//Sample11_01.java

import java.io.File;

class Sample11_01{
    public static void main(String[] args){
        File dir = new File("parent");
        File[] files = dir.listFiles();
        if(files!=null){
            for(File file : files){
                System.out.println(file.getPath());
            }
        }else{
            System.out.println("null");
        }

    }
}