檢索隨機元素的ArrayList中

Question

public class guessMovies { 
private Random randomGenerator; 
public static void main(String[] args) throws IOException { 

    String MovieList = null; 

    try (BufferedReader br = new BufferedReader(new FileReader("Movielist.txt"))) { 

     while ((MovieList = br.readLine()) != null) { 
      ArrayList<String> MovieNames = new ArrayList<String>(); 
      MovieNames.addAll(Arrays.asList(MovieList)); 
      //System.out.println(MovieList); 
      System.out.println(MovieNames); 

      Random r = new Random(); 
      System.out.print(MovieNames.get(r.nextInt(MovieNames.size))); 
     } 
    } 

    catch(FileNotFoundException exception) { 
     System.out.println("I cannot find your file"); 
    } 
    //pick random movie 
} 

有人可以指導我如何選擇在Movielist文件隨機電影標題，我可以打印出整個列表，但我不知道如何選擇其中一個隨機。

Answer 1

您應該實例化一個ArrayList，讀取所有電影標題並將它們添加到列表中，然後使用Random.nextInt（）選擇並打印它。

Answer 2

嘗試是這樣的：

public class guessMovies { 

    public static void main(String[] args) throws IOException { 

     String MovieList; 
     ArrayList<String> MovieNames = new ArrayList<>(); 

     try (BufferedReader br = new BufferedReader(new FileReader("Movielist.txt"))) { 

      while ((MovieList = br.readLine()) != null) { 
       MovieNames.add(MovieList); 
      } 

      for(String movieName: MovieNames){ 
       System.out.println(movieName); 
      } 

      Random r = new Random(); 

System.out.println(MovieNames.get(r.nextInt(MovieNames.size()))); 
     } 

     catch(FileNotFoundException exception) { 
      System.out.println("I cannot find your file"); 
     } 
     //pick random movie 
    } 
}