【新手问题】Class 之间的互相调用以及constructor的使用

[javaleave]

现在要建一个MusicCollection class, 每个collection 需要至少三张专辑（3 albums), 我们需要显示出collection 并且允许用户去选择专辑特定设置。
要求：
1. 一个static Scanner object 用于整个class.
2. main method 需要以下功能：
a. 至少有三首歌（3 Songs), 每个版本的Song Constructors 至少用一次
b. 为每首歌创造出一个Albums（create an Album for each of the songs),每个版本的Album constructors 至少用一次
c. 有一个主循环需要做到以下步骤：
-打印显示出所有的专辑（Album)的数字排序（numbered ordering),需要用albums getter完成这个
-允许用户去选择那张专辑（Album)他想去使用，接着对那张专辑（Album) call albumOptions method
-这个循环必须终止如果用户输入0为专辑选择上（album selection)
-其他情况下继续这个循环
d.创建一个public static void albumOptions(Album variableName) {...}---->(题外话为什么一定是static?)
这个method 接收Album object, 可以随意定义它的名字，但必须有以下功能：
- 打印出专辑信息， 使用Album的 toString method
- 提示并且允许用户去挑选以下的选项：
>Get Favorite Track: 打印出歌曲（Song) 的信息（使用song's toString method)和favoriteTrack 在这个专辑中，包括track的数字
>Change genre:允许用户去改变Album 的genre. 这必须与歌(Song)的genre一起改变
>Return: 允许用户去返回到主循环
3.期间会使用到的shadowing variable, 有时需要用scanner.nextLine()

我写的Album.java 和Song.java 现在附上。对MusicCollection实在很头疼

Song.java

public class Song {
/*
* @parama title--songs' title
* @parama genre--songs' genre
* @parama artist--songs' artist
*/
private String title;
private String artist;
private String genre;

/*
* Constructs a song
* @param song is the song's title
* @param artist is the song's artist
* @param genre is the song's genre type
*/
public Song(String title, String artist, String genre){
this.title = title;
this.artist = artist;
this.genre = genre ;

}

public Song(String title, String artist){
String unknown= genre;
}

public String getTitle(){
return title;
}

public String getArtist(){
return artist;
}

public String getGenre(){
return genre;
}

public void setGenre(String genre){
this.genre=genre;
}

/*
* Return a String represent the song information
*
*/
public String toString(){
return title+"," + artist + ","+ genre;
}


}

Album.java

public class Album {
/*
* @param the title, artist, genre of album
* @param the list of favorite track number
*/

private String title;
private String artist;
private String genre;
private Song favoriteTrack;
private int trackNumber;
private static int numAlbums;
/*
* @param the album's number
*/
public static int numAlbum (int numAlbum){
return numAlbum;
}

/*Constructs an album
* @param title the title of album
* @param artis the artis of favorite track
* @param favoritetrack is a song's track
*/

public Album(String title, Song favoriteTrack, int trackNumber){
this.title= title;
this.favoriteTrack= favoriteTrack;
this.trackNumber= trackNumber;
artist = favoriteTrack.getArtist();
genre = favoriteTrack.getGenre();
int numAlbum = 0;
numAlbum ++;

}

public Album(String title, Song favoriteTrack){
this(title,favoriteTrack,1);
}

public String getTitle(){

return title;
}

public Song getfavoriteTrack(){
return favoriteTrack;
}

public int gettrackNumber(){
return trackNumber;
}

public void setGenre(String genre){

this.genre= genre;
}

/*
* Return a String represent the album
*
*/
public String toString(){
return "\""+title + "," + favoriteTrack.toString() +","+ trackNumber;
}

}

我写了一些MusicCollection.java,但大致的方向还是没找到。希望大家给予帮助！

import java.util.*;

public class MusicCollection {

private static String albumTitle;
private static int numAlbum;
public static Scanner{
Scanner scan = new Scanner(System.in);
}
public static void main(String[] args){
Album a = new Album("Beyond",new Song("I love Mars"), 4);
Album b = new Album("Flying", new Song("Who's care"), 2);
Album c = new Album("Complicated",new Song("Everybody"),5);

/*
* @param scan is an input parameter.
*/
Scanner scan = new Scanner(System.in);
albumTitle = Album.getTitle(scan.nextLine());
numAlbum = Album.numAlbum(scan.nextInt());
for (int =0; i < numAlbum; i ++){
Album =
}

}

public static void albumOpitions(Album variableName){
System.out.println(Album.toString());

}
}

谢谢！！请大家帮我看看这个MusicCollection余下该怎么写

[javaleave]

求助啊～大家帮我看看如何解这道题！谢谢了！

[javaleave]

在线等啊。求帮助！！！

[K-2SO]

LOL

[K-2SO]

public class Song {
	private String title, artist, genre;
	public Song(String title, String artist, String genre){
		this.title = title;
		this.artist = artist;
		this.genre = genre;
	}
	public Song(String title, String artist){
		this.title = title;
		this.artist = artist;
		genre = "unknown";
	}
	public void setTitle(String title){
		this.title = title;
	}
	public void setArtist(String artist){
		this.artist = artist;
	}
	public void setGenre(String genre){
		this.genre = genre;
	}
	public String getTitle(){
		return title;
	}
	public String getArtist(){
		return artist;
	}
	public String getGenre(){
		return genre;
	}
	public String toString(){
		return artist + " " + "-" + " " + title + "," + " " + "Genre:" + " " + genre;
	}
}

[K-2SO]

import java.util.Scanner;

public class Album {
	private String title, artist, genre;
	private Song favoriteTrack;
	private int trackNumber;
	static int numAlbums = 0;
	public Album(String title, Song favoriteTrack, int trackNumber){
		this.title = title;
		artist = favoriteTrack.getArtist();
		genre = favoriteTrack.getGenre();
		this.favoriteTrack = favoriteTrack;
		this.trackNumber = trackNumber;
		numAlbums ++;
	}
	public Album(String title, Song favoriteTrack){
		this.title = title;
		artist = favoriteTrack.getArtist();
		genre = favoriteTrack.getGenre();
		this.favoriteTrack = favoriteTrack;
		trackNumber = 1;
		numAlbums ++;
	}
	public String getTitle(){
		return title;
	}
	public String getFavoriteTrack(){
		return favoriteTrack.toString();
	}
	public int getTrackNumber(){
		return trackNumber;
	}
	public int getNumberAlbums(){
		return numAlbums;
	}
	public void setGenre(String genre){
		this.genre = genre;
		favoriteTrack.setGenre(genre);
	}
	public void setTitle(String title){
		this.title = title;
	}
	public void setArtist(String artist){
		this.artist = artist;
		favoriteTrack.setArtist(artist);
	}
	public String toString(){
		return artist + " " + "-" + " " + title + "," + " " + "Genre:" + " " + genre;
	}
}