Managing Data

1
Managing Data

• Databases
• Arrays, Lists, and File I/O

2
An Array-based database

• public static String Artist new String5
• public static String Song new String5
• public static int length 0
• public static void main(String args)
• length Artist.length
• Artist0 "System of a Down"
• Song0 "Hypnotize"
• Artist1 "Every Time I Die"
• Song1 "Kill the Music"
• // etc

3
Whats wrong with this

• Two arrays must be synchronized
• Filling the arrays with Artists and Songs is done
  IN THE CODE. Bad.
• One more thing.

4
Sorting

• public static void sortByArtist()
• for (int y 0 y
• for (int z 0 z
• if ( Artistz.compareTo(Artisty) 0 )
• swap( y,z)
• // end if
• // end for z
• // end for y
• // end sort by artist

5
Swap permanently moves items

• public static void swap( int a, int b)
  String temp temp Artista Artista
  Artistb Artistb temp temp Songa
  Songa Songb Songb temp

6
Step 1 get information from files

• Put all the database info into a file, rather
  than in your code.