Update the Customer, BankAccount and SavingsAccount classes such that they can be constructed from information stored in a file and that they can be saved to a text file. The following describe how the tests expect this information be saved to a file and read from a file.
Customer
Add a constructor that takes a BufferedReader (import from java.io) as an argument. This constructor should be declared to throw IOException (also imported from java.io). Read two lines from this BufferedReader.
o If there are no lines in the file, use defaults for the instance variables.
o The first line should contain the customer’s name. If this line contains the text null, throw an IOException with the message ‘Customer is null in file’.
o If there is a first line but no second line, throw an IOException with the message ‘No customer ID found in file’.
Add a method called save that takes a PrintWriter as an argument (import from java.io). The method should be declared to throw IOException. Write the name and id to the PrintWriter, each on their own line.
BankAccount
Add a constructor that takes a BufferedReader (import from java.io) as an argument. This constructor should be declared to throw IOException (also imported from java.io). The first line from the reader should be the balance, the second line the accountNumber. Once those have been read, create the accountHolder by invoking the Customer constructor that takes a BufferedReader. If this Customer constructor throws an IOException, set the accountHolder to null.
Add a method called saveToTextFile that takes a filename (as a string) as an argument and is declared to throw an IOException. It should create a PrintWriter object using the filename provided as an argument. Then write the balance and account number, each on their own line, to the file.
If the accountHolder is null, write the string null to the file. Otherwise, invoke ‘save’ on the accountHolder and pass the PrintWriter object to it as an argument.
Before returning from the saveToTextFile method, make sure to close the PrintWriter object.
SavingsAccount
Add a constructor that takes a BufferedReader as an argument. This constructor should be declared to throw IOException. It should invoke the parent constructor that takes a BufferedReader as well.
The first line that this constructor will read will contain the annual Interest rate. The next line will contain the minimum balance.
Add a method called saveToTextFile that takes a filename as a string as an argument and is declared to throw an IOException.
It should first invoke the saveToTextFile method in the parent, passing it the same filename.
Then create a PrintWriter object that opened for appending. Write, to the end of the file, the annualInterestRate and the minimumBalance, each on their own line.
Before returning from the saveToTextFile method, make sure to close the PrintWriter object.
