使用 while 或 do while 循环从用户输入创建文件夹

Question

我在使用 while、do-while 循环创建多个文件夹时遇到问题 Java.I 尝试创建文件但我没有问题，但文件夹，不同的故事。我正在使用扫描仪，BufferedReader.The 问题是，它的行为真的很奇怪。如果我输入至少 3 个文件夹名称，它通常只会首先创建，或者跳过第二个并首先创建 third.At 最后它不会接受我的 "Exit" 作为我的完成点它只会创建名为 "Exit" 并等待更多输入。我已经在 google 中进行了搜索，但没有找到任何有用的东西 me.Here 是代码，（案例 AddShelf）：`package library;

public class Administrator {

    public static String help_msg = "[ Main Menu ]\r\n\r\nAddBook\r\nRemoveBook\r\nBookInfo\r\nAddShelf\nRemoveShelf\r\nShelfInfo";
    private static final DateFormat sdf = new SimpleDateFormat("dd/MM/yyyy HH:mm:ss");

    public static void main(String[] args)throws IOException {
                        Date date = new Date();
                        System.out.println(sdf.format(date));
                System.out.println("Welcome to my book library\r\n\r\n"+"ADMINISTRATOR\r\n\r\n"+help_msg+"\r\n");

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String operate = br.readLine();

    do {
        switch(operate) {
        case"AddBook":
            //chose shelf,add new book  
        case"RemoveBook":
            //chose shelf,remove book
        case"BookInfo":
            //chose shelf,chose book,show book info
        case"AddShelf":
            try {
                System.out.println("Enter the name of the shelf:");
                Scanner sc = new Scanner(System.in);
                String files = sc.nextLine();
                do {
                    File dir = new File("D:\admir\MyBookLibrary\"+files);
                    dir.mkdirs();
                }while(!"Exit".equals(sc.next()));
                System.out.println("Shelf added successfully!");
            }catch(Exception e) {
                System.err.println("Unable to create new Shelf!");
            }
        case"RemoveShelf":
            //remove shelf
        case"ShelfInfo":
            //shelf info
            default:
                //if incorrect operation is entered,print message,back to choosing operations
        }
    }while(!"Exit".equals(br.readLine()));

    }
}

Answer 1

我检查了代码do while有点困难，所以我把它改成了while try this code。

  import java.io.File;
  import java.text.DateFormat;
  import java.text.SimpleDateFormat;
  import java.util.Date;
  import java.util.Scanner;

  public class Administrator {

    public static String help_msg = "[ Main Menu ]\r\n\r\nAddBook\r\nRemoveBook\r\nBookInfo\r\nAddShelf\nRemoveShelf\r\nShelfInfo";
    private static final DateFormat sdf = new SimpleDateFormat("dd/MM/yyyy HH:mm:ss");

    public static void main(String[] args){
      Date date = new Date();
      System.out.println(sdf.format(date));
      System.out.println("Welcome to my book library\r\n\r\n"+"ADMINISTRATOR\r\n\r\n"+help_msg+"\r\n");

      Scanner sc = new Scanner(System.in);
      String operate;

      while(!"Exit".equals(operate = sc.nextLine())){
        switch(operate) {
          case"AddBook":
            //chose shelf,add new book
          case"RemoveBook":
            //chose shelf,remove book
          case"BookInfo":
            //chose shelf,chose book,show book info
            break;
          case"AddShelf":
            try {
              System.out.println("Enter the name of the shelf:");
              String files;
              while(!"Exit".equals(files = sc.nextLine())){
                File dir = new File("D:\admir\MyBookLibrary\"+files);
                dir.mkdirs();
                System.out.println(files+"Shelf added successfully!");
                System.out.println("Enter another name of the shelf:");
              }
              return;
            }catch(Exception e) {
              System.err.println("Unable to create new Shelf!");
            }
            break;
          case"RemoveShelf":
            //remove shelf
          case"ShelfInfo":
            //shelf info
          default:
            //if incorrect operation is entered,print message,back to choosing operations
        }
      }

    }
  }

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