如何继续制作 - BlueJ Java文件管理器

Question

我知道这是一个noob程序，但我慢慢地感到困惑。 '下'功能将像CD一样行事，“上”功能将像CD一样行事。

我不知道如何让用户创建文件或文件夹。我试图使用arrayLists而不是数组，但无法排除错误。任何帮助，将不胜感激。

import java.util.Scanner; 
    class FileManager { 
    //array of arrays will go here 
    String Dir[] = {"UserOne"}; 
    String SystemFolders [] = {"Documents","","",}; 
    String SubFiles [] = {"","","","","",""}; 
    String Nav [][] = { Dir, SystemFolders, SubFiles}; 
    int levelCounter = 0; 
    public void main(String[]args) { 
     Scanner sc = new Scanner (System.in); 
     System.out.println("Enter a command"); 
     String command = sc.next(); 
      if (command.compareTo("down") == 0) 
       down(); 
      //else if is on the way 
    } 
    void down() { 
     //This will execute when the command is 'down' 
     System.out.println(Nav[++levelCounter]); 
    } 
    void up() { 
     //This will execute when the command is 'up'. It acts like cd.. 
     System.out.println(Nav[--levelCounter]); 
    } 
} 

Answer 1

如果这是你的程序的入口点，那么你需要声明你main方法为静态，像这样

然后访问您的主要方法，在你的FileManager类的方法你需要在你的main方法中创建你的类的一个实例。像这样

public static void main(String[]args) { 
    FileManager fm = new FileManager(); // Creates an instance 
    Scanner sc = new Scanner (System.in); 
    System.out.println("Enter a command"); 
    String command = sc.next(); 
    if (command.equals("down")) // equals will suffice in this case 
           // or equalsIgnoreCase() if you dont want case to be a problem 
     fm.down(); // Notice now this calls the down method from the instance 
    //else if is on the way 
} 

然后看看这例子create files或这create folders