Exception Handling and Files - Learning Java Through Games - page 306

if ( f i leChooser . showDialog (NotepadFrame . this , "Save" )==
JFileChooser .APPROVEOPTION) {
File newFile = fileChooser . getSelectedFile() ;
try (PrintWriter fileWritter = new PrintWriter(newFile)) {
fileWritter .print(textArea.getText());

} catch (Exception exception) {

}

}

}

} );

}

}

13.3 Data Files
We will next give an example of how to read and write binary data to and from a file.
We will create a simple bank application. The application will be by no means complete.
Rather, it will be a toy example that shows how objects can be read and written to a file.
The main BankApp class is shown next. It creates two customers and an employee and tests
how deposits and withdraws can be made and how binary data can be written to and from
afile.Notethatthe main method throws an exception. This is the reason we do not need
a try-catch block inside the method.
import java . io .

;
import java . util .

∗

;

∗

public class BankApp {
public static void main(String [] args) throws Exception {

ArrayList < Person > people = new ArrayList <> () ;
Customer bob = new Customer( "Bob" , new Person .Address(123 , "Main" ,
"Chicago" , "IL" , 60641) , 5555555555L) ;
Customer ann = new Customer( "Ann" , new Person .Address(444 , "King" ,
"New York" , "NY" , 10466) , 666666666L) ;
Employee suzan = new Employee( "Susan" , new Person .Address(444 , "
King" , "New York" , "NY" , 10466) , 777777777L, 80000) ;
people .add(bob) ;
people . add(ann) ;
people .add(suzan) ;
BankAccount account1 = new BankAccount(1000, bob) ;
bob . addBankAccount( account1 ) ;
account1 . deposit(100000, suzan) ;
BankAccount account2 = new BankAccount(50000, ann) ;
ann . addBankAccount( account2 ) ;
account2 .withdraw(200 , suzan) ;

FileOutputStream fileOut = new FileOutputStream( "bank.ser" );
ObjectOutputStream out = new ObjectOutputStream( fileOut ) ;
out .writeObject(people) ;
out . close () ;
fileOut . close () ;
people = null ;