CMPS 134 Fall 2019 Programming Assignment #4

CMPS 134 Fall 2019
Programming Assignment #4: Calendar Date Conversions
Due: 11:59pm, Sunday, October 13

Background

Format Example 1 Example 2

mm/dd/yyyy 10/8/2019 05/23/1966

yyyy-mm-dd 2019-10-08 1966-5-23

dd-mm-yyyy 08-10-2019 23-5-1966

dd-Mon-yyyy 8-Oct-2019 23-May-1966

Month day, year October 08, 2019 May 23, 1966

day Month year 8 October 2019 23 May 1966

Calendar dates are expressed using several different formats. Here, we consider the 8-digit, or yyyymmdd, format to be "canonical". Examples are 20191008 (year: 2019, month: 10, day: 8) and 19850323. We will be concerned with six other calendar date formats, as illustrated to the right. Except in the canonical form (which always has eight digits), padding month and day numbers less than ten with a leading zero is optional, as suggested by the examples.

Format	Example 1	Example 2
mm/dd/yyyy	10/8/2019	05/23/1966
yyyy-mm-dd	2019-10-08	1966-5-23
dd-mm-yyyy	08-10-2019	23-5-1966
dd-Mon-yyyy	8-Oct-2019	23-May-1966
Month day, year	October 08, 2019	May 23, 1966
day Month year	8 October 2019	23 May 1966

Specification

You are given three Java classes, the second of which you are to complete.

Pad: Utility class containing (static) methods that pad strings to desired lengths. Each of the classes listed below uses one of Pad's methods.

DateConverters: Java class that has six public methods, each of which has as its purpose to translate a calendar date in one of the formats shown in the nearby table into the corresponding canonical-form calendar date. The method that translates mm/dd/yyyy dates is given in full; consider it to be a model for you to emulate when completing the remaining five. Of course, you are free to introduce new class constants and new private utility methods.

DateConversionDriver: Java application to use for testing purposes. It repeatedly prompts the user to enter a calendar date and, upon reading it, passes it to each of the six public methods in the DateConverters class, reporting each one's result. Of course, because any string entered by the user will conform to at most one of the six date formats, you should expect at most one of the six methods to produce a meaningful answer. Indeed, most of them may cause an exception to be thrown when given a date of the "wrong" format. The driver is designed to handle that without aborting; it simply reports that an exception was thrown.

Sample Dialog

Enter a calendar date:>8/14/1985 mm/dd/yyyy "19850814" dd-mm-yyyy Exception!!! yyyy-mm-dd Exception!!! dd-Mon-yyyy Exception!!! Month day, year Exception!!! day Month year Exception!!! Enter a calendar date:>09-13-2010 mm/dd/yyyy Exception!!! dd-mm-yyyy "20101309" yyyy-mm-dd "0009132010" dd-Mon-yyyy "20100009" Month day, year Exception!!! day Month year Exception!!! Enter a calendar date:>14 November 1994 mm/dd/yyyy Exception!!! dd-mm-yyyy Exception!!! yyyy-mm-dd Exception!!! dd-Mon-yyyy Exception!!! Month day, year Exception!!! day Month year "19941114" Enter a calendar date:> Done!

To the right is a sample user/program dialog produced by running the driver program (making use of a DateConverters class in which all six conversion methods are complete and correct). User input is in boldface. You'll notice that, more often than not, when a conversion method is applied to a date not in the format it expects, it ends up throwing an exception.

You might also notice that, even though the second date entered by the user is a syntactically valid dd-mm-yyyy date, it is semantically invalid, as there is no such thing as the 13th month. The method for converting dd-mm-yyyy dates is not responsible for recognizing semantic invalidity, nor is any other of the conversion methods. Determining semantic validity is outside the scope of this assignment.

Additional/Optional (Extra Credit)

Two of the six non-canonical calendar date forms include spaces. To impress your instructor, make the methods that convert those forms able to handle dates in which leading, trailing, and "extra" internal spaces occur. For example, " October 12 , 1988 "

Submitting Your Source Code

To submit your program, log into the Student File Submission System (see link near top of course web page) and then click on the link to the "prog4_dir" folder. In the text box, enter a title (e.g., "date conversion"), then click on one of the "Browse" buttons, after which you can browse within your computer's secondary storage to find the file that you want to submit/upload, which is the file containing your DateConverters Java source code. Its name must be DateConverters.java. (Do not submit the associated .class file.)

After you click on the "SUBMIT FORM" button, you should get a message confirming that your file was submitted/uploaded. You can then click on the large "Continue" link at the top right of the page, which should take you back to the page from which you made the submission. Above the "Form to Submit Message ..." there should be a table that lists any files that you have submitted to the prog4_dir folder. To double-check that you submitted the intended file, click on the corresponding link to download the file into some application (e.g., jGrasp, WordPad) that allows you to examine it to verify that it is the correct file.

Note that you can submit more than one time to the same folder. Hence, if, after submitting, you improve your program (e.g., by fixing logic errors or by enhancing your comments), you should submit the newer version. Do not use a new file name every time you submit. Rather, use the same name each time. Within your submission folder, any previously submitted file having the same name will be renamed automatically (and still be accessible to both you and your instructor). Generally speaking, however, your instructor will probably examine only your most recent submission, unless you make a request to the contrary.

Make sure to include comments in your program identifying yourself, indicating that it is a solution to CMPS 134's Prog. Assg. #4, acknowledging any persons who aided you in developing your solution, and pointing out any defects of which you are aware.