Here you can find the source of mergeLists(List
public static <T> List<T> mergeLists(List<T> listA, List<T> listB, List<T> listC)
//package com.java2s; //License from project: Open Source License import java.util.ArrayList; import java.util.Collections; import java.util.List; public class Main { public static <T> List<T> mergeLists(List<T> listA, List<T> listB, List<T> listC) { List<T> returnList = new ArrayList<T>(listA); returnList.addAll(listB);/*from ww w . j a v a2 s. c o m*/ returnList.addAll(listC); return Collections.unmodifiableList(returnList); } }