java

import java.io.File;
import java.io.FilenameFilter;


public class file {

public static void main(String[] args) {
// TODO Auto-generated method stub
File f = new File("H:\\");
showDir(f, 0);


}
public static String getLevel(int level)
{
StringBuilder sb = new StringBuilder();
for(int x = 0; x < level; x ++)
{
sb.append("--");


}
return sb.toString();
}
public static void showDir(File f,int level)
{
System.out.println(getLevel(level) + f.getName());//getLevel(level),这里获得返回值
level ++;
File[]  files = f.listFiles();//把f里找到的东西放在file类型数组里
for(int i = 0; i < files.length; i ++)
{
if(files[i].isDirectory())
showDir(files[i],level);

System.out.println(files[i]);
}
}
}