Here you can find the source of getFileSize(File file)
public static String getFileSize(File file)
//package com.java2s; /*/* w w w. j a va 2 s. c o m*/ * FileUtilities.java * * Copyright (C) 2003 Robert McKinnon * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ import java.io.File; public class Main { public static String getFileSize(File file) { String size; long bytes = file.length(); if (bytes == 0) { size = ""; } else if (bytes < 1024) { size = bytes + "b"; } else { float kb = bytes / 1024F; if (kb < 1024) { kb = Math.round(kb * 10) / 10F; size = kb + "kb"; } else { float mb = kb / 1024; mb = Math.round(mb * 10) / 10F; size = mb + "mb"; } } return size; } }