School of Engineering and Applied Science Department of Computer Science CSci 53 -- Introduction to Software Development http://www.seas.gwu.edu/~csci53/fall04 Prof. Michael B. Feldman mfeldman@gwu.edu

Project:

For example, if the user enters a starting date of May 10, 1999 and an ending date of September 15, 2002, the file will contain a line for each day from May 10 through December of 1999, all of 2000, all of 2001, and all dates in 2002 through September 15. Remember, when turning in your results,be sure to include these output files in their complete and unedited form. This may mean that there will be several pages to turn in.

Your dates should be output in the following format: May 3, 2002. When your program completes its run, test.datwill be an ordinary text file in your directory, which you can read with vi, type out (cat) to the screen, print, download, or whatever.

In this project you are NOT required to validate the dates or to test with invalid ones; you can assume the user will always enter valid data. However, your test plan must include several date ranges that will test whether your program "rolls over" properly from month to month and year to year. In Project 6 we'll combine this project with the Project 4 validation ideas.

Notes about Files

    1. //**************************************************************
   2. //  TestData.java       Author: Lewis/Loftus
   3. //
   4. //  Demonstrates the use of a character file output stream.
   5. //*************************************************************
   6.
   7. import java.util.Random;
   8. import java.io.*;
   9.
  10. public class TestData
  11. {
  12.    //------------------------------------------------------------
  13.    //  Creates a file of test data that consists of ten lines each
  14.    //  containing ten integer values in the range 10 to 99.
  15.    //------------------------------------------------------------
  16.    public static void main (String[] args) throws IOException
  17.    {
  18.       final int MAX = 10;
  19.
  20.       int value;
  21.       String file = "test.dat";
  22.
  23.       Random rand = new Random();
  24.
  25.       FileWriter fw = new FileWriter (file);
  26.       BufferedWriter bw = new BufferedWriter (fw);
  27.       PrintWriter outFile = new PrintWriter (bw);
  28.
  29.       for (int line=1; line <= MAX; line++)
  30.       {
  31.          for (int num=1; num <= MAX; num++)
  32.          {
  33.             value = rand.nextInt (90) + 10;
  34.             outFile.print (value + "   ");
  35.          }
  36.          outFile.println ();
  37.       }
  38.
  39.       outFile.close();
  40.       System.out.println ("Output file has been created: " + file);
  41.    }
  42. }

Here are the key things to notice and incorporate in your program:

1. a new import statement (line 8) (your project needs java.io but doesn't need Random);
2. the phrase throws IOException in line 16;
3. lines 21, 25, 26, and 27, which set up the file;
4. lines 34 and 36, which show how to write to this file;
5. line 39, which closes the file and is important to do just before your program ends.

What to submit

Your grade will be calculated on a 20-point basis, as follows:

• 6 points -- analysis and design (including algorithm in structured English)
• 4 points -- test plan
• 6 points -- correct execution of program according to test plan
• 4 points -- layout and style of program source code

Extra credit:

MBF 10/11/04