import java.io.File; import java.util.ArrayList; import comp202.fall2007.a5.comparator.ComparatorFactory; import comp202.fall2007.a5.filter.FilterFactory; import comp202.fall2007.a5.filter.SongFilter; import comp202.fall2007.a5.filter.StringMatchType; import comp202.fall2007.a5.util.Song; /** * A MusicCollection object represents a collection of * Songs. It differs from a Playlist in two major * ways: *

it does not impose an order on the Songs it contains
it allows itself to be queried to retrieve information about the * Songs it contains, or to retrieve all Songs * that it contains and that also meet certain conditions.

* *

* Unlike a Playlist, a MusicCollection does not * support the inclusion of the same Song multiple times. The * primary key used to uniquely identify Songs in a * MusicCollection is the full (absolute) path of the file * associated with each Song. If an attempt is made to add a * Song to a MusicCollection, and the path of * this Song is the same as the path of a Song * already included in the MusicCollection, the * MusicCollection should not change as a result. *

* *

* Also, the MusicCollection class does NOT support the * addition of null elements to a MusicCollection * object. If an attempt is made to add a null element to a * MusicCollection, the latter should not change as a result. *

* *

* A MusicCollection MUST be able to store and manage an * arbitrary number of Songs, limited only by the memory * available to the Java Virtual Machine. In other words, the implementation of * the MusicCollection class MUST NOT not impose an * artificial limit to the number of Songs a * MusicCollection can store and manage. *

*/ public class MusicCollection { private ArrayList songs; private FilterFactory factory; // *** Constructors *** /** * Creates a new empty MusicCollection. */ public MusicCollection() { this.songs = new ArrayList(); this.factory = new FilterFactory(); } // *** PRIVATE HELPER METHODS *** private ArrayList extractAlbums(SongFilter filter) { ArrayList albumTitles; Playlist songSet; String title; String last; Song song; int numberSongs; songSet = this.getSongs(filter); songSet.sort(ComparatorFactory.ASCENDING_ALBUM_COMPARATOR); numberSongs = songSet.getSize(); albumTitles = new ArrayList(); last = null; for (int i = 0; i < numberSongs; i++) { song = songSet.get(i); title = song.getAlbum(); if ((last == null) || (!title.equalsIgnoreCase(last))) { albumTitles.add(title); last = title; } } return albumTitles; } // *** PUBLIC METHODS *** /** *

* Makes this MusicCollection empty, so that it contains no * Songs. *

*/ public void clear() { this.songs.clear(); } /** *

* Returns an ArrayList of Strings containing * the names of the all artists who have produced at least one of the * Songs currently stored in this * MusicCollection, as given by the values of the artist * attribute of the Songs stored in this * MusicCollection. *

* *

* The name of each artist is included ONLY once in the returned * ArrayList, regardless of how many Songs * stored in this MusicCollection this artist has produced. * Also, equality is determined by comparing the artist attributes of * Songs. Finally, equality is determined in a case-INsensitive * manner. *

* *

* For example, artist names "Joe Bleau" and * "JOE BLEAU" are considered to be the same for the purposes * of determining the uniqueness of an artist's name, and only one of them * should be included in the ArrayList of artist names * returned by this method. *

* *

* However, "Joe Bleau" and * "Joe Bleau and Jane Doe" are considered to be different * artists for the purpose of determining the uniqueness of an artist's * name, and both should be included in the ArrayList of * artist names returned by this method. *

* *

* The artist names MUST appear within the returned * ArrayList in case-INsensitive lexicographical * order. Subsequent changes to the returned ArrayList * MUST NOT affect the state of this MusicCollection. * Likewise, subsequent changes to the state of this * MusicCollection MUST NOT have any impact on the * returned ArrayList. *

* * @return An ArrayList of Strings containing * the names of all artists who have produced at least one song * currently stored in this MusicCollection. */ public ArrayList getAllArtists() { Playlist songSet; ArrayList allArtists; String artistName; String last; Song song; int numberSongs; songSet = new Playlist(); songSet.addAll(this.songs); songSet.sort(ComparatorFactory.ASCENDING_ARTIST_COMPARATOR); numberSongs = songSet.getSize(); allArtists = new ArrayList(); last = null; for (int i = 0; i < numberSongs; i++) { song = songSet.get(i); artistName = song.getArtist(); if ((last == null) || (!artistName.equalsIgnoreCase(last))) { allArtists.add(artistName); last = artistName; } } return allArtists; } /** *

* Returns an ArrayList of Strings containing * the titles of all albums represented by Songs in this * MusicCollection. In other words, for an album title t * to be included in the returned ArrayList, there must be * at least one Song in this MusicCollection * whose album attribute is equal to this album title t. *

* *

* The title of each album is included ONLY once in the returned * ArrayList, regardless of how many Songs * stored in this MusicCollection have a given album title as * their album title attribute. Also, equality is determined in a case-INsensitive * manner. For example, album names "Joe Bleau: Greatest Hits" * and "JOE BLEAU: GREATEST HITS" are considered to be the * same for the purposes of determining the uniqueness of an album's title, * and only one of them should be included in the ArrayList * returned by this method. *

* *

* The album titles MUST appear within the returned * ArrayList in case-INsensitive lexicographical * order. Subsequent changes to the returned ArrayList * MUST NOT affect the state of this MusicCollection. * Likewise, subsequent changes to the state of this * MusicCollection MUST NOT have any impact on the * returned ArrayList. *

* * @return An ArrayList of Strings containing * the titles of all albums which include at least one song * currently stored in this MusicCollection. */ public ArrayList getAllAlbums() { return extractAlbums(this.factory.createEverythingFilter()); } /** *

* Returns an ArrayList of Strings containing * the titles of all albums to which the specified artist has contributed at * least one of the Songs stored in this * MusicCollection, as given by the values of the artist and * album attributes of the Songs stored in this * MusicCollection. *

* *

* For example, if artist "Joe Bleau" has contributed 2 songs to the album * titled Tribute to Jane Doe (assuming that a least one of these * songs is stored as a Song object in this * MusicCollection) and 10 songs to the album Joe Bleau: * Greatest Hits (again assuming that at least one of these songs is * stored as a Song object in this * MusicCollection), then the returned * ArrayList should contain * "Tribute to Jane Doe" and * "Joe Bleau: Greatest Hits". *

* *

* The title of each album is included ONLY once in the returned * ArrayList, regardless of how many Songs * stored in this MusicCollection this album contains. Also, * equality is determined in a case-INsensitive manner. For * example, album names "Joe Bleau: Greatest Hits" and * "JOE BLEAU: GREATEST HITS" are considered to be the same * for the purposes of determining the uniqueness of an artist's name, and * only one of them should be included in the ArrayList * returned by this method. *

* *

* * @param artistName * The artist whose whose album titles should be returned. * @return An ArrayList of String containing * the titles of all albums to which the specified artist has * contributed at least one of the Songs currently * stored in this MusicCollection. */ public ArrayList getContributedAlbums(String artistName) { return extractAlbums(this.factory.createArtistFilter(artistName, StringMatchType.EQUALS)); } /** *

* Returns a Playlist containing all the Songs * stored in this MusicCollection whose album attributes are * equal to the specified album title. *

* *

* The comparison is performed in a case-INsensitive manner. The * Songs in the returned Playlist MUST * be sorted in increasing order by disc number. If two Songs * have the same disc number, the song with the smaller track number MUST * occur before the other in the returned Playlist. *

* *

* Subsequent changes to the returned Playlist MUST NOT * affect the state of this MusicCollection. Likewise, * subsequent changes to the state of this MusicCollection * MUST NOT have any impact on the returned Playlist. *

* * @param albumTitle * The title of the album. * @return A Playlist containing all the Songs * stored in this MusicCollection whose album * attributes are equal to albumTitle. */ public Playlist getSongs(String albumTitle) { Playlist songSet; songSet = this.getSongs(this.factory.createAlbumFilter(albumTitle, StringMatchType.EQUALS)); songSet.sort(ComparatorFactory.ASCENDING_DISC_TRACK_COMPARATOR); return songSet; } /** *

* Returns a Playlist containing all the Songs * stored in this MusicCollection whose artist attributes are * equal to the specified artist name, and whose album attributes are equal * to the specified album title. *

* *

* * @param artistName * The name of the artist. * @param albumTitle * The title of the album. * @return A Playlist containing all the Songs * stored in this MusicCollection whose artist * attributes are equal to artistName, and whose * album attributes are equal to albumTitle. */ public Playlist getSongs(String artistName, String albumTitle) { ArrayList filterList; SongFilter filter; Playlist songSet; filterList = new ArrayList(); filterList.add(this.factory.createAlbumFilter(albumTitle, StringMatchType.EQUALS)); filterList.add(this.factory.createArtistFilter(artistName, StringMatchType.EQUALS)); filter = this.factory.createAndFilter(filterList); songSet = this.getSongs(filter); songSet.sort(ComparatorFactory.ASCENDING_DISC_TRACK_COMPARATOR); return songSet; } /** *

* Returns a Playlist containing all the Songs * stored in this MusicCollection that are accepted by the * specified SongFilter. In other words, this method returns * a Playlist containing all the Songs * currently stored in this MusicCollection for which the * accept() method defined in the SongFilter * class returns true when invoked on the specified * SongFilter object. *

* *

* The order in which the Songs appear in the returned * Playlist is undefined (that is, the Songs * can appear in any order). *

* *

* * @param filter * A SongFilter object; Songs * accepted by this SongFilter are included in the * returned PlayList. * @return A Playlist containing all Songs * currently stored in this MusicCollection that are * accepted by filter. */ public Playlist getSongs(SongFilter filter) { Playlist songSubset; songSubset = new Playlist(); for (Song song : this.songs) { if (filter.accept(song)) { songSubset.add(song); } } return songSubset; } /** *

* Returns the Song contained in this * MusicCollection whose path attribute is equal to the * specified File, as defined by the equals() * method of the File class, if such a Song * exists within the MusicCollection. If this * MusicCollection contains no such object, this method * returns null. *

* * @param path * The path of a Song potentially stored in this * MusicCollection. * @return The Song object contained in this * MusicCollection whose path attribute is equal to * path if one exists, null otherwise. */ public Song getSong(File path) { Playlist oneSong; oneSong = this.getSongs(this.factory.createPathFilter(path)); return (oneSong.isEmpty() ? null : oneSong.get(0)); } /** *

* Adds the specified Song to this * MusicCollection. *

* *

* If the specified Song is null, or if this * MusicCollection contains a Song whose path * attribute is equal to the path attribute of the specified * Song, then this Song MUST NOT be * added to this MusicCollection, and the latter therefore * does not change. *

* * @param song * The Song to be added to this * MusicCollection. */ public void add(Song song) { if ((song != null) && (this.getSong(song.getFilePath()) == null)) { this.songs.add(song); } } /** * Adds the Songs contained in the specified * ArrayList into this MusicCollection. * *

* If the specified ArrayList contains null * elements, these null elements MUST NOT be added to * this MusicCollection. Likewise, if the specified * ArrayList contains Songs whose path * attributes are equal to the path attribute of Songs * contained this MusicCollection, these Songs * MUST NOT be added to this MusicCollection. * However, non-null Songs contained in the * specified ArrayList whose path attributes are not equal to * the path attributes of Songs currently stored in this * MusicCollection MUST be added to the latter. *

* * @param songList * An ArrayList of Songs to be * added to this MusicCollection. */ public void addAll(ArrayList songList) { for (Song song : songList) { this.add(song); } } /** * Adds the Song objects contained in the specified array of * Songs into this MusicCollection. * *

* If the specified array contains null elements, these * null elements MUST NOT be added to this * MusicCollection. Likewise, if the specified array * contains Songs whose path attributes are equal to the * path attribute of Songs contained this * MusicCollection, these Songs MUST NOT * be added to this MusicCollection. However, non-null Songs * contained in the specified array whose path attributes are not equal to * the path attributes of Songs currently stored in this * MusicCollection MUST be added to the latter. *

* * @param songArray * An array of Songs to be added to this * MusicCollection. */ public void addAll(Song[] songArray) { for (Song song : songArray) { this.add(song); } } }