import java.io.*;
public class Book{
private String code;
private String title;
private double price;
public Book(String bookCode, String bookTitle, double bookPrice){
code = bookCode;
title = bookTitle;
price = bookPrice;
}
public Book(String bookCode) throws IOException{
code = bookCode;
Book tempBook = BookIO.readRecord(bookCode);
title = tempBook.getTitle();
price = tempBook.getPrice();
}
public String getCode(){ return code; }
public String getTitle(){ return title; }
public double getPrice(){ return price; }
}

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import java.text.*;
import java.io.*;
public class BookFrame extends JFrame{
public BookFrame(){
setTitle("Book Maintenance");
Toolkit tk = Toolkit.getDefaultToolkit();
Dimension d = tk.getScreenSize();
int width = 400, height = 200;
setBounds((d.width - width)/2, (d.height - height)/2, width, height);
setResizable(false);
addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
BookIO.close();
System.exit(0);
}
});
Container contentPane = getContentPane();
BookPanel panel = new BookPanel();
contentPane.add(panel);
}
public static void main(String[] args){
JFrame frame = new BookFrame();
frame.show();
}
}
class BookPanel extends JPanel implements ActionListener,
DocumentListener, KeyListener{
private JButton addButton, updateButton, deleteButton, exitButton,
firstButton, prevButton, nextButton, lastButton;
private JLabel codeLabel, titleLabel, priceLabel;
private JTextField codeField, titleField, priceField;
private boolean addFlag = false;
private NumberFormat currency = NumberFormat.getCurrencyInstance();
private Book currentBook = null;
public BookPanel(){
codeLabel = new JLabel("Code: ");
codeField = new JTextField("", 7);
titleLabel = new JLabel("Title: ");
titleField = new JTextField("", 26);
priceLabel = new JLabel("Price: ");
priceField = new JTextField("", 7);
JPanel updatePanel = new JPanel();
addButton = new JButton("Add");
updateButton = new JButton("Update");
deleteButton = new JButton("Delete");
exitButton = new JButton("Exit");
updatePanel.add(addButton);
updatePanel.add(updateButton);
updatePanel.add(deleteButton);
updatePanel.add(exitButton);
JPanel navigationPanel = new JPanel();
firstButton = new JButton("First");
prevButton = new JButton("Prev");
nextButton = new JButton("Next");
lastButton = new JButton("Last");
navigationPanel.add(firstButton);
navigationPanel.add(prevButton);
navigationPanel.add(nextButton);
navigationPanel.add(lastButton);
addButton.addActionListener(this);
updateButton.addActionListener(this);
deleteButton.addActionListener(this);
exitButton.addActionListener(this);
firstButton.addActionListener(this);
prevButton.addActionListener(this);
nextButton.addActionListener(this);
lastButton.addActionListener(this);
codeField.addKeyListener(this);
titleField.addKeyListener(this);
priceField.addKeyListener(this);
titleField.getDocument().addDocumentListener(thi s);
priceField.getDocument().addDocumentListener(thi s);
setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
c.weightx = 100;
c.weighty = 100;
c.ipadx = 5;
c.anchor = GridBagConstraints.EAST;
c = getConstraints(c, 1, 1, 1, 1);
add(codeLabel, c);
c = getConstraints(c, 1, 2, 1, 1);
add(titleLabel, c);
c = getConstraints(c, 1, 3, 1, 1);
add(priceLabel, c);
c.anchor = GridBagConstraints.WEST;
c = getConstraints(c, 2, 1, 3, 1);
add(codeField, c);
c = getConstraints(c, 2, 2, 3, 1);
add(titleField, c);
c = getConstraints(c, 2, 3, 3, 1);
add(priceField, c);
c.anchor = GridBagConstraints.CENTER;
c = getConstraints(c, 1, 4, 4, 1);
add(updatePanel, c);
c = getConstraints(c, 1, 5, 4, 1);
add(navigationPanel, c);
try{
BookIO.open();
currentBook = BookIO.moveFirst();
}
catch (FileNotFoundException e){
JOptionPane.showMessageDialog(null, "FileNotFoundException");
System.exit(1);
}
catch (IOException e){
JOptionPane.showMessageDialog(null, "IOException");
}
performBookDisplay();
enableButtons(true);
}
private GridBagConstraints getConstraints(GridBagConstraints c,
int x, int y, int width, int height){
c.gridx = x;
c.gridy = y;
c.gridwidth = width;
c.gridheight = height;
return c;
}
private void performBookDisplay(){
codeField.setText(currentBook.getCode());
titleField.setText(currentBook.getTitle());
priceField.setText(currency.format(currentBook.g etPrice()));
}
private void enableButtons(boolean flag1){
boolean flag2 = false;
if (flag1 == false) flag2 = true;
updateButton.setEnabled(flag2);
addButton.setEnabled(flag1);
deleteButton.setEnabled(flag1);
firstButton.setEnabled(flag1);
nextButton.setEnabled(flag1);
prevButton.setEnabled(flag1);
lastButton.setEnabled(flag1);
}
public void actionPerformed(ActionEvent e){
try{
Object source = e.getSource();
if (source == exitButton){
BookIO.close();
System.exit(0);
}
else if (source == firstButton){
currentBook = BookIO.moveFirst();
performBookDisplay();
enableButtons(true);
}
else if (source == prevButton){
currentBook = BookIO.movePrevious();
performBookDisplay();
enableButtons(true);
}
else if (source == nextButton){
currentBook = BookIO.moveNext();
performBookDisplay();
enableButtons(true);
}
else if (source == lastButton){
currentBook = BookIO.moveLast();
performBookDisplay();
enableButtons(true);
}
else if (source == addButton){
codeField.requestFocus();
enableButtons(false);
codeField.setText("");
titleField.setText("");
priceField.setText("");
addFlag = true;
}
else if (source == updateButton){
String priceString = priceField.getText();
if (priceString.charAt(0) == '$')
priceString = priceString.substring(1);
double price = Double.parseDouble(priceString);
Book book = new Book(codeField.getText(),
titleField.getText(), price);
if (addFlag == false){
BookIO.updateRecord(book);
}
if (addFlag == true){
BookIO.addRecord(book);
addFlag = false;
}
currentBook = book;
performBookDisplay();
enableButtons(true);
}
else if(source == deleteButton){
BookIO.deleteRecord(currentBook.getCode( ));
nextButton.requestFocus();
nextButton.doClick();
}
}
catch (FileNotFoundException fnfe){
JOptionPane.showMessageDialog(this, "FileNotFoundException");
}
catch (NumberFormatException nfe){
JOptionPane.showMessageDialog(this, "NumberFormatException");
}
catch (IOException ioe){
JOptionPane.showMessageDialog(this, "IOException");
}
}
public void keyPressed(KeyEvent e){
int keyCode = e.getKeyCode();
if (keyCode == KeyEvent.VK_ESCAPE){
codeField.requestFocus();
performBookDisplay();
enableButtons(true);
}
}
public void keyReleased(KeyEvent e){}
public void keyTyped(KeyEvent e){}
public void insertUpdate(DocumentEvent e){
enableButtons(false);
}
public void removeUpdate(DocumentEvent e){
enableButtons(false);
}
public void changedUpdate(DocumentEvent e){}
}

import java.io.*;
import java.util.*;
public class BookIO{
private static Book book = null;
private static String[] codes = null;
private static RandomAccessFile randomFile = null;
private static final File BOOK_FILE = new File("books.dat");
private static final int CODE_SIZE = 4;
private static final int TITLE_SIZE = 20;
private static final int RECORD_SIZE = CODE_SIZE*2 + TITLE_SIZE*2 + 8;
public static void open() throws IOException{
randomFile = new RandomAccessFile(BOOK_FILE, "rw");
codes = readCodes();
}
public static void close(){
try{
randomFile.close();
}
catch(IOException e){
System.out.println("I/OException thrown when closing file.");
}
}
public static int getRecordCount() throws IOException{
long length = BOOK_FILE.length();
int recordCount = (int) (length / RECORD_SIZE);
return recordCount;
}
public static String readString(DataInput in, int length)
throws IOException{
String s = "";
int i = 0;
while (i < length){
char c = in.readChar();
if (c!=0)
s += c;
i++;
}
return s;
}
public static Book readRecord(int recordNumber) throws IOException{
randomFile.seek((recordNumber-1) * RECORD_SIZE);
String code = readString(randomFile, CODE_SIZE);
String title = readString(randomFile, TITLE_SIZE);
double price = randomFile.readDouble();
book = new Book(code, title, price);
return book;
}
public static Book readRecord(String bookCode) throws IOException{
int recordNumber = getRecordNumber(bookCode);
book = readRecord(recordNumber);
return book;
}
public static int getRecordNumber(String bookCode) throws IOException{
int match = -1;
int i = 0;
boolean flag = true;
while ((i < getRecordCount()) && (flag==true)){
if (bookCode.equals(codes[i])){
match = i+1;
flag = false;
}
i++;
}
return match;
}
public static String[] readCodes() throws IOException{
codes = new String[getRecordCount()];
for (int i = 0; i < getRecordCount(); i++){
randomFile.seek(i * RECORD_SIZE);
codes[i] = readString(randomFile, CODE_SIZE);
}
return codes;
}
public static String[] readTitles() throws IOException{
String[] titles = new String[getRecordCount()];
for (int i = 0; i < getRecordCount(); i++){
randomFile.seek(i * RECORD_SIZE + 8);
titles[i] = readString(randomFile, TITLE_SIZE);
}
return titles;
}
public static void writeString(DataOutput out, String s, int length)
throws IOException{
for (int i = 0; i < length; i++){
if (i < s.length())
out.writeChar(s.charAt(i));
else
out.writeChar(0);
}
}
public static void writeRecord(Book book, int recordNumber)
throws IOException{
randomFile.seek((recordNumber-1) * RECORD_SIZE);
writeString(randomFile, book.getCode(), CODE_SIZE);
writeString(randomFile, book.getTitle(), TITLE_SIZE);
randomFile.writeDouble(book.getPrice());
}
public static Book moveFirst() throws IOException{
book = readRecord(1);
return book;
}
public static Book movePrevious() throws IOException{
int recordNumber = getRecordNumber(book.getCode());
if (recordNumber != 1)
book = readRecord(recordNumber - 1);
return book;
}
public static Book moveNext() throws IOException{
int recordNumber = getRecordNumber(book.getCode());
if (recordNumber != getRecordCount())
book = readRecord(recordNumber + 1);
return book;
}
public static Book moveLast() throws IOException{
int lastRecordNumber = getRecordCount();
book = readRecord(lastRecordNumber);
return book;
}
public static void addRecord(Book addBook) throws IOException{
writeRecord(addBook, getRecordCount() + 1);
close();
open();
}
public static void updateRecord(Book book) throws IOException{
int recordNumber = getRecordNumber(book.getCode());
writeRecord(book, recordNumber);
}
public static void deleteRecord(String bookCode) throws IOException{
int recordNumber = getRecordNumber(bookCode);
Vector books = new Vector();
for (int i = 0; i< getRecordCount(); i++){
books.add(readRecord(i+1));
}
books.remove(recordNumber-1);
randomFile.setLength(RECORD_SIZE *(getRecordCount() -1));
for (int i = 0; i