JAVA->查询并显示输入根目录下全部的文件所在目录路径

public static boolean qf(File f,boolean a){
      boolean b=false;
   if(a==true){
      File[] fl=f.listfile();
   for(File ffl:fl){
    if(ffl.isDirect){
    b=ffl.getTotalspace>0;
    if(b==true){ System.out.println("This's not a Null Direct: "+ffl);
    qf(ffl,b); }
    }
    else System.out.println("This's a Null Direct: "+ffl);
   } }
   else System.out.println("This is a file: "+fl);
}