Question

Using listAllFiles as a guide, write a method that has one File argument: if the argument is a directory, the method returns the total number of files below it. If the argument represents a file, the method just returns 1. public static int countFiles(File f)  

import java.io.File;

public class FileLister
{
  public static void main(String[] args)
  {
    // Choose the directory you want to list.
    // If running in Eclipse, "." will just be the current project directory.
    // Use ".." to list the whole workspace directory, or enter a path to
    // some other directory.
    File rootDirectory = new File(".");

    listAllFiles(rootDirectory);
  }
  
  /**
   * Print the names of all items in the hierarchy located under 
   * a given directory. If the given File object is not a directory, 
   * just prints the file's name.
   */
  public static void listAllFiles(File f)
  {
    if (!f.isDirectory())
    {
      // Base case: f is a file, so just print its name
      System.out.println(f.getName());
    }
    else
    {
      // Recursive case: f is a directory, so go through the 
      // files and directories it contains, and recursively call
      // this method on each one
      System.out.println("+ " + f.getName());
      File[] files = f.listFiles();
      for (int i = 0; i < files.length; ++i)
      {
        listAllFiles(files[i]);
      }
    }
  }
}

Answer 1

import java.io.File;

public class FileLister
{
   public static void main(String[] args)
   {
       // Choose the directory you want to list.
       // If running in Eclipse, "." will just be the current project directory.
       // Use ".." to list the whole workspace directory, or enter a path to
       // some other directory.
       File rootDirectory = new File(".");

       listAllFiles(rootDirectory);
   }

   public static int countFiles(File f) {

       if(f.isFile())
           return 1;
       else{
           return f.list().length;
       }
   }

   /**
   * Print the names of all items in the hierarchy located under
   * a given directory. If the given File object is not a directory,
   * just prints the file's name.
   */
   public static void listAllFiles(File f)
   {
       if (!f.isDirectory())
       {
           // Base case: f is a file, so just print its name
           System.out.println(f.getName());
       }
       else
       {
           // Recursive case: f is a directory, so go through the
           // files and directories it contains, and recursively call
           // this method on each one
           System.out.println("+ " + f.getName());
           File[] files = f.listFiles();
           for (int i = 0; i < files.length; ++i)
           {
               listAllFiles(files[i]);
           }
       }
   }
}