001// *************************************************************************************************************************** 002// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file * 003// * distributed with this work for additional information regarding copyright ownership. The ASF licenses this file * 004// * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance * 005// * with the License. You may obtain a copy of the License at * 006// * * 007// * http://www.apache.org/licenses/LICENSE-2.0 * 008// * * 009// * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an * 010// * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the * 011// * specific language governing permissions and limitations under the License. * 012// *************************************************************************************************************************** 013package org.apache.juneau.internal; 014 015import java.util.*; 016 017/** 018 * Combination of a {@link LinkedList} and <code>IdentitySet</code>. 019 * 020 * <ul class='spaced-list'> 021 * <li> 022 * Duplicate objects (by identity) will be skipped during insertion. 023 * <li> 024 * Order of insertion maintained. 025 * </ul> 026 * 027 * <h5 class='section'>Notes:</h5> 028 * <ul class='spaced-list'> 029 * <li> 030 * This class is NOT thread safe, and is intended for use on small lists. 031 * </ul> 032 * 033 * @param <T> Entry type. 034 */ 035public class IdentityList<T> extends LinkedList<T> { 036 037 private static final long serialVersionUID = 1L; 038 039 @Override /* List */ 040 public boolean add(T t) { 041 for (T t2 : this) 042 if (t2 == t) 043 return false; 044 super.add(t); 045 return true; 046 } 047 048 @Override /* List */ 049 public boolean contains(Object t) { 050 for (T t2 : this) 051 if (t2 == t) 052 return true; 053 return false; 054 } 055}