1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
|
/*-
* ============LICENSE_START=======================================================
* Copyright (C) 2019 Nordix Foundation.
* ================================================================================
* 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.models.base;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import javax.ws.rs.core.Response;
import lombok.NonNull;
/**
* The model service makes Policy Framework models available to all classes in a JVM.
*
* <p>The reason for having a model service is to avoid having to pass concept and model definitions down long call
* chains in modules such as the Policy Framework engine and editor. The model service makes the model and concept
* definitions available statically.
*
* <p>Note that the use of the model service means that only a single Policy Framework model of a particular type may
* exist in Policy Framework (particularly the engine) at any time. Of course the model in a JVM can be changed at any
* time provided all users of the model are stopped and restarted in an orderly manner.
*/
public abstract class PfModelService {
// The map holding the models
private static Map<String, PfConcept> modelMap = new ConcurrentHashMap<>();
/**
* This class is an abstract static class that cannot be extended.
*/
private PfModelService() {
// Default constructor
}
/**
* Register a model with the model service.
*
* @param <M> the generic type
* @param modelKey the key of the model, used to index the model
* @param model The model
*/
public static <M extends PfConcept> void registerModel(@NonNull final String modelKey, @NonNull final M model) {
modelMap.put(modelKey, model);
}
/**
* Remove a model from the model service.
*
* @param modelKey the key of the model, used to index the model
*/
public static void deregisterModel(@NonNull final String modelKey) {
modelMap.remove(modelKey);
}
/**
* Get a model from the model service.
*
* @param <M> the generic type
* @param modelKey the key of the model, used to index the model
* @return The model
*/
@SuppressWarnings("unchecked")
public static <M extends PfConcept> M getModel(@NonNull final String modelKey) {
final M model = (M) modelMap.get(modelKey);
if (model == null) {
throw new PfModelRuntimeException(Response.Status.INTERNAL_SERVER_ERROR,
"Model for name " + modelKey + " not found in model service");
}
return model;
}
/**
* Check if a model is defined on the model service.
*
* @param modelKey the key of the model, used to index the model
* @return true if the model is defined
*/
public static boolean existsModel(final String modelKey) {
return modelMap.get(modelKey) != null;
}
/**
* Clear all models in the model service.
*/
public static void clear() {
modelMap.clear();
}
}
|