/*-
* ============LICENSE_START=======================================================
* Copyright (C) 2018 Ericsson. All rights reserved.
* ================================================================================
* 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.
*
* SPDX-License-Identifier: Apache-2.0
* ============LICENSE_END=========================================================
*/
package org.onap.policy.common.parameters;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
/**
* The parameter service makes ONAP PF parameter groups available to all classes in a JVM.
*
*
The reason for having a parameter service is to avoid having to pass parameters down long call chains in modules
* such as PDPs and editors. The parameter service makes correct and verified parameters available statically.
*
*
The parameter service must be used with care because changing a parameter set anywhere in a JVM will affect all
* users of those parameters anywhere in the JVM.
*
* @author Liam Fallon (liam.fallon@ericsson.com)
*/
public abstract class ParameterService {
// The map holding the parameters
private static Map parameterGroupMap = new ConcurrentHashMap<>();
/**
* This class is an abstract static class that cannot be extended.
*/
private ParameterService() {
}
/**
* Register a parameter group with the parameter service.
*
* @param parameterGroup the parameter group
*/
public static void register(final ParameterGroup parameterGroup) {
if (!parameterGroupMap.containsKey(parameterGroup.getName())) {
parameterGroupMap.put(parameterGroup.getName(), parameterGroup);
} else {
throw new ParameterRuntimeException(
"\"" + parameterGroup.getName() + "\" already registered in parameter service");
}
}
/**
* Register a parameter group with the parameter service.
*
* @param parameterGroup the parameter group
* @param overwrite if true, overwrite the current value if set
*/
public static void register(final ParameterGroup parameterGroup, final boolean overwrite) {
if (overwrite && parameterGroupMap.containsKey(parameterGroup.getName())) {
deregister(parameterGroup);
}
register(parameterGroup);
}
/**
* Remove a parameter group from the parameter service.
*
* @param parameterGroupName the name of the parameter group
*/
public static void deregister(final String parameterGroupName) {
if (parameterGroupMap.containsKey(parameterGroupName)) {
parameterGroupMap.remove(parameterGroupName);
} else {
throw new ParameterRuntimeException("\"" + parameterGroupName + "\" not registered in parameter service");
}
}
/**
* Remove a parameter group from the parameter service.
*
* @param parameterGroup the parameter group
*/
public static void deregister(final ParameterGroup parameterGroup) {
deregister(parameterGroup.getName());
}
/**
* Get a parameter group from the parameter service.
*
* @param parameterGroupName the name of the parameter group
* @return The parameter group
*/
public static T get(final String parameterGroupName) {
@SuppressWarnings("unchecked")
final T parameterGroup = (T) parameterGroupMap.get(parameterGroupName);
if (parameterGroup == null) {
throw new ParameterRuntimeException("\"" + parameterGroupName + "\" not found in parameter service");
}
return parameterGroup;
}
/**
* Check if a parameter group is defined on the parameter service.
*
* @param parameterGroupName the name of the parameter group
* @return true if the parameter is defined
*/
public static boolean contains(final String parameterGroupName) {
return parameterGroupMap.containsKey(parameterGroupName) && parameterGroupMap.get(parameterGroupName) != null;
}
/**
* Get all parameter groups.
*
* @return The entries
*/
public static Set> getAll() {
return parameterGroupMap.entrySet();
}
/**
* Clear all parameter groups in the parameter service.
*/
public static void clear() {
parameterGroupMap.clear();
}
}