Here you can find the source of format(double value)
public static String format(double value)
//package com.java2s; /*//from ww w.j a v a 2 s .c o m 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 3 of the License, or (at your option) 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, see <http://www.gnu.org/licenses/>. Author: DarkLilac email:contact@darklilac.com */ import java.text.DecimalFormat; public class Main { public final static DecimalFormat FORMATTER = new DecimalFormat(); public static String format(double value) { final Double doubleValue = new Double(value); final int intValue = doubleValue.intValue(); if (intValue == value) { return Integer.toString(intValue); } return FORMATTER.format(value); } }