Here you can find the source of subtract(List
public static List<String> subtract(List<String> a, List<String> b)
//package com.java2s; /******************************************************************************* * (c) Copyright 2016 Hewlett-Packard Development Company, L.P. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Apache License v2.0 which accompany this distribution. * * The Apache License is available at//from w w w. j a v a2s . c o m * http://www.apache.org/licenses/LICENSE-2.0 * *******************************************************************************/ import java.util.ArrayList; import java.util.List; public class Main { public static List<String> subtract(List<String> a, List<String> b) { List<String> result = new ArrayList<>(a); result.removeAll(b); return result; } }