求出目录的大小

package com.demo;

import java.io.File;
import java.util.Scanner;

public class Demo {

	public static long getSize(File file){
		long size = 0;
		if(file.isDirectory()){
			File[] files = file.listFiles();
			for (int i = 0; i < files.length; i++) {
				size += getSize(files[i]);
			}
		}
		else{
			size += file.length();
		}
		return size;
	}
	public static void main(String[] args) {
		System.out.println("Enter a directory or a file: ");
		Scanner input = new Scanner(System.in);
		String directory = input.nextLine();
		System.out.println(getSize(new File(directory)) + " bytes ");
	}
}