Here you can find the source of isNotEmpty(Collection> c)
public static boolean isNotEmpty(Collection<?> c)
//package com.java2s; //License from project: Apache License import java.util.Collection; import java.util.Map; public class Main { public static boolean isNotEmpty(Collection<?> c) { if (c == null) { return false; }/*www. ja v a 2 s .c om*/ return !c.isEmpty(); } public static boolean isNotEmpty(Map<?, ?> map) { if (map == null) { return false; } return !map.isEmpty(); } }