kieker.common.namedRecordPipe.Broker Maven / Gradle / Ivy
/***************************************************************************
* Copyright 2013 Kieker Project (http://kieker-monitoring.net)
*
* Licensed 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 kieker.common.namedRecordPipe;
import java.util.concurrent.ConcurrentHashMap;
/**
*
* @author Andre van Hoorn, Jan Waller
*
* @since 1.3
*/
public enum Broker { // Singleton pattern (Effective Java #3)
/** This is the singleton instance. */
INSTANCE;
/**
* Access synchronized through synchronized method {@link #acquirePipe(String)} !
*/
private final transient ConcurrentHashMap pipeMap = new ConcurrentHashMap();
/**
* Returns a connection with name {@code pipeName}. If a connection with this
* name does not exist prior to the call, it is created.
*
* @param pipeName
* The name of the pipe.
*
* @return The acquired pipe.
*
* @throws IllegalArgumentException
* If the pipe name is null or empty.
*/
public Pipe acquirePipe(final String pipeName) throws IllegalArgumentException {
Pipe conn;
synchronized (this) {
if ((pipeName == null) || (pipeName.length() == 0)) {
// LOG.error(errorMsg); no need to log if thrown
throw new IllegalArgumentException("pipeName must not be null or empty! (Found: " + pipeName + ")");
}
final Pipe newPipe = new Pipe(pipeName);
conn = this.pipeMap.putIfAbsent(pipeName, newPipe);
if (conn == null) {
return newPipe;
} else {
return conn;
}
}
}
}