/** Creates new form LoginScreen */
public LoginScreen() {
initComponents();//**
setLocationRelativeTo(null);
initProfiles();
private void initComponents() {//**
setLayout(new FlowLayout());
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setSize(300, 100);
loginSize = new Dimension(110, 25);
jComboBox1 = new javax.swing.JComboBox();
jComboBox1.setPreferredSize(loginSize);
jButton1 = new javax.swing.JButton("OK");
jButton1.setPreferredSize(loginSize);
this.add(jComboBox1);
this.add(jButton1);
jComboBox1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jComboBox1ActionPerformed(evt);
jButton1.setText("OK");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
* Extracts the profiles from the profile.txt file and inputs them within the combo box.
* Called from the constructor of this class.
void initProfiles()
try {
File f = new File("c:\\JavaPrjImplemention\\javaProject\\profiles.txt");
Scanner filein;
filein = new Scanner(f);
newUser.add("Create New Profile");
while (filein.hasNext())
String temp = filein.nextLine();
newUser.add(temp);
filein.close();
jComboBox1.insertItemAt(newUser.get(0), 0);
for (int i = 1; i < newUser.size(); i++)
{    if(!(newUser.get(i).charAt(0) == '*'))
jComboBox1.insertItemAt(newUser.get(i), (i+1)/2);
catch (FileNotFoundException ex)
Logger.getLogger(LoginScreen.class.getName()).log(Level.SEVERE, null, ex);
//here when I inserted the new user to the combox
void postAdd(String addNew ,String addPassword) {
try
newUser.add(addNew);
String password='*'+addPassword;
newUser.add(password);
int len = newUser.size()/2 ;
jComboBox1.insertItemAt(addNew,len);
PrintWriter filepw;
filepw = new PrintWriter("c:\\JavaPrjImplemention\\javaProject\\profiles.txt");
for (int i = 1; i < newUser.size(); i++)
filepw.println(newUser.get(i));
filepw.close();
catch (FileNotFoundException ex)
Logger.getLogger(LoginScreen.class.getName()).log(Level.SEVERE, null, ex);
private void jComboBox1ActionPerformed(java.awt.event.ActionEvent evt) {
JComboBox cb = (JComboBox)evt.getSource();
choice = (String)cb.getSelectedItem();
//here new user will be allwoed to enter
//his name by invoking newUser calss
if (choice.equals("Create New Profile"))
newUser addNewuser=new newUser();
addNewuser.setVisible(true);
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                        
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new LoginScreen().setVisible(true);
private javax.swing.JButton jButton1;
private javax.swing.JComboBox jComboBox1;
}

Answer 1

1. You have to precisely define "does not work."
2. You have to use code tags to make your code readable. Re-paste it from the original source (not from you post here), highlight it, and clicke the CODE button above the message entry box.