Here you can find the source of isNotEmpty(Collection> colecao)
public static boolean isNotEmpty(Collection<?> colecao)
//package com.java2s; //License from project: Open Source License import java.util.Collection; public class Main { public static boolean isNotEmpty(Collection<?> colecao) { return colecao != null && !colecao.isEmpty(); }//from ww w . j ava2s . com public static boolean isEmpty(Collection<?> colecao) { return colecao == null || colecao.isEmpty(); } public static boolean isEmpty(String string) { return string == null || string.isEmpty(); } }