Here you can find the source of removeAll(Collection
@SuppressWarnings("unchecked") public static <E, T extends E> Collection<E> removeAll(Collection<E> c, T... array)
//package com.java2s; /**/*from w w w . ja va2 s .c o m*/ * JLibs: Common Utilities for Java * Copyright (C) 2009 Santhosh Kumar T <santhosh.tekuri@gmail.com> * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. */ import java.util.*; public class Main { /** * Removes objects in array to the given collection * * @return the same collection which is passed as argument */ @SuppressWarnings("unchecked") public static <E, T extends E> Collection<E> removeAll(Collection<E> c, T... array) { for (T obj : array) c.remove(obj); return c; } }