java - 即使在程序执行后如何继续请求控制台输入运行

Question

我试图在从控制台获取用户输入后执行程序。 [下面的代码块]。但是，我不想在程序执行完成后终止。我希望控制台在执行完成后始终询问我 INITIAL_MESSAGE。实际上，在执行程序后，我希望控制台再次询问我 INTIAL_MESSAGE，以便我可以再次根据需要输入输入并再次执行程序。我实际上是在这个方法中调用interactor()，从main方法作为起点。请告诉我如何实现这一目标

public class ConsoleInteraction {

    /**
     * @param args
     */

    public static int numberOfJavaTrainees ;
    public static int numberOfPHPTrainees ;
    Barracks trainingBarrack = new Barracks();


    public void interactor() throws IOException {

        //reading capability from the consolemessages properties file

        ResourceBundle bundle = ResourceBundle.getBundle("resources/consolemessages");

        // Create a scanner so we can read the command-line input
        Scanner scanner = new Scanner(System.in);

        // Prompt for training or viewing camp       
        System.out.print(bundle.getString("INITIAL_MESSAGE"));
        //Get the preference as an integer
        int preference = scanner.nextInt();


        //Show options based on preference
        if(preference == 1)
        {
            //System.out.println("Whom do you want to train?\n 1.Java Guy \n 2.PHP Guy \n 3.Mix \n Enter You preference:");
            System.out.print(bundle.getString("WHO_TO_TRAIN"));
            int traineepreference = scanner.nextInt();
            if (traineepreference == 1)
                {
                //System.out.println("How many Java guys you want to train ? : ");
                System.out.print(bundle.getString("HOW_MANY_JAVA"));
                numberOfJavaTrainees = scanner.nextInt();
                trainingBarrack.trainTrainees(numberOfJavaTrainees, 0);

                }
            else if (traineepreference == 2)
                {
                //System.out.println("How many PHP guys you want to train ? : ");
                System.out.print(bundle.getString("HOW_MANY_PHP"));
                numberOfPHPTrainees = scanner.nextInt();
                trainingBarrack.trainTrainees(0, numberOfPHPTrainees);

                }
            else if (traineepreference == 3)
                {
                System.out.print(bundle.getString("HOW_MANY_JAVA"));
                numberOfJavaTrainees = scanner.nextInt();
                System.out.print(bundle.getString("HOW_MANY_PHP")); 
                numberOfPHPTrainees = scanner.nextInt();
                trainingBarrack.trainTrainees(numberOfJavaTrainees, numberOfPHPTrainees);

                }
            else 
                {
                    System.out.print(bundle.getString("ERROR_MESSAGE1"));
                }
        }
        else if (preference == 2)
        {
            System.out.println("Showing Camp to You");
            System.out.println("Java trained in Trainee Camp : "+ TraineeCamp.trainedJavaGuys);
            System.out.println("PHP trained in Trainee Camp : "+ TraineeCamp.trainedPHPGuys);

        }

        else 
        {
                System.out.print(bundle.getString("ERROR_MESSAGE2"));
        }   

        scanner.close();
    }
}

Answer 1

考虑将这些更改快速起草到您的类(class)中。可能无法编译。可能无法按您的计划进行。

我认为你应该改变的一些要点:

• 使用常量作为选择值。使您的代码更易于阅读。
• 在方法外部初始化 Bundle 和 Scanner。可能会被重复使用。

• 不要在 if-else-if 级联中编写冗长的代码部分，而是调用其中的方法 - 从而大大提高可读性

  public class ConsoleInteraction  {
  
    public static int numberOfJavaTrainees ;
    public static int numberOfPHPTrainees ;
  
    //Don't read that every time...
    ResourceBundle bundle = ResourceBundle.getBundle("resources/consolemessages");
  
  
    public static void main(String[] args) {
      //Moving Scanner out of loop
      try {
          Scanner scanner = new Scanner(System.in);
          ConsoleInteraction ci = new ConsoleInteraction();
          //Loop until this returns false
          while(ci.interactor(scanner)) {
              System.out.println("=== Next iteration ===");
          }
      } catch (IOException e) {
          e.printStackTrace();
      }
  
   }
  
  //Constant values to make code readable
  public final static int PREF_TRAINING = 1;
  public final static int PREF_SHOW_CAMP = 2;
  public final static int PREF_QUIT = 99;
  
  public boolean interactor(Scanner scanner) throws IOException {
  
      // Prompt for training or viewing camp       
      System.out.print(bundle.getString("INITIAL_MESSAGE"));
      //Get the preference as an integer
      int preference = scanner.nextInt();
  
      //Show options based on preference.
  
      if(preference == PREF_TRAINING) {
          //LIKE YOU DID BEFORE OR calling method:
          readTraining(scanner);
      } else if (preference == PREF_SHOW_CAMP) {
          //LIKE YOU DID BEFORE OR calling mathod:
          showCamp();
      } else if (preference == PREF_QUIT) {
          //Last loop
          return false;
      }  else {
          System.out.print(bundle.getString("ERROR_MESSAGE2"));
      }   
      //Next loop
      return true;
  }
  }