Changing password logic - old password, new password, retype password

Question

I have a MainFrame class which has a Change Password button. The action for the button is:
          // Change password
          aListener = new ActionListener() {
               public void actionPerformed(ActionEvent e) {
                   ChangeMyPassword cmp = new ChangeMyPassword(
                                 MainFrame.this);
                   cmp.dispose();          
          changePasswordButton.addActionListener(aListener);When the user press the Change Password button, it pass control to the ChangeMyPassword class which as a submit button and a cancel button. When the user press the submit button, it should validate the old password (i.e. compare it to the password in the text file), validate the new password match the retype password:
          // submit button
          ActionListener aListener = new ActionListener() {
               public void actionPerformed(ActionEvent e) {
                    // Retrieve the password.
                    char[] pw = oldPasswordField.getPassword();
                    oldPassword = new String(pw).trim();
                    pw = newPasswordField.getPassword();
                    newPassword = new String(pw).trim();
                    pw = retypePasswordField.getPassword();
                    retypePassword = new String(pw).trim();
                    // Hide, but don't dispose of, this window ...
                    // we need to give the client code a chance to
                    // retrieve the user's typed response via
                    // the getPassword() method first.
                    ChangeMyPassword.this.setVisible(false);
          submitButton.addActionListener(aListener);I have a Student class which compare the old password with the password in the text file. The student class constructor takes the student id to identify which student text file it should call.
The problem is that the ChangeMyPassword does not know about student id (because I am getting these from the text field in MainFrame class). So how can I call the validatePassword method in Student class?
     public boolean validatePassword(String pw) {
          if (pw == null) return false;
          if (pw.equals(password)) return true;
          else return false;
     }

Answer 1

I don�t understand why it does not update the text file with the new password.
The submit button has the action in ChangeMyPassword class:
          // submit button
          ActionListener aListener = new ActionListener() {
               public void actionPerformed(ActionEvent e) {
                    // Retrieve the password.
                    char[] pw = oldPasswordField.getPassword();
                    oldPassword = new String(pw).trim();
                    pw = newPasswordField.getPassword();
                    newPassword = new String(pw).trim();
                    pw = retypePasswordField.getPassword();
                    retypePassword = new String(pw).trim();
                    Student theStudent = new Student(id);
                    if(theStudent.validatePassword(oldPassword)){
                        if(validateChangePassword()){
                             // write the new password to file
                             theStudent.setPassword(getNewPassword());
                             // Let the user know that the
                             // password succeeded.
                             JOptionPane.showMessageDialog(null,
                              "Password change successfully.",
                              "Password Changed",
                              JOptionPane.INFORMATION_MESSAGE);
                        }else{
                             JOptionPane.showMessageDialog(null,
                                        "You have used an invalid user name or password; please try again.",
                                        "Authentication failed",
                                        JOptionPane.WARNING_MESSAGE);
                   }else{
                        JOptionPane.showMessageDialog(null,
                                   "You have used an invalid user name or password; please try again.",
                                   "Authentication failed",
                                   JOptionPane.WARNING_MESSAGE);                        
                    // Hide, but don't dispose of, this window ...
                    // we need to give the client code a chance to
                    // retrieve the user's typed response via
                    // the getPassword() method first.
                    ChangeMyPassword.this.setVisible(false);
          submitButton.addActionListener(aListener);Validate password method in Student class:
     public boolean validatePassword(String pw) {
          if (pw == null) return false;
          if (pw.equals(password)) return true;
          else return false;
     }Validate change password method in ChangeMyPassword class:
     public boolean validateChangePassword(){
          if(newPassword.equals(retypePassword))return true;
          else return false;
     }When the user press the Change Password button the action performed in the MainFrame class is:
          // Change password
          aListener = new ActionListener() {
               public void actionPerformed(ActionEvent e) {
                    String id = ssnField.getText();
                   ChangeMyPassword cmp = new ChangeMyPassword(MainFrame.this, id);
                   boolean success = currentUser.persist();
                   cmp.dispose();          
          changePasswordButton.addActionListener(aListener);Now remember that I set the password that should be written in ChangeMyPassword class as you can see above. Now that I called the persist method, it should write all the details back to the text. For some reason it not doing that and I don�t understand why.
The persist method:
     public boolean persist() {
          FileOutputStream fos = null;
          PrintWriter pw = null;
          try {
               // Attempt to create the ssn.dat file.  Note that
               // it will overwrite one if it already exists.
               fos = new FileOutputStream("C://Files//" + getSsn() + ".dat");
               pw = new PrintWriter(fos);
               // First, we output the header record as a tab-delimited
               // record.
               pw.println(getSsn() + "\t" + getName() + "\t" +
                       getMajor() + "\t" + getDegree() + "\t" + getPassword());
               // Then, we output one record for every Section that
               // the Student is enrolled in.
               for (int i = 0; i < attends.size(); i++) {
                    Section s = (Section) attends.elementAt(i);
                    pw.println(s.getFullSectionNo());
               pw.close();
               fos.close(); //? needed?
          catch (IOException e) {
               // Signal that an error has occurred.
               return false;
          // All is well!
          return true;
     }