如何使用控制台输入

Question

我试图在heroku上部署一个简单的Java程序，以从控制台获取输入。

代码如下：

public static void main(String[] args) throws Exception {
    Scanner kboard = new Scanner(System.in);
    System.out.println("\u000C"); 
    String selection;
    boolean video = true;
    int cnt = 0;

    while(video){
       System.out.print("Enter cat or emu : ");           
       selection = kboard.nextLine();
       if (selection.equals("emu")){
        Desktop.getDesktop().open(new File("c:\\emu.mp4"));
        Thread.sleep(14000);            
       }else if(selection.equals("cat")){
        Desktop.getDesktop().open(new File("c:\\Cat Boarding.mp4"));
        Thread.sleep(12000);  
       }
       System.out.println();
       cnt++;
       if (cnt == 3) video = false;
    }
    kboard.close();   

}

这是我得到的错误：

Enter cat or emu : Exception in thread "main" java.util.NoSuchElementException: No line found
2019-03-27T23:50:37.010138+00:00 app[web.1]: at java.util.Scanner.nextLine(Scanner.java:1540)
2019-03-27T23:50:37.010146+00:00 app[web.1]: at gen.P1.main(P1.java:18)