Java tutorial
/* * Copyright 2013 The Netty Project * * The Netty Project licenses this file to you under the Apache License, * version 2.0 (the "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. */ package io.netty.util.internal; import java.io.Serializable; import java.util.AbstractSet; import java.util.Iterator; import java.util.concurrent.ConcurrentMap; /** * @deprecated For removal in Netty 4.2. Please use {@link ConcurrentHashMap#newKeySet()} instead */ @Deprecated public final class ConcurrentSet<E> extends AbstractSet<E> implements Serializable { private static final long serialVersionUID = -6761513279741915432L; private final ConcurrentMap<E, Boolean> map; /** * Creates a new instance which wraps the specified {@code map}. */ public ConcurrentSet() { map = PlatformDependent.newConcurrentHashMap(); } @Override public int size() { return map.size(); } @Override public boolean contains(Object o) { return map.containsKey(o); } @Override public boolean add(E o) { return map.putIfAbsent(o, Boolean.TRUE) == null; } @Override public boolean remove(Object o) { return map.remove(o) != null; } @Override public void clear() { map.clear(); } @Override public Iterator<E> iterator() { return map.keySet().iterator(); } }