Here you can find the source of addAll(Collection
public static <T> void addAll(Collection<T> collection, T... array)
//package com.java2s; /*//from w w w . j a v a2 s.c om * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ import java.util.*; public class Main { public static <T> void addAll(Collection<T> collection, T... array) { for (T t : array) { collection.add(t); } } }