Here you can find the source of hasAtLeastOneNotNullElement(Collection> collection)
public static boolean hasAtLeastOneNotNullElement(Collection<?> collection)
//package com.java2s; import java.util.Collection; public class Main { public static boolean hasAtLeastOneNotNullElement(Collection<?> collection) { if (collection == null) return false; if (collection.isEmpty()) return false; if (collection.contains(null)) return collection.size() > 1; return collection.size() > 0; }//from w ww . jav a2s . c o m }