1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, 13 * software distributed under the License is distributed on an 14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 15 * KIND, either express or implied. See the License for the 16 * specific language governing permissions and limitations 17 * under the License. 18 * 19 */ 20 package org.apache.mina.util; 21 22 import java.util.AbstractSet; 23 import java.util.Collection; 24 import java.util.IdentityHashMap; 25 import java.util.Iterator; 26 import java.util.Map; 27 import java.util.Set; 28 29 /** 30 * An {@link IdentityHashMap}-backed {@link Set}. 31 * 32 * @author The Apache Directory Project (mina-dev@directory.apache.org) 33 * @version $Rev: 555855 $, $Date: 2007-07-13 05:19:00 +0200 (Fri, 13 Jul 2007) $ 34 */ 35 public class IdentityHashSet extends AbstractSet { 36 private final Map delegate = new IdentityHashMap(); 37 38 public IdentityHashSet() { 39 } 40 41 public IdentityHashSet(Collection c) { 42 addAll(c); 43 } 44 45 public int size() { 46 return delegate.size(); 47 } 48 49 public boolean contains(Object o) { 50 return delegate.containsKey(o); 51 } 52 53 public Iterator iterator() { 54 return delegate.keySet().iterator(); 55 } 56 57 public boolean add(Object arg0) { 58 return delegate.put(arg0, Boolean.TRUE) == null; 59 } 60 61 public boolean remove(Object o) { 62 return delegate.remove(o) != null; 63 } 64 65 public void clear() { 66 delegate.clear(); 67 } 68 }