Can you write to files with an applet or what?

Question

Hi I can't get the bufferwriter to output any text to a file. Not sure if this is because I'm using an applet? I wouldn't assume so, but any help would be appreciated
The problem area is :
private boolean registerNewUser()
        FileOutputStream writer;
        try
            BufferedWriter out = new BufferedWriter(new FileWriter("logins.txt"));
            out.write(regUserField.getText());
            char [] tempPass = regPasswordField.getPassword();
            String tempString = tempPass.toString();
            out.write("\n" + tempString);
            out.close();
        catch(IOException e)
            System.out.println("Writing file error.");
            System.exit(0);
        int intSS = Integer.parseInt(regSSNField.getText());
        currentUserAccount = new Account(regNameField.getText(), intSS);
        return true;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.*;
import javax.swing.*;
import javax.swing.Icon;
import javax.swing.JApplet;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import java.lang.*;
import java.io.*;
import java.util.*;
public class JBank extends JApplet implements ActionListener
    private static double totalMoney = 0;
    private static final String BANK_MENUITEM = "Bank";
    private static final String NEW_ACCT_MENUITEM = "New Account";
    private static final String OPEN_ACCT_MENUITEM = "Open Account";
    private static final String DELETE_ACCT_MENUITEM = "Delete Account";
    private static final String TRANSFER_ACCT_MENUITEM = "Account transfer";
    private static final String WITHDRAW_ACCT_MENUITEM = "Withdraw Funds";
    private static final String DEPOSIT_ACCT_MENUITEM = "Deposit Funds";
    private static final String OVERVIEW_ACCT_MENUITEM = "Overview of Accounts";
    private static final String CHECKING_RADIO_BUTTON = "new account checking";
    private static final String SAVINGS_RADIO_BUTTON = "new account savings";
    private static final String RETIREMENT_RADIO_BUTTON = "new account retirement";
    private static final String LOGIN_BUTTON = "login";
    private static final String REGISTER_BUTTON = "register";
    private static final String CANCEL_BUTTON = "cancel";
    private static final String NEW_ACCT_OK_BUTTON = "new account ok";
    private static final String NEW_ACCT_CANCEL_BUTTON = "new account cancel";
    private static final String NEW_USER_REGISTER_BUTTON = "new user registration";
    private static final String MAIN_TITLE_TEXT = "JBank - A Comp 285 Project";
    private Container contentPane = getContentPane();
    private JFrame loginFrame = new JFrame();
    private JFrame registrationFrame = new JFrame();
    private JFrame newAccountFrame = new JFrame();
    private JLabel title;
    private JTextField loginField;
    private JPasswordField passwordField;
    private JTextField regNameField;
    private JTextField regSSNField;
    private JTextField regUserField;
    private JTextField initialMoneyField;
    private JPasswordField regPasswordField;
    boolean trueUser = false;
    boolean savingsSelected = false;
    boolean checkingSelected = false;
    boolean retirementSelected = false;
    Account currentUserAccount;
    public void init()
        //Login First
        loginFrame();
        contentPane.setLayout(new BorderLayout());
        // background color: lightblue
        float red = 0f;
        float blue = .3f;
        float green = .2f;                                     // Java sees double, must specify a suffix of f to
        float alpha = .05f;                                    //create float since
        Color lightBlue = new Color(red, green, blue, alpha); //<-- constructor requires floats
        contentPane.setBackground(lightBlue);
        // Menu
        JMenuBar jBar = new JMenuBar();
        JMenu bankMenu = new JMenu(BANK_MENUITEM);
        JMenuItem b;
        b = new JMenuItem(NEW_ACCT_MENUITEM);
        b.addActionListener(this);
        bankMenu.add(b);
        b = new JMenuItem(OPEN_ACCT_MENUITEM);
        b.addActionListener(this);
        bankMenu.add(b);
        b = new JMenuItem(DELETE_ACCT_MENUITEM);
        b.addActionListener(this);
        bankMenu.add(b);
        b = new JMenuItem(TRANSFER_ACCT_MENUITEM);
        b.addActionListener(this);
        bankMenu.add(b);
        b = new JMenuItem(OVERVIEW_ACCT_MENUITEM);
        b.addActionListener(this);
        bankMenu.add(b);
        jBar.add(bankMenu);
        setJMenuBar(jBar);
        // Title JBankset
        title = new JLabel(MAIN_TITLE_TEXT);
        contentPane.add(title);
    public void actionPerformed(ActionEvent arg0)
        String command = arg0.getActionCommand();
        if (command.equals(BANK_MENUITEM))
            title.setText(MAIN_TITLE_TEXT + " " +
                    BANK_MENUITEM);
        else if (command.equals(NEW_ACCT_MENUITEM))
            title.setText(MAIN_TITLE_TEXT + " " +
                    NEW_ACCT_MENUITEM);
            newAccountFrame();
        else if (command.equals(OPEN_ACCT_MENUITEM))
            title.setText(MAIN_TITLE_TEXT + " " +
                    OPEN_ACCT_MENUITEM);
        else if (command.equals(DELETE_ACCT_MENUITEM))
            title.setText(MAIN_TITLE_TEXT + " " +
                    DELETE_ACCT_MENUITEM);
        else if (command.equals(TRANSFER_ACCT_MENUITEM))
            title.setText(MAIN_TITLE_TEXT + " " +
                    TRANSFER_ACCT_MENUITEM);
        else if (command.equals(OVERVIEW_ACCT_MENUITEM))
            title.setText(MAIN_TITLE_TEXT + " " +
                    OVERVIEW_ACCT_MENUITEM);
        else if (command.equals(LOGIN_BUTTON))
            Scanner loginFile = null;
            String currentFileLoginName;
            String triedLogin = loginField.getText();
            try
               loginFile = new Scanner(new FileInputStream("logins.txt"));
            catch(FileNotFoundException e)
                System.out.println("Internal Error");
                System.exit(0);
            do
               currentFileLoginName = loginFile.nextLine();
               if  (processLogin(currentFileLoginName, triedLogin, loginFile)) //Send Logins&File | Return boolean
                   loginFile.close(); //Close File
                   break; //Login true. Break out of while loop
            while (loginFile.hasNextLine() == true);
        else if (command.equals(REGISTER_BUTTON))
            registrationFrame();
        else if (command.equals(NEW_USER_REGISTER_BUTTON))
            registrationFrame.setVisible(false);
            if (checkFields() == false)
                registrationFrame.dispose();
                registrationFrame();
            else
            registerNewUser();
        else if (command.equals(CHECKING_RADIO_BUTTON))
            savingsSelected = false;
            checkingSelected = true;
            retirementSelected = false;
        else if (command.equals(SAVINGS_RADIO_BUTTON))
            savingsSelected = true;
            checkingSelected = false;
            retirementSelected = false;
        else if(command.equals(RETIREMENT_RADIO_BUTTON))
            savingsSelected = false;
            checkingSelected = false;
            retirementSelected = true;
        else if (command.equals(NEW_ACCT_OK_BUTTON))
            double doubleInitialMoney = Double.parseDouble(initialMoneyField.getText());
            if (savingsSelected)
                currentUserAccount.registerAccount("savings");
                currentUserAccount.deposit("savings", doubleInitialMoney);
            if (checkingSelected)
                currentUserAccount.registerAccount("checking");
                currentUserAccount.deposit("checking", doubleInitialMoney);
            if (retirementSelected)
                currentUserAccount.registerAccount("register");
                currentUserAccount.deposit("retirement", doubleInitialMoney);
            newAccountFrame.dispose();
    private void loginFrame()
        loginFrame.setTitle("JBank -- Login Required");
        loginFrame.setDefaultLookAndFeelDecorated(true);
        loginFrame.setBounds(400,350,225,130);
        JTextField login = new JTextField("User ID");
        JTextField password = new JTextField("Password");
        loginFrame.setLayout(new GridLayout(0,2));
        //Button Panel
        JPanel buttonPanel = new JPanel();
        buttonPanel.setLayout(new GridLayout(4,0));
        JLabel space = new JLabel("                   ");
        JButton okButton = new JButton("Login");
        okButton.isDefaultButton();
        okButton.setVerticalTextPosition(AbstractButton.CENTER);
        JButton register = new JButton("Register");
        register.setVerticalTextPosition(AbstractButton.CENTER);
        okButton.setActionCommand(LOGIN_BUTTON);
        register.setActionCommand(REGISTER_BUTTON);
        okButton.addActionListener(this);
        register.addActionListener(this);
        buttonPanel.add(okButton);
        buttonPanel.add(space);
        buttonPanel.add(register);
        buttonPanel.add(space);
        //Text Panel
        JPanel textPanel = new JPanel();
        textPanel.setLayout(new GridLayout(4,0));
        JLabel userIDLabel = new JLabel("User ID:");
        JLabel passwordLabel = new JLabel("Password:");
        loginField = new JTextField(14);
        passwordField = new JPasswordField(14);
        textPanel.add(userIDLabel);
        textPanel.add(loginField);
        textPanel.add(passwordLabel);
        textPanel.add(passwordField);
        loginFrame.add(textPanel);
        loginFrame.add(buttonPanel);
        loginFrame.setVisible(true);
    private void registrationFrame()
        loginFrame.setVisible(false);
        //Registration's Frame
        registrationFrame.setTitle("JBank -- Registration");
        registrationFrame.setDefaultLookAndFeelDecorated(true);
        registrationFrame.setBounds(400,350,300,300);
        registrationFrame.setLayout(new BorderLayout());
        //Buttons
        JButton registerButton = new JButton("Register");
        JButton cancelButton = new JButton("Cancel");
        //Text Fields
        regNameField = new JTextField(20);
        regSSNField = new JTextField(8);
        regUserField = new JTextField(14);
        regPasswordField = new JPasswordField(14);
        //Labels
        JLabel nameLabel = new JLabel("Name:  ");
        JLabel ssnLabel = new JLabel("Social Security: ");
        JLabel newUserLabel = new JLabel("Desired User ID: ");
        JLabel newPasswordLabel = new JLabel("Desired Password: ");
        //Top Panel
        JPanel newUserFieldsPanel = new JPanel();
        newUserFieldsPanel.setLayout(new GridLayout(8,0));
        //Bottom Panel
        JPanel newUserButtonsPanel = new JPanel();
        newUserButtonsPanel.setLayout(new GridLayout(0,2));
        //Add
        newUserFieldsPanel.add(nameLabel);
        newUserFieldsPanel.add(regNameField);
        newUserFieldsPanel.add(ssnLabel);
        newUserFieldsPanel.add(regSSNField);
        newUserFieldsPanel.add(newUserLabel);
        newUserFieldsPanel.add(regUserField);
        newUserFieldsPanel.add(newPasswordLabel);
        newUserFieldsPanel.add(regPasswordField);
        newUserButtonsPanel.add(registerButton);
        newUserButtonsPanel.add(cancelButton);
        registrationFrame.add(newUserFieldsPanel, BorderLayout.CENTER);
        registrationFrame.add(newUserButtonsPanel, BorderLayout.SOUTH);
        //Action Listeners
        registerButton.setActionCommand(NEW_USER_REGISTER_BUTTON);
        cancelButton.setActionCommand(CANCEL_BUTTON);
        registerButton.addActionListener(this);
        cancelButton.addActionListener(this);
        registrationFrame.setVisible(true);
    private void newAccountFrame()
        //New Account Frame
        newAccountFrame.setTitle("Create New Account");
        newAccountFrame.setDefaultLookAndFeelDecorated(true);
        newAccountFrame.setBounds(400,350,300,300);
        newAccountFrame.setLayout(new BorderLayout());
        //Buttons
        JButton newAcctOkButton = new JButton("OK");
        JButton newAcctCancelButton = new JButton("Cancel");
        //Radio Buttons
        JRadioButton checkingOption = new JRadioButton("Checking Account");
        JRadioButton savingsOption = new JRadioButton("Savings Account");
        JRadioButton retirementOption = new JRadioButton("Retirement Account");
        //Group 'em
        ButtonGroup accountSettings = new ButtonGroup();
        accountSettings.add(checkingOption);
        accountSettings.add(savingsOption);
        accountSettings.add(retirementOption);
        //Text Fields
        initialMoneyField = new JTextField("0", 8);
        //Labels
        JLabel depositLabel = new JLabel("Initial Deposit:  ");
        JLabel optionLabel = new JLabel("What kind of account would \n"
        + "you like to create?");
        //Top Panel
        JPanel newAcctOptionsPanel = new JPanel();
        newAcctOptionsPanel.setLayout(new GridLayout(4,0));
        //Bottom Panel
        JPanel newAcctTextPanel = new JPanel();
        newAcctTextPanel.setLayout(new GridLayout(2,2));
        //Add
        newAcctOptionsPanel.add(optionLabel);
        newAcctOptionsPanel.add(checkingOption);
        newAcctOptionsPanel.add(savingsOption);
        newAcctOptionsPanel.add(retirementOption);
        newAcctTextPanel.add(depositLabel);
        newAcctTextPanel.add(initialMoneyField);
        newAcctTextPanel.add(newAcctOkButton);
        newAcctTextPanel.add(newAcctCancelButton);
        newAccountFrame.add(newAcctOptionsPanel, BorderLayout.CENTER);
        newAccountFrame.add(newAcctTextPanel, BorderLayout.SOUTH);
        //Action Listeners
        checkingOption.setActionCommand(CHECKING_RADIO_BUTTON);
        savingsOption.setActionCommand(SAVINGS_RADIO_BUTTON);
        retirementOption.setActionCommand(RETIREMENT_RADIO_BUTTON);
        checkingOption.addActionListener(this);
        savingsOption.addActionListener(this);
        retirementOption.addActionListener(this);
        newAcctOkButton.setActionCommand(NEW_ACCT_OK_BUTTON);
        newAcctCancelButton.setActionCommand(NEW_ACCT_CANCEL_BUTTON);
        newAcctOkButton.addActionListener(this);
        newAcctCancelButton.addActionListener(this);
        newAccountFrame.setVisible(true);
    private boolean checkFields()
        //Check Name Field
        String triedName = regNameField.getText();
        if (triedName.length() == 0)
            JOptionPane.showMessageDialog(null,
            "Empty Name Field. Try Again.",
            "Error Message",
            JOptionPane.ERROR_MESSAGE);
            return false;
        //Check SSN
        String triedSS = regSSNField.getText();
        int parsedSS = 0;
        try
            parsedSS = Integer.parseInt(triedSS);
        catch(Exception e)
            JOptionPane.showMessageDialog(null,
            "Numbers only in Social Security Field!\n Try Again.",
            "Error Message",
            JOptionPane.ERROR_MESSAGE);
            return false;
        if (triedSS.length() < 8)
            JOptionPane.showMessageDialog(null,
            "Social Security Number is not 8 Digits.\n Try Again.",
            "Error Message",
            JOptionPane.ERROR_MESSAGE);
            return false;
        //Check User ID
        String triedUser = regUserField.getText();
        if (triedUser.length() < 6)
            JOptionPane.showMessageDialog(null,
            "Desired User ID too short.\n Try Again",
            "Error Message",
            JOptionPane.ERROR_MESSAGE);
            return false;
        //Check Password
        char[] triedPassword = regPasswordField.getPassword();
        String stringPassword = triedPassword.toString();
        if (stringPassword.length() < 6)
            JOptionPane.showMessageDialog(null,
            "Desired Password Too Short. \n Try Again.",
            "Error Message",
            JOptionPane.ERROR_MESSAGE);
            return false;
        return true;
    private boolean registerNewUser()
        FileOutputStream writer;
        try
            BufferedWriter out = new BufferedWriter(new FileWriter("logins"));
            out.write(regUserField.getText());
            char [] tempPass = regPasswordField.getPassword();
            String tempString = tempPass.toString();
            out.write("\n" + tempString);
            out.close();
        catch(IOException e)
            System.out.println("Writing file error.");
            System.exit(0);
        int intSS = Integer.parseInt(regSSNField.getText());
        currentUserAccount = new Account(regNameField.getText(), intSS);
        return true;
    private boolean processLogin(String currentFileLoginName, String triedLogin, Scanner loginFile)
        char[] userPassword = passwordField.getPassword();
        if (currentFileLoginName.equals(triedLogin))
            String currentFilePassword = loginFile.nextLine(); //Login recognized, go to next line for password
            char[] charPassword = currentFilePassword.toCharArray();
            if (charPassword.length == userPassword.length) //Password Lengths match?
                if(Arrays.equals(userPassword, charPassword)) //Do characters match?
                    trueUser = true;
                    loginFrame.dispose();
                    return true;
            else
                JOptionPane.showMessageDialog(null, //Notify User of Incorrect password
                 "Invalid password. Try again.",
                 "Error Message",
                 JOptionPane.ERROR_MESSAGE);
                 return false;
        else
            JOptionPane.showMessageDialog(null, //Notify user of unrecognized login
            "Unknown User ID. Try again\n or Register.",
            "Error Message",
            JOptionPane.ERROR_MESSAGE);
            return false;
        return false;
    private class Account
    private String name;
    private int ssn;
    private double totalUserMoney;
    private boolean checking = false;
    private boolean savings = false;
    private boolean retirement = false;
    private double checking_holdings;
    private double savings_holdings;
    private double retirement_holdings;
   public Account(String userName, int ss)
       name = userName;
       ssn = ss;
    public int getSSN()
        return ssn;
    public double getTotalUserMoney()
        return totalUserMoney;
    public boolean getUserAccounts(String type)
       if (type.equals("checking"))
           if (checking == false)
           return false;
           else
           return true;
        if (type.equals("savings"))
            if (savings == false)
            return false;
            else
            return true;
        if (type.equals("retirement"))
            if (retirement == false)
            return false;
            else
            return true;
        return false;
    public void registerAccount(String type)
        if (type.equals("checking"))
        checking = true;
        else if (type.equals("savings"))
        savings = true;
        else if (type.equals("retirement"))
        retirement = true;
        else
        System.out.println("Internal error"); //Should not reach here
    public boolean withdraw(String type, Double moneyAmount)
        if(getUserAccounts(type))
            if(type.equals("checking"))
                if (moneyAmount > checking_holdings)
                    JOptionPane.showMessageDialog(null,"Insufficient holdings in checking account");
                else
                    checking_holdings -= moneyAmount;
                    totalUserMoney -= moneyAmount;
                    return true;
            if(type.equals("savings"))
                if (moneyAmount > checking_holdings)
                    JOptionPane.showMessageDialog(null,"Insufficient holdings in savings account");
                else
                    savings_holdings -= moneyAmount;
                    totalUserMoney -= moneyAmount;
                    return true;
            if(type.equals("retirement"))
                if (moneyAmount > checking_holdings)
                    JOptionPane.showMessageDialog(null,"Insufficient holdings in retirement account");
                else
                    retirement_holdings -= moneyAmount;
                    totalUserMoney -= moneyAmount;
                    return true;
        else
            JOptionPane.showMessageDialog(null,"No such account exists");
            return false;
    public boolean deposit(String type, Double moneyAmount)
        if(getUserAccounts(type))
            if(type.equals("checking"))
                checking_holdings += moneyAmount;
                totalUserMoney += moneyAmount;
                return true;
            if(type.equals("savings"))
                savings_holdings += moneyAmount;
                totalUserMoney += moneyAmount;
                return true;
            if(type.equals("retirement"))
                retirement_holdings += moneyAmount;
                totalUserMoney += moneyAmount;
                return true;
        else
            JOptionPane.showMessageDialog(null,"No such account exists");
            return false;
    public void deleteAccount(String type)
        if (type.equals("checking"))
            totalUserMoney -= checking_holdings;
            checking = false;
        if (type.equals("savings"))
            totalUserMoney -= savings_holdings;
            savings = false;
        if (type.equals("retirement"))
            totalUserMoney -= retirement_holdings;
            retirement = false;
    public void showAccountInfo()
        if (checking == true && savings == true && retirement == true)
        System.out.println(name + "'s Accounts: " + "\nChecking Account: $" + checking_holdings
        + "\nSavings Account: $" + savings_holdings + "\nRetirement Account: $" +
        retirement_holdings + "\n\nTotal: $" + totalUserMoney);
    public void showAccountInfo(String type)
        System.out.println(name + " ");
}

Answer 1

In the future, do not post eleventeenkathousand lines of code. No one is going to read it all and - quite frankly - no one really cares.
As for the issue at hand, whenever you are going to access the file system, a remote server, access the clipboard and a handful of other "security" related issues, you must sign your applet.
Google for sun's tutorial on signing applets.