pbo

1. /**
* The Item class represents a multi-media item.
* Information about the item is stored and can be retrieved.
* This class serves as a superclass for more specific itms.
*
* @author Michael Kolling and David J. Barnes
* @version 2008.03.30
*/
public class Item
{
private String title;
private int playingTime;
private boolean gotIt;
private String comment;
/**
* Initialise the fields of the item.
* @param theTitle The title of this item.
* @param time The running time of this item.
*/
public Item(String theTitle, int time)
{
title = theTitle;
playingTime = time;
gotIt = false;
comment = "<no comment>";
}
/**
* Enter a comment for this item.
* @param comment The comment to be entered.
*/
public void setComment(String comment)
{
this.comment = comment;
}
/**
* @return The comment for this item.
*/
public String getComment()
{
return comment;
}
/**
* Set the flag indicating whether we own this item.
* @param ownIt true if we own the item, false otherwise.
*/
public void setOwn(boolean ownIt)
{
gotIt = ownIt;

2. }
/**
* @return Information whether we own a copy of this item.
*/
public boolean getOwn()
{
return gotIt;
}
/**
* Print details of this item to the text terminal.
*/
public void print()
{
System.out.print(title + " (" + playingTime + " mins)");
if(gotIt) {
System.out.println("*");
} else {
System.out.println();
}
System.out.println(" " + comment);
}
}

3. /**
* The CD class represents a CD object. Information about the
* CD is stored and can be retrieved.
*
* @author Michael Kolling and David J. Barnes
* @version 2008.03.30
*/
public class CD extends Item
{
private String artist;
private int numberOfTracks;
/**
* Initialize the CD.
* @param theTitle The title of the CD.
* @param theArtist The artist of the CD.
* @param tracks The number of tracks on the CD.
* @param time The playing time of the CD.
*/
public CD(String theTitle, String theArtist, int tracks, int time)
{
super(theTitle, time);
artist = theArtist;
numberOfTracks = tracks;
}
/**
* @return The artist for this CD.
*/
public String getArtist()
{
return artist;
}
/**
* @return The number of tracks on this CD.
*/
public int getNumberOfTracks()
{
return numberOfTracks;
}
/**
* Print details of this CD to the text terminal.
*/
public void print()
{
System.out.println(" " + artist);
System.out.println(" tracks: " + numberOfTracks);
}
}

4. /**
* The DVD class represents a DVD object. Information about the
* DVD is stored and can be retrieved. We assume that we only deal
* with movie DVDs at this stage.
*
* @author Michael Kolling and David J. Barnes
* @version 2008.03.30
*/
public class DVD extends Item
{
private String director;
/**
* Constructor for objects of class DVD
* @param theTitle The title of this DVD.
* @param theDirector The director of this DVD.
* @param time The running time of the main feature.
*/
public DVD(String theTitle, String theDirector, int time)
{
super(theTitle, time);
director = theDirector;
}
/**
* @return The director for this DVD.
*/
public String getDirector()
{
return director;
}
/**
* Print details of this DVD to the text terminal.
*/
public void print()
{
System.out.println(" director: " + director);
}
}

5. import java.util.ArrayList;
/**
* The database class provides a facility to store CD and video
* objects. A list of all CDs and videos can be printed to the
* terminal.
*
* This version does not save the data to disk, and it does not
* provide any search functions.
*
* @author Michael Kolling and David J. Barnes
* @version 2008.03.30
*/
public class Database
{
private ArrayList<Item> items;
/**
* Construct an empty Database.
*/
public Database()
{
items = new ArrayList<Item>();
}
/**
* Add an item to the database.
* @param theItem The item to be added.
*/
public void addItem(Item theItem)
{
items.add(theItem);
}
/**
* Print a list of all currently stored CDs and videos to the
* text terminal.
*/
public void list()
{
for(Item item : items)
{
item.print();
}
}
}