Writing to dat using GUI

Question

Can someone please help me with my code as i am stuck, I have succesfully displayed the question i want to screen using the button find. Then and only then will the bottom panel be shown with the question and relevant answers displayed in text boxes.
I need help in overwriting what the text box said to what the user then changes it to and writing it to the dat file. any help on this would be greatly appreciated as its part of an assignment i have to do for next week and this is only one part of it cheers. My code is as follows:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
public class UpdateQuestions extends JFrame implements ActionListener
     Container cPane;
     JPanel p1,p2;
     JButton btnFind,btnUpdate,btnClose;
     JTextField tfNumberSearch,tfQuestionNum,tfQuestion,tfAnswerA,tfAnswerB,tfAnswerC,tfCorrect;
     JLabel lblNumberSearch,lblQuestion,lblAnswerA,lblAnswerB,lblAnswerC,lblCorrect;
     RandomAccessFile rf;
     UpdateQuestions()
          cPane = getContentPane();
          cPane.setBackground(Color.RED);
          //Build Update Window
          setTitle("Update Quiz Questions");
          setSize(1024,768);
          setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
          //Absolute Layout Manager
          cPane.setLayout(null);
          //Size & Layout For Top Panel
          p1 = new JPanel();
          p1.setBackground(Color.WHITE);
          p1.setBounds(50,50,600,100);
          p1.setLayout(null);
          cPane.add(p1);
          //Top Panel
          lblNumberSearch = new JLabel("Enter Question No");
          lblNumberSearch.setFont(new Font("Serif",Font.BOLD,24));
          lblNumberSearch.setForeground(Color.BLACK);
          lblNumberSearch.setBounds(10,30,200,50);
          p1.add(lblNumberSearch);
          tfNumberSearch = new JTextField();
          tfNumberSearch.setFont(new Font("Serif",Font.BOLD,18));
          tfNumberSearch.setColumns(3);
          tfNumberSearch.setForeground(Color.BLACK);
          tfNumberSearch.setBounds(210,30,100,50);
          p1.add(tfNumberSearch);
          btnFind = new JButton("Find");
          btnFind.setFont(new Font("Serif",Font.BOLD,26));
          btnFind.addActionListener(this);
          btnFind.setBounds(400,10,100,80);
          p1.add(btnFind);
          p1.setVisible(true);
          //Size & Layout For Bottom Panel
          p2 = new JPanel();
          p2.setBounds(50,250,900,400);
          p2.setLayout(null);
          cPane.add(p2);
          // Question Label & Text Box
          lblQuestion = new JLabel("Question");
          lblQuestion.setFont(new Font("Serif",Font.BOLD,24));
          lblQuestion.setForeground(Color.BLACK);
          lblQuestion.setBounds(10,10,330,50);
          p2.add(lblQuestion);
          tfQuestion = new JTextField();
          tfQuestion.setFont(new Font("Serif",Font.BOLD,18));
          tfQuestion.setColumns(50);
          tfQuestion.setForeground(Color.BLACK);
          tfQuestion.setBounds(150,10,600,50);
          p2.add(tfQuestion);
          //Answer A Label & Text Box
          lblAnswerA = new JLabel("Answer A");
          lblAnswerA.setFont(new Font("Serif",Font.BOLD,24));
          lblAnswerA.setForeground(Color.BLACK);
          lblAnswerA.setBounds(10,90,330,50);
          p2.add(lblAnswerA);
          tfAnswerA = new JTextField();
          tfAnswerA.setFont(new Font("Serif",Font.BOLD,18));
          tfAnswerA.setColumns(20);
          tfAnswerA.setForeground(Color.BLACK);
          tfAnswerA.setBounds(150,90,400,50);
          p2.add(tfAnswerA);
          //Answer B Label & Text Box
          lblAnswerB = new JLabel("Answer B");
          lblAnswerB.setFont(new Font("Serif",Font.BOLD,24));
          lblAnswerB.setForeground(Color.BLACK);
          lblAnswerB.setBounds(10,170,330,50);
          p2.add(lblAnswerB);
          tfAnswerB = new JTextField();
          tfAnswerB.setFont(new Font("Serif",Font.BOLD,18));
          tfAnswerB.setColumns(20);
          tfAnswerB.setForeground(Color.BLACK);
          tfAnswerB.setBounds(150,170,400,50);
          p2.add(tfAnswerB);
          //Answer C Label & Text Box
          lblAnswerC = new JLabel("Answer C");
          lblAnswerC.setFont(new Font("Serif",Font.BOLD,24));
          lblAnswerC.setForeground(Color.BLACK);
          lblAnswerC.setBounds(10,250,330,50);
          p2.add(lblAnswerC);
          tfAnswerC = new JTextField();
          tfAnswerC.setFont(new Font("Serif",Font.BOLD,18));
          tfAnswerC.setColumns(20);
          tfAnswerC.setForeground(Color.BLACK);
          tfAnswerC.setBounds(150,250,400,50);
          p2.add(tfAnswerC);
          //Correct Answer Label & Text Box
          lblCorrect = new JLabel("Correct");
          lblCorrect.setFont(new Font("Serif",Font.BOLD,24));
          lblCorrect.setForeground(Color.BLACK);
          lblCorrect.setBounds(10,330,330,50);
          p2.add(lblCorrect);
          tfCorrect = new JTextField();
          tfCorrect.setFont(new Font("Serif",Font.BOLD,18));
          tfCorrect.setColumns(20);
          tfCorrect.setForeground(Color.BLACK);
          tfCorrect.setBounds(150,330,400,50);
          p2.add(tfCorrect);
          btnUpdate = new JButton("Update");
          btnUpdate.setFont(new Font("Serif",Font.BOLD,26));
          btnUpdate.addActionListener(this);
          btnUpdate.setBounds(700,300,150,80);
          p2.add(btnUpdate);
          p2.setVisible(false);
     private String pad(String s,int size)
          int x;
          for (x = s.length(); x < size; x++)
               s = s + " ";
          return s;
     public void actionPerformed(ActionEvent e)
          int num;
          if(e.getSource()==btnClose)
               try
                    rf.close();
                    setVisible(false);
               catch(IOException ex3)
               JOptionPane.showMessageDialog(null,"Cannot Close Question.dat");
          if(e.getSource()==btnFind)
               boolean eof,found;
               int qNo;
               long posQ, posAnsA, posAnsB, posAnsC, posCorrect;
               String question="", answerA="", answerB="", answerC="", answerCorrect="";
               num = Integer.parseInt(tfNumberSearch.getText());
               eof=false;
               found=false;
               try
                    rf = new RandomAccessFile("Question.dat","rw");
                    rf.seek(0);
               catch(FileNotFoundException ex1)
                    JOptionPane.showMessageDialog(null,"Cannot Open Question.dat");
               catch (IOException ex)
                    eof=true;
               while(!eof)
                    try
                         qNo = rf.readInt();
                         posQ = rf.getFilePointer(); question = rf.readUTF();
                         posAnsA = rf.getFilePointer(); answerA=rf.readUTF();
                         posAnsB = rf.getFilePointer(); answerB=rf.readUTF();
                         posAnsC = rf.getFilePointer(); answerC=rf.readUTF();
                         posCorrect = rf.getFilePointer(); answerCorrect=rf.readUTF();
                         if(num==qNo)
                              found=true;
                              eof=true;
                              tfQuestion.setText(question);
                              tfAnswerA.setText(answerA);
                              tfAnswerB.setText(answerB);
                              tfAnswerC.setText(answerC);
                              tfCorrect.setText(answerCorrect);
                              p2.setVisible(true);
                              rf.close();                                                  
                    catch (IOException ex)
                         eof=true;
               }// End of While not !eof     
          }// End of Find Button
          if(e.getSource()==btnUpdate)
               String question, answerA, answerB, answerC, answerCorrect;
               long posQ, posAnsA, posAnsB, posAnsC, posCorrect;
               question = tfQuestion.getText();
               question = pad(question,80);
               answerA = tfAnswerA.getText();
               answerA = pad(answerA,20);
               answerB = tfAnswerB.getText();
               answerB = pad(answerB,20);
               answerC = tfAnswerC.getText();
               answerC = pad(answerC,20);
               answerCorrect = tfCorrect.getText();
               answerCorrect = pad(answerCorrect,20);
               rf.seek(posQ);
               rf.writeUTF(question);
               rf.seek(posAnsA);
               rf.writeUTF(answerA);
               rf.seek(posAnsB);
               rf.writeUTF(answerB);
               rf.seek(posAnsC);
               rf.writeUTF(answerC);
               rf.seek(posCorrect);
               rf.writeUTF(answerCorrect);
     }//End of Action Performed
}//End of UpdateQuestions

Answer 1

Create your JFrames, then use
myFirstFrame.setVisible( true );
// time to launch second
mySecondFrame.setVisible( true );
// time to hide second
mySecondFrame.setVisible( false );The simplest file I/O will work for you. Use a FileOutputStream to write the file. I think three lines of code should do the trick. See the API docs for java.io.