Java tutorial
//package com.java2s; import java.util.List; public class Main { /** * add distinct entry to list * * @param <V> * @param sourceList * @param entry * @return if entry already exist in sourceList, return false, else add it and return true. */ public static <V> boolean addDistinctEntry(List<V> sourceList, V entry) { return (sourceList != null && !sourceList.contains(entry)) ? sourceList.add(entry) : false; } }