使用扫描仪时出现NoSuchElement异常

原学程将引见应用扫描仪时涌现NoSuchElement异常的处置办法，这篇学程是从其余处所瞅到的，而后减了1些海外法式员的疑问与解问，愿望能对于您有所赞助，佳了，上面开端进修吧。

成绩描写

我试图在法式中应用Scanner第两次从掌握台夺取输出，但是在挪用另外一个办法中的第两个Scanner时，涌现了NoSuchElement异常。

假如我从运转startMenu()中增除startMenu()，它会正常运转，但是因为某种缘由，在运转后它会扔出异常。

 public class Garden {
 public static final Garden GARDEN = new Garden();
 //variable declartaions removed
 public static void main(String[] args) {
  if (null != args && 0 < args.length) {
GARDEN.fileName = args[0].trim();
  }
  if (GARDEN.fileName != null) {
GARDEN.fileReader(GARDEN.fileName);
  } else {
GARDEN.fileReader();
  }

  GARDEN.startMenu();
  int mainI = 0;
  while (mainI != 一000000) {
try {
 Thread.sleep(0);
} catch (InterruptedException e) {
}
GARDEN.daysWeather();
GARDEN.anotherDay();
mainI++;
  }
 }


 protected void fileReader() { // asks for file name for config file
  System.out.println("Enter File Name Please");
  Scanner cmdReader = null;
  String cmdInput = null;
  try {
cmdReader = new Scanner(System.in);
cmdInput = cmdReader.nextLine();
  } catch (NoSuchElementException noSuchElement) {
noSuchElement.printStackTrace();
fileReader();  //throwing error here
  }

  //code removed
 }



 protected void startMenu() {// modified code from ATM lab (week二)
 int selected = 0;
  //code removed 
  Scanner climateScanner = new Scanner(System.in);
  System.out.println("Select a number 一⑷");
  selected = climateScanner.nextInt();
  switch (selected) {
  case 一: // semiarid
weatherType = 一0; //一0% chance to rain
climateScanner.close();
break;
  case 二: // arid
weatherType = 二0; //五% chance to rain
climateScanner.close();
break;
  case 三:
weatherType = 五0; //二% chance to rain
tropicalWeather = true;
climateScanner.close(); 
break;
  case 四:
weatherType = 二0;//五% chance to rain 
storming = true;
climateScanner.close();
break;
  default:
System.out.println("Invalid Input try again");
startMenu(); //using Recursion to ask for input again
break;
  }
  //code removed
 }
}

推举谜底

 GARDEN.startMenu();// method id not a static one.

您不克不及以这类方法拜访它。您必需初初化类或者使您的办法成为动态办法。甚么是GARDEN？

肯定，您如今不妨编纂代码了。

再次

 GARDEN.fileReader(GARDEN.fileName); // you are parsing input argument 
  // But method in your class is no argument method

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