Here you can find the source of max(Collection
public static String max(Collection<String> strs)
//package com.java2s; /*// w ww .ja v a2 s .c o m * Copyright 2013-2014 eBay Software Foundation * * Licensed 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.util.Collection; public class Main { public static String max(Collection<String> strs) { String max = null; for (String s : strs) { if (max == null || max.compareTo(s) < 0) max = s; } return max; } public static String max(String s1, String s2) { if (s1 == null) return s2; else if (s2 == null) return s1; else return s1.compareTo(s2) > 0 ? s1 : s2; } }