Here you can find the source of max(Collection
public static double max(Collection<Double> doubles)
//package com.java2s; /* /* w w w. jav a2s .c o m*/ * This file is part of Transitime.org * * Transitime.org is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License (GPL) as published by * the Free Software Foundation, either version 3 of the License, or * any later version. * * Transitime.org 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 Transitime.org . If not, see <http://www.gnu.org/licenses/>. */ import java.util.Collection; public class Main { public static double max(Collection<Double> doubles) { if (doubles.size() < 1) throw new IllegalArgumentException("No items in list"); Double max = 0d; for (Double doubleVal : doubles) { if (doubleVal > max) max = doubleVal; } return max; } }