Here you can find the source of format(double value)
public static String format(double value)
//package com.java2s; /**//from www . j a v a 2 s.c o m * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.text.DecimalFormat; public class Main { public static final DecimalFormat format = new DecimalFormat(",###.##"); public static String format(double value) { return format.format(value); } public static String format(double value, String f) { DecimalFormat _format = new DecimalFormat(f); return _format.format(value); } public static String format(long value) { return format.format(value); } }