2 * ============LICENSE_START=======================================================
3 * Copyright (C) 2019 Nordix Foundation.
4 * ================================================================================
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
9 * http://www.apache.org/licenses/LICENSE-2.0
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
17 * SPDX-License-Identifier: Apache-2.0
18 * ============LICENSE_END=========================================================
21 package org.onap.policy.models.base;
24 import java.util.concurrent.ConcurrentHashMap;
26 import javax.ws.rs.core.Response;
28 import lombok.NonNull;
31 * The model service makes Policy Framework models available to all classes in a JVM.
33 * <p>The reason for having a model service is to avoid having to pass concept and model definitions down long call
34 * chains in modules such as the Policy Framework engine and editor. The model service makes the model and concept
35 * definitions available statically.
37 * <p>Note that the use of the model service means that only a single Policy Framework model of a particular type may
38 * exist in Policy Framework (particularly the engine) at any time. Of course the model in a JVM can be changed at any
39 * time provided all users of the model are stopped and restarted in an orderly manner.
41 public abstract class PfModelService {
42 // The map holding the models
43 private static Map<String, PfConcept> modelMap = new ConcurrentHashMap<>();
46 * This class is an abstract static class that cannot be extended.
48 private PfModelService() {
49 // Default constructor
53 * Register a model with the model service.
55 * @param <M> the generic type
56 * @param modelKey the key of the model, used to index the model
57 * @param model The model
59 public static <M extends PfConcept> void registerModel(@NonNull final String modelKey, @NonNull final M model) {
60 modelMap.put(modelKey, model);
64 * Remove a model from the model service.
66 * @param modelKey the key of the model, used to index the model
68 public static void deregisterModel(@NonNull final String modelKey) {
69 modelMap.remove(modelKey);
73 * Get a model from the model service.
75 * @param <M> the generic type
76 * @param modelKey the key of the model, used to index the model
79 @SuppressWarnings("unchecked")
80 public static <M extends PfConcept> M getModel(@NonNull final String modelKey) {
81 final M model = (M) modelMap.get(modelKey);
84 throw new PfModelRuntimeException(Response.Status.INTERNAL_SERVER_ERROR,
85 "Model for name " + modelKey + " not found in model service");
92 * Check if a model is defined on the model service.
94 * @param modelKey the key of the model, used to index the model
95 * @return true if the model is defined
97 public static boolean existsModel(final String modelKey) {
98 return modelMap.get(modelKey) != null;
102 * Clear all models in the model service.
104 public static void clear() {