DemoTestingForExceptions

This class is a very simple demonstration of how to catch exceptions and how exception handling allows a program to keep running even when a problem occurs.

public class DemoTestingForExceptions
{
    private static ConsoleColor _Normal = Console.ForegroundColor;

    public static void Start()
    {
        string[] actualAuthors = { "Dan Gilleland", "B. N. D'erdundat", "Dr. Ink" };
        string actualTitle = "Java: Bean There, Done That";
        string actualBarCode = "0-12345678-9";

        // Demo a normal creation of a Book object
        Console.WriteLine("Testing valid data");
        TestBook(actualTitle, actualAuthors, actualBarCode);

        // Demo testing the Book class for various combinations of data
        Console.WriteLine("Testing empty title");
        TestBook("", actualAuthors, actualBarCode);
        Console.WriteLine("Testing null title");
        TestBook(null, actualAuthors, actualBarCode);
        Console.WriteLine("Testing empty author list");
        TestBook(actualTitle, new String[0], actualBarCode);
        Console.WriteLine("Testing null author list");
        TestBook(actualTitle, null, actualBarCode);
        Console.WriteLine("Testing empty bar code");
        TestBook(actualTitle, actualAuthors, "");
        Console.WriteLine("Testing null bar code");
        TestBook(actualTitle, actualAuthors, null);
        Console.WriteLine("Testing all nulls");
        TestBook(null, null, null);
    }

    private static void TestBook(string title, string[] authors, string barCode)
    {
        try
        {
            Book theBook = new Book(title, authors, new ISBN(barCode));
            Console.WriteLine("I creatd the following book:");
            Console.WriteLine("    Title: " + theBook.Title);
            Console.Write("    Authors: ");
            foreach (string author in theBook.Authors)
                Console.Write(author + ", ");
            Console.WriteLine("(" + theBook.Authors.Length + " authors)");
            Console.WriteLine("    ISBN: " + theBook.Isbn.BarCode);
            Console.WriteLine("-----------------------------------------");
            Console.WriteLine();
        }
        catch (Exception ex)
        {
            Console.ForegroundColor = ConsoleColor.Red;
            Console.WriteLine("!-- " + ex.Message + " --!");
            Console.ForegroundColor = _Normal;
        }
    }
}