Here you can find the source of getFileSize(long fileSize)
public static String getFileSize(long fileSize)
//package com.java2s; /*//from ww w . j a va2 s. c o m * Copyright (C) 2003-2014 eXo Platform SAS. * * This is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as * published by the Free Software Foundation; either version 3 of * the License, or (at your option) any later version. * * This software 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this software; if not, write to the Free * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA, or see the FSF site: http://www.fsf.org. */ import java.text.DecimalFormat; public class Main { public static String getFileSize(long fileSize) { int freeUnit; for (freeUnit = 0; fileSize >= 100; freeUnit++) { fileSize /= 1024; } DecimalFormat decFormat = new DecimalFormat("0.0"); String doubleString = decFormat.format(fileSize); StringBuffer buffer = new StringBuffer(); buffer.append(doubleString); switch (freeUnit) { case 0: buffer.append("B"); break; case 1: buffer.append("KB"); break; case 2: buffer.append("MB"); break; case 3: buffer.append("GB"); break; case 4: buffer.append("TB"); break; default: buffer.append("err"); break; } return buffer.toString(); } }