hii ^^
I have a problem which is I have to delete a book when( I enter it's name and then press the delete button) and that book has been saved as an object in an array of list, and then written to a (txt )file.. once I press the delete button and then open that Txt file (I still find that book ) but in fact it has been deleted ! I noticed that when I save a new book after that and then open the txt file ,what I found that this file has only the new book which I recently saved and the deleted book has gone !
so how can I solve the prob. >> that when I press the delete button ,that book should be deleted at that time from the file !so when I open the file that book should be deleted !
NOTE : the update button has the same problem :((
here is the code of the buttons !
thanks ^^
private void SaveBActionPerformed(java.awt.event.ActionEvent evt) {
book object ;
createFile ();
save ();
for (int i = 0;i<saveBook.size();i++){
object=(book)saveBook.get(i);
writer.format ("%s %s %d %s %.2f\r\n",object.getName(),object.getAuthor(),object.getSerialn(),object.getDate(),object.getPrice());
}
Tf1.setText("");
Tf2.setText("");
Tf3.setText("");
Tf4.setText("");
Tf5.setText("");
closeFile ();
}
private void DeleteBActionPerformed(java.awt.event.ActionEvent evt) {
book DeleteBook=new book();
readFile ();
String nameVariable = Tf1.getText();
// System.out.println (nameVariable);
for (int i = 0;i<saveBook.size();i++){
DeleteBook=(book)saveBook.get(i);
String nameVariable2= DeleteBook.getName();
if (nameVariable.compareTo(nameVariable2)==0){
saveBook.remove(i);
}
}
Tf1.setText("");
Tf2.setText("");
Tf3.setText("");
Tf4.setText("");
Tf5.setText("");
}
private void UpdateBActionPerformed(java.awt.event.ActionEvent evt) {
book UpdateBook=new book();
readFile ();
String nameVariable = Tf1.getText();
// System.out.println (nameVariable);
for (int i = 0;i<saveBook.size();i++){
UpdateBook=(book)saveBook.get(i);
String nameVariable2= UpdateBook.getName();
if (nameVariable.compareTo(nameVariable2)==0){
int variable =i;
String Bookname;
String AuthorBook;
int SerialNum;
String datePublish;
double PriceB;
//Declartion of variables
Bookname=Tf1.getText();
AuthorBook=Tf2.getText();
SerialNum=Integer.parseInt(Tf3.getText());
datePublish=Tf4.getText();
PriceB=Double.parseDouble(Tf5.getText());
UpdateBook.setName(Bookname);
UpdateBook.setAuthor(AuthorBook);
UpdateBook.setSerialn(SerialNum);
UpdateBook.setDate(datePublish);
UpdateBook.setPrice(PriceB);
saveBook.add(UpdateBook);
saveBook.remove(i);
//writer.format ("%s %s %d %s %.2f\r\n",UpdateBook.getName(),UpdateBook.getAuthor(),UpdateBook.getSerialn(),UpdateBook.getDate(),UpdateBook.getPrice());
}
}
// closeFileRead ();
// closeFile ();
}
private void SearchBActionPerformed(java.awt.event.ActionEvent evt) {
book pBook ;
readFile ();
String nameVariable = Tf1.getText();
// System.out.println (nameVariable);
for (int i = 0;i<saveBook.size();i++){
pBook=(book)saveBook.get(i);
String nameVariable2= pBook.getName();
// System.out.println (nameVariable2);
if (nameVariable.compareTo(nameVariable2)==0){
Tf1.setText(pBook.getName());
Tf2.setText(pBook.getAuthor());
String SNString = String.valueOf(pBook.getSerialn());
Tf3.setText(SNString);
Tf4.setText(pBook.getDate());
String priceString = String.valueOf(pBook.getPrice());
Tf5.setText(priceString);
}
}
closeFileRead ();
}
//function Create
public void createFile (){
try {
writer=new Formatter ("Book.txt");
}
catch (Exception ex){
System.err.println ("Error");
}
}
//Function SAve
public void save (){
book objB=new book ();
String Bookname;
String AuthorBook;
int SerialNum;
String datePublish;
double PriceB;
//Declartion of variables
Bookname=Tf1.getText();
AuthorBook=Tf2.getText();
SerialNum=Integer.parseInt(Tf3.getText());
datePublish=Tf4.getText();
PriceB=Double.parseDouble(Tf5.getText());
objB.setName(Bookname);
objB.setAuthor(AuthorBook);
objB.setSerialn(SerialNum);
objB.setDate(datePublish);
objB.setPrice(PriceB);
saveBook.add(objB);
}
public void readFile(){
try {
reader=new Scanner (new File("Book.txt"));
}
catch (Exception ex){
System.err.printf("Error");
}
}
public void closeFileRead (){
if (reader !=null) {
reader.close ();
}
}
public void closeFile (){
if (writer !=null ){
writer.close ();
}
}
the code of the book class which is in the same pachage :P
import java.util.Date;
public class book {
private String BookN;
private String Author;
private int SerialN;
private String date;
private double Price;
public book (){
this ("","",0,"",0.0);
}
public book (String BN,String A,int SN,String d,double P){
setName (BN);
setAuthor (A);
setSerialn(SN);
setDate(d);
setPrice(P);
}
public void setName (String n){
BookN=n;
}
public void setAuthor (String A){Author=A;}
public void setSerialn(int no){SerialN=no;}
public void setDate(String d){date=d;}
public void setPrice(double p){Price=p;}
public String getName (){
return BookN;
}
public String getAuthor (){return Author;}
public int getSerialn(){return SerialN;}
public String getDate(){return date;}
public Double getPrice(){return Price;}
}
--------------------------
the class of the framedesign !
public class Hw1 extends javax.swing.JFrame {
private ArrayList saveBook;
private Formatter writer;
private Formatter writer2;
private File f;
private Scanner reader;
public Hw1() {
initComponents();
saveBook=new ArrayList ();
}
