001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.camel.spi;
018
019 /**
020 * A service pool is like a connection pool but can pool any kind of objects.
021 * <p/>
022 * Services that is capable of being pooled should implement the marker interface
023 * {@link org.apache.camel.ServicePoolAware}.
024 *
025 * @version $Revision: 779038 $
026 */
027 public interface ServicePool<Key, Service> extends org.apache.camel.Service {
028
029 /**
030 * Adds the given service to the pool and acquires it.
031 *
032 * @param key the key
033 * @param service the service
034 * @return the acquired service, is newer <tt>null</tt>
035 */
036 Service addAndAcquire(Key key, Service service);
037
038 /**
039 * Tries to acquire the servie with the given key
040 *
041 * @param key the key
042 * @return the acquired service, or <tt>null</tt> if no free in pool
043 */
044 Service acquire(Key key);
045
046 /**
047 * Releases the service back to the pool
048 *
049 * @param key the key
050 * @param service the service
051 */
052 void release(Key key, Service service);
053
054 }