Java tutorial
//package com.java2s; /* * ==================== * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. * * Copyright 2008-2009 Sun Microsystems, Inc. All rights reserved. * * The contents of this file are subject to the terms of the Common Development * and Distribution License("CDDL") (the "License"). You may not use this file * except in compliance with the License. * * You can obtain a copy of the License at * http://opensource.org/licenses/cddl1.php * See the License for the specific language governing permissions and limitations * under the License. * * When distributing the Covered Code, include this CDDL Header Notice in each file * and include the License file at http://opensource.org/licenses/cddl1.php. * If applicable, add the following below this CDDL Header, with the fields * enclosed by brackets [] replaced by your own identifying information: * "Portions Copyrighted [year] [name of copyright owner]" * ==================== * Portions Copyrighted 2018 ConnId */ import java.util.ArrayList; import java.util.Collections; import java.util.List; public class Main { /** * Returns a read-only list. The list is backed by the original so no copy is made. * * @param <T> The type of the list * @param list The list or null. * @return A read-only proxy on the original list. */ public static <T> List<T> asReadOnlyList(List<T> list) { if (list == null) { list = new ArrayList<>(); } return Collections.unmodifiableList(list); } }