/*******************************************************************************
* This file is part of OpenNMS(R).
*
* Copyright (C) 2011 The OpenNMS Group, Inc.
* OpenNMS(R) is Copyright (C) 1999-2011 The OpenNMS Group, Inc.
*
* OpenNMS(R) is a registered trademark of The OpenNMS Group, Inc.
*
* OpenNMS(R) is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published
* by the Free Software Foundation, either version 3 of the License,
* or (at your option) any later version.
*
* OpenNMS(R) is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with OpenNMS(R). If not, see:
* http://www.gnu.org/licenses/
*
* For more information contact:
* OpenNMS(R) Licensing <license@opennms.org>
* http://www.opennms.org/
* http://www.opennms.com/
*******************************************************************************/
package org.opennms.serviceregistration;
public class ServiceRegistrationFactory {
private static ServiceRegistrationStrategy s;
private static final String CLASS_PROPERTY = "org.opennms.serviceregistration.strategy";
private static final String[] classes = {
"org.opennms.serviceregistration.strategies.AppleStrategy",
"org.opennms.serviceregistration.strategies.JMDNSStrategy",
"org.opennms.serviceregistration.strategies.NullStrategy"
};
private ServiceRegistrationFactory() {
}
public static synchronized ServiceRegistrationStrategy getStrategy() throws Exception {
if (s == null) {
if (System.getProperty(CLASS_PROPERTY) != null) {
try {
s = (ServiceRegistrationStrategy)(Class.forName(System.getProperty(CLASS_PROPERTY)).newInstance());
} catch (NoClassDefFoundError e) {
System.err.println("unable to load class specified in " + CLASS_PROPERTY + ": " + e.getMessage());
}
}
if (s == null) {
for (String className : classes) {
try {
s = (ServiceRegistrationStrategy)(Class.forName(className).newInstance());
} catch (NoClassDefFoundError e) {
// fall through silently for now
} catch (UnsatisfiedLinkError e) {
// fall through silently for now
}
if (s != null) {
break;
}
}
}
}
if (s == null) {
System.err.println("an error occurred finding any service registration strategy");
}
return s;
}
public Object clone() throws CloneNotSupportedException {
throw new CloneNotSupportedException("Singletons cannot be cloned.");
}
}