1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * https://www.apache.org/licenses/LICENSE-2.0
10 *
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.
16 */
17
18 /*
19 * This is not the original file distributed by the Apache Software Foundation
20 * It has been modified by the Hipparchus project
21 */
22
23 package org.hipparchus.migration.ode.sampling;
24
25 import org.hipparchus.ode.sampling.ODEStateInterpolator;
26 import org.hipparchus.ode.sampling.ODEStepHandler;
27
28 /**
29 * This class is a step handler that does nothing.
30
31 * <p>This class is provided as a convenience for users who are only
32 * interested in the final state of an integration and not in the
33 * intermediate steps. Its handleStep method does nothing.</p>
34 *
35 * <p>Since this class has no internal state, it is implemented using
36 * the Singleton design pattern. This means that only one instance is
37 * ever created, which can be retrieved using the getInstance
38 * method. This explains why there is no public constructor.</p>
39 *
40 * @deprecated as of 1.0, this class is not used anymore
41 */
42 @Deprecated
43 public class DummyStepHandler implements ODEStepHandler {
44
45 /** Private constructor.
46 * The constructor is private to prevent users from creating
47 * instances (Singleton design-pattern).
48 */
49 private DummyStepHandler() {
50 }
51
52 /** Get the only instance.
53 * @return the only instance
54 */
55 public static DummyStepHandler getInstance() {
56 return LazyHolder.INSTANCE;
57 }
58
59 /** {@inheritDoc} */
60 @Override
61 public void handleStep(final ODEStateInterpolator interpolator) {
62 }
63
64 // CHECKSTYLE: stop HideUtilityClassConstructor
65 /** Holder for the instance.
66 * <p>We use here the Initialization On Demand Holder Idiom.</p>
67 */
68 private static class LazyHolder {
69 /** Cached field instance. */
70 private static final DummyStepHandler INSTANCE = new DummyStepHandler();
71 }
72 // CHECKSTYLE: resume HideUtilityClassConstructor
73
74 /** Handle deserialization of the singleton.
75 * @return the singleton instance
76 */
77 private Object readResolve() {
78 // return the singleton instance
79 return LazyHolder.INSTANCE;
80 }
81
82 }