Java tutorial
//package com.java2s; import java.io.File; public class Main { private static long getFolderSize(File file) { long size = 0; File[] fileList = file.listFiles(); for (File aFileList : fileList) { if (aFileList.isDirectory()) { size = size + getFolderSize(aFileList); } else { size = size + aFileList.length(); } } return size; } }