从文本文件中搜索并显示ArrayList的内容

Question

我已经创建了一个歌曲类，其中包括歌曲（标题、艺术家、专辑）的数据成员。我已经有了一个包含不同歌曲的. txt文件，该文件存储在数组列表中。在我的主类中，功能之一是允许用户通过标题、艺术家或专辑搜索歌曲。

我的问题是，当用户输入某些标题时，搜索功能无法找到歌曲。例如，当我搜索歌曲标题“停留”时，它会找到它。但是，当我搜索名为“波西米亚狂想曲”的歌曲时，它找不到存储的歌曲。我知道它是存储的，因为当我显示列表时，它会显示出来。按唱片集或艺术家搜索时也会出现此问题。

我认为我的问题是由于我分割字符串的方式造成的，或者可能只是搜索函数本身的问题。

这是我的Song类，包含构造函数和Get/Set方法

public class Song {
    //Declaring all data members.
    private String title;
    private String artist;
    private String album;
    private String length;
    private static int songCounter = 0;

    //Constructors for Song class.      
    public Song(String title, String artist, String album, String length){
        this.title = title;
        this.artist = artist;
        this.album = album;
        this.length = length;
        songCounter++;
    }
    //Get and Set methods 
    public String getTitle(){
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getArtist(){
        return artist;
    }

    public void setArtist(String artist) {
        this.artist = artist;
    }

    public String getAlbum(){
        return album;
    }

    public void setAlbum(String album){
        this.album = album;
    }

    public String getLength(){
        return length;
    }

    public void setLength(String length){
        this.length = length;
    }

    public static int getSongCounter(){
        return songCounter;
    }
    //Overriding the toString() function.
    public String toString(){
        return title +" "+artist+" "+album+" "+length;
    }
 }

这是我的主课，从。txt文件，包括搜索方法

public class Library {

public static void main(String[] args) {
    ArrayList <Song> songList = new ArrayList <Song> ();
    boolean testInput = true;

    try{
        Scanner read = new Scanner (new File("SongList.txt"));
        do{
            String line = read.nextLine();
            String [] tokens = line.split(",");
            songList.add(new Song(tokens[0], tokens[1], tokens[2], tokens[3]));
        }while(read.hasNext());
        read.close();
    }catch (FileNotFoundException e){
        System.out.println("File not found.");
    }

    while ( testInput ){
        System.out.println("\nSelect a Function");
        System.out.println("1. Search Song");
        System.out.println("2. Add Song");
        System.out.println("3. Delete Song");
        System.out.println("4. Display Songs");
        System.out.println("5. Quit");

        switch (MenuInputCheck(1, 5)){

        case 1: searchSong(songList);
                break;
        case 2: addSong(songList);
                break;
        case 3: deleteSong(songList);
                break;
        case 4: displaySong(songList);
                break;
        case 5: testInput = false;
                break;
        }
    }
}

public static void searchSong(ArrayList <Song> songList){
    Scanner input = new Scanner(System.in);
    System.out.println("A. Search by Title");
    System.out.println("B. Search by Artist");
    System.out.println("C. Search by Album");

    boolean found = false;
    char menuOption = input.next().charAt(0);

    switch (menuOption) {
    case 'A':
    case 'a': System.out.print("Enter song title: ");
              String searchTitle = input.nextLine();
              for (Song i : songList){
                  if (i.getTitle().equals(searchTitle)){
                      System.out.println(i);
                      found = true;
                  }
              }
              if ( found != true ){
                  System.out.println("Song does not exist.");
              }
              break;
    case 'B':
    case 'b': System.out.print("Enter song artist: ");
              String searchArtist = input.nextLine();
              for (Song i : songList){
                  if (i.getArtist().equals(searchArtist)){
                      System.out.println(i);
                      found = true;
                  }
              }
              if ( found != true ){
                  System.out.println("Song does not exist.");
              }
              break;
    case 'C':
    case 'c': System.out.print("Enter song album: ");
              String searchAlbum = input.nextLine();
              for (Song i : songList){
                  if (i.getAlbum().equals(searchAlbum)){
                      System.out.println(i);
                      found = true;
                  }
              }
              if ( found != true ){
                  System.out.println("Song does not exist.");
              }
              break;
    }
}

Answer 1

更改String searchArtist=input。next（） 到字符串搜索艺术家=输入。nextLine（）

使用. Next（）您不能输入超过1个单词。当收到空格时，它将停止捕获进一步的输入。

我建议您将所有3种输入扫描方法更改为。nextLine（）。