Here you can find the source of isNullOrEmpty(T collection)
public static <T extends Collection<E>, E> boolean isNullOrEmpty(T collection)
//package com.java2s; //License from project: Apache License import java.util.Collection; public class Main { public static <T extends Collection<E>, E> boolean isNullOrEmpty(T collection) { return collection == null || collection.isEmpty(); }//from w w w . j a v a2s. co m }