HW$8$ File Operations

Using the StockItemManager files in the File IO module, as a model, create a set of programs that:

Instantiates and writes five Book objects to a file. $($Hardcode the creation of Book objects with their attribute values.$)$

Reads the original data from the file and displays it

Updates the title for one Book

Updates the price for another Book

Reads the modified data from the updated file and displays it$.$ Your Book class must have the following attributes:

ISBN

title

yearPublished

price

It must also have $$set$$ and $$get$$ methods for these attributes, plus a toString method.

The most difficult part of using Random Access Files is handling Strings. The variable lengths of Strings cause problems. Random Access Files require that every record have the same length. This enables a program to move the file pointer to a particular location. When a program wants to move the pointer to record five, let$$s say, it has to know how many bytes record five is from the beginning of the file. If all the records have different lengths, this would not be possible, and the program would put the file pointer in the wrong place.

To relate this problem to this project: if one book has the title $$Java$$ and another has the title $$Introduction to Java$,$ the first title has $16$ bytes $($Java Strings use Unicode two$-$byte characters$)$ and the second has $38$ bytes. We need to make Strings occupy the same amount of space in a file, so we must decide on a standard length for String fields like title. Let$$s say we determine that titles should have $48$ bytes. Then we would right pad the values of titles that have fewer than $48$ bytes and truncate those that have more. The sample program demonstrates this with its setCorrectLength method.