I\'m a newbie in java. I\'m writing a class where the constructor must check the price parameter and ensure it is not a negative number. And if it is negative, it must set
Not a cure for the recursion problem, but you should also consider checking the price at construction time.
Sometimes (most times?) it is better that your constructor fails with an Exception instead of allowing the construction of an inconsistent object. This way it is easier to localize such an Error.
Example:
public Book(String bookTitle, String bookAuthor, String bookCode, int bookPages, boolean paperback, double bookRetail)
{
if (bookRetail < 0.0)
throw new IllegalArgumentException("negative bookRetail: " + bookRetail);
...
}
The risk is that your application can fail when in the production environment, which can be a mess. To avoid this, you can use an assert
or, at least, give out or log the error and use some alternative. The assert
check must be turned on for development and may be turned off at production. For Detail see Programming With Assertions
public Book(String bookTitle, String bookAuthor, String bookCode, int bookPages, boolean paperback, double bookRetail)
{
assert bookRetail >= 0.0 : bookRetail;
...
}
or
public Book(String bookTitle, String bookAuthor, String bookCode, int bookPages, boolean paperback, double bookRetail)
{
if (bookRetail >= 0.0) {
price = bookRetail;
} else {
price = 0.0;
// display or log the "illegal argument"
Exception ex = new IllegalArgumentException("negative bookRetail: " + bookRetail);
ex.printStackTrace();
}
...
}