import java.io.File;import 
java.io.IOException;public 
class Main {
    static int i = 0;    
    public static void main(String[] args) throws IOException {
        File currentDir = new File(".");        
        System.out.println(currentDir.getCanonicalFile());        
        listDir(currentDir.getCanonicalFile());    
    }

    static void listDir(File dir) {
        // TODO: 递归打印所有文件和子文件夹的内容        
        String s ="";        
        for(int j =0;j<i;j++){
            s=s+"  ";        
        }
        File[] fs = dir.listFiles();        
        if (fs != null) {
            for (File f : fs) {
                if (f.isDirectory()) {
                    System.out.println(s+f.getName() + "/");                    
                    i++;                    
                    listDir(f);                    
                    i--;                
                    }
                if (!f.isDirectory()) System.out.println(s+f.getName());            
              }
        }
    }

}