Here you can find the source of numberFormat(int i)
public static String numberFormat(int i)
//package com.java2s; //License from project: Apache License import java.text.DecimalFormat; import java.text.NumberFormat; public class Main { private static final NumberFormat NF = new DecimalFormat("##,###"); private static final NumberFormat MEM_FMT = new DecimalFormat("##,###.##"); public static String numberFormat(int i) { return NF.format(i); }// ww w. j av a 2 s. c om public static String numberFormat(double d) { return NF.format(d); } private static String format(long bytes) { double val = bytes; int mag = 0; while (val > 1024) { val = val / 1024; mag++; } String formatted = MEM_FMT.format(val); switch (mag) { case 0: return formatted + " bytes"; case 1: return formatted + " kb"; case 2: return formatted + " Mb"; case 3: return formatted + " Gb"; default: return "WTF?"; } } }