| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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. |
| */ |
| |
| package org.apache.commons.math.ode.sampling; |
| |
| /** |
| * This class is a step handler that does nothing. |
| |
| * <p>This class is provided as a convenience for users who are only |
| * interested in the final state of an integration and not in the |
| * intermediate steps. Its handleStep method does nothing.</p> |
| * |
| * <p>Since this class has no internal state, it is implemented using |
| * the Singleton design pattern. This means that only one instance is |
| * ever created, which can be retrieved using the getInstance |
| * method. This explains why there is no public constructor.</p> |
| * |
| * @see StepHandler |
| * @version $Revision: 811827 $ $Date: 2009-09-06 17:32:50 +0200 (dim. 06 sept. 2009) $ |
| * @since 1.2 |
| */ |
| |
| public class DummyStepHandler implements StepHandler { |
| |
| /** Private constructor. |
| * The constructor is private to prevent users from creating |
| * instances (Singleton design-pattern). |
| */ |
| private DummyStepHandler() { |
| } |
| |
| /** Get the only instance. |
| * @return the only instance |
| */ |
| public static DummyStepHandler getInstance() { |
| return LazyHolder.INSTANCE; |
| } |
| |
| /** Determines whether this handler needs dense output. |
| * Since this handler does nothing, it does not require dense output. |
| * @return always false |
| */ |
| public boolean requiresDenseOutput() { |
| return false; |
| } |
| |
| /** Reset the step handler. |
| * Initialize the internal data as required before the first step is |
| * handled. |
| */ |
| public void reset() { |
| } |
| |
| /** |
| * Handle the last accepted step. |
| * This method does nothing in this class. |
| * @param interpolator interpolator for the last accepted step. For |
| * efficiency purposes, the various integrators reuse the same |
| * object on each call, so if the instance wants to keep it across |
| * all calls (for example to provide at the end of the integration a |
| * continuous model valid throughout the integration range), it |
| * should build a local copy using the clone method and store this |
| * copy. |
| * @param isLast true if the step is the last one |
| */ |
| public void handleStep(final StepInterpolator interpolator, final boolean isLast) { |
| } |
| |
| // CHECKSTYLE: stop HideUtilityClassConstructor |
| /** Holder for the instance. |
| * <p>We use here the Initialization On Demand Holder Idiom.</p> |
| */ |
| private static class LazyHolder { |
| /** Cached field instance. */ |
| private static final DummyStepHandler INSTANCE = new DummyStepHandler(); |
| } |
| // CHECKSTYLE: resume HideUtilityClassConstructor |
| |
| /** Handle deserialization of the singleton. |
| * @return the singleton instance |
| */ |
| private Object readResolve() { |
| // return the singleton instance |
| return LazyHolder.INSTANCE; |
| } |
| |
| } |