Here you can find the source of addAll(List
public static <T> List<T> addAll(List<T> xs, Collection<T> adds)
//package com.java2s; /*/* w w w . j a v a 2s.co m*/ * Copyright 2012 Andy Boothe * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.util.Collection; import java.util.List; public class Main { public static <T> List<T> addAll(List<T> xs, T... adds) { for (T add : adds) xs.add(add); return xs; } public static <T> List<T> addAll(List<T> xs, Collection<T> adds) { xs.addAll(adds); return xs; } }