CS 163/164, Fall 2016

Lab 13b - Music Library (Part 2)

Wed-Fri, Oct. 19-21, 2016

Objectives of this Lab

• Continue practicing file input/output,
• practice searching arrays of objects, and
• practice sorting arrays of objects.

Description

1. Implement a public static method writeLibrary in the Library class that takes a String parameter with the output filename, as follows:

       public static void writeLibrary(String outputFile);
       

2. Call writeLibrary from your main (after readLibrary) with args[1] as the parameter.
3. Do not hard-code the file name, use the name passed in as a parameter.
4. To implement writeLibrary, open a PrintWriter and copy the code from main that iterates the array of Music objects. You should get the same output as in the previous lab, except the method will send the output to a file.

   1: Brown Eyed Girl, Blowin' Your Mind!, Van Morrison, 1967
   2: Stop Putting the Hurt on Me, Lucille, B. B. King, 1968
   3: Another Brick in the Wall, The Wall, Pink Floyd, 1979
   4: Funeral for a Friend, Goodbye Yellow Brick Road, Elton John, 1973
   5: Beat It, Thriller, Michael Jackson, 1982
   6: Like a Virgin, Like a Virgin, Madonna, 1984
   7: So Far Away, Brothers in Arms, Dire Straits, 1985
   8: Try a Little Tenderness, Swamp Boogie Queen, Katie Webster, 1990
   9: Hey Jack Kerouac, MTV Unplugged, 10,000 Maniacs, 1993
   10: Mockingbird, Encore, Eminem, 2005
   11: Jackdaw, Draw the Line, David Gray, 2009
   12: Someone Like You, 21, Adele, 2011
   Number of Tracks: 12
   Total cost: $13.78
       

5. Your output file should match this exactly.
6. The format above has a number for each title, starting at 1 and ending at the last number. Each field is separated by a comma and space, but there is no trailing comma or space.
7. Make sure that your program correctly writes all of the data in the input file to the output file.
8. Add code to writeLibrary figure out how much it would cost to buy all the titles in the file by iterating the array of Music objects and calling getPrice for each element. You must accumulate the total cost in a variable. Write the message below to the output file using PrintWriter.printf() to ensure 2 digits after the decimal point in the total cost.

1. Implement a public static method searchTitles in the Library class that takes a String parameter and prints all the tracks that contain that String.

       public static void searchTitles(String search);
       

2. This method will print in the same format as before, but will only print the titles containing the search string. Do NOT print the number of tracks or total cost!

1. Implement a public static method sortTitles in the Library class that sorts the array of in the Library by title. You will do this by iterating the library for each uppercase letter, and printing only the titles that start with that letter. Note that the resulting output is sorted only by the first letter, and is not completely alphabetized.

       public static void sortTitles();
       

2. This method will print in the same format as before, but will only print all the titles in the sorted order. Do NOT print the number of tracks or total cost!

Testing

Submissions

• Right click the project and select Export.
• Select Java JAR file format.
• Click the "Export Java source file and resources" tab.
• Name the file Library.jar, which will be stored in the workspace.
• Submit the resulting Library.jar to the Checkin tab.
• See the image below that shows the Eclipse screen for exporting.

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