org.apache.mina.util.ConcurrentHashSet Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF 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 org.apache.mina.util;
import java.util.Collection;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
/**
* A {@link ConcurrentHashMap}-backed {@link Set}.
*
* @param The type of the element stored in the set
*
* @author Apache MINA Project
*/
public class ConcurrentHashSet extends MapBackedSet {
private static final long serialVersionUID = 8518578988740277828L;
/**
* Creates a new instance of ConcurrentHashSet
*/
public ConcurrentHashSet() {
super(new ConcurrentHashMap());
}
/**
* Creates a new instance of ConcurrentHashSet, initialized with
* the content of another collection
*
* @param collection The collection to inject in this set
*/
public ConcurrentHashSet(Collection collection) {
super(new ConcurrentHashMap(), collection);
}
/**
* {@inheritDoc}
*/
@Override
public boolean add(E element) {
Boolean answer = ((ConcurrentMap) map).putIfAbsent(element, Boolean.TRUE);
return answer == null;
}
}