Java:找不到符号(构造函数)

时间:2012-02-17 01:07:15

标签: java constructor compiler-errors

新手在这里做Java作业。我有一个名为Album的类,它包含以下构造函数:

public class Album {

    private String title;
    private String artist;
    private String genre;
    private Song favoriteTrack;
    private int trackNumber;
    private static int numAlbums;

    //Constructors
    public Album(String title, Song favoriteTrack, int trackNumber) {
        this.title = title;
        this.favoriteTrack = favoriteTrack;
        this.trackNumber = trackNumber;
        artist = favoriteTrack.getArtist();
        genre = favoriteTrack.getGenre();
        numAlbums++;
    }

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

然后我有一个第二类MusicCollection,在其主方法中实例化Album类三次......

public static void main (String[] args) {...

    Album album1 = new Album("Debut", "Venus as a Boy", 3);
    Album album2 = new Album("Homework", "Around the World", 7);
    Album album3 = new Album("Ghost in the Machine", "Invisible Sun", 3);
    ...}

但是,当我尝试编译MusicCollection.java时,我收到错误:

cannot find symbol
symbol : constructor Album(java.lang.String,java.lang.String,int)
location : class Album

每次我尝试调用构造函数。 Album和MusicCollection类位于同一目录中,Album.java编译。 我想我正在做些傻事,但我无法弄清楚这一点。 任何帮助将不胜感激!

4 个答案:

答案 0 :(得分:6)

您定义的构造函数的第二个参数是Song,而不是String,但在您的main中,您尝试使用String作为第二个参数进行实例化。

答案 1 :(得分:1)

当您声明它应该收到String的实例时,您正在将Album传递给Song构造函数的第二个参数。

答案 2 :(得分:1)

Binyamin说的是什么!如果你有一个歌曲课,你需要说new Album("Debut", new Song("venus as a boy"), 3);之类的内容,具体取决于你的Song课程的工作方式,如果没有,请将歌曲改为字符串类型

答案 3 :(得分:0)

您正尝试使用2个字符串而不是字符串和某个类Song来实例化相册,也许您应该将构造函数更改为

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

或者这样做:

new Album("Debut", new Song("Venus as a boy"), 3);

或者歌曲已创建。