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Diffstat (limited to 'src/main/java/org/apache/commons/math/ode/sampling/DummyStepHandler.java')
-rw-r--r-- | src/main/java/org/apache/commons/math/ode/sampling/DummyStepHandler.java | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/src/main/java/org/apache/commons/math/ode/sampling/DummyStepHandler.java b/src/main/java/org/apache/commons/math/ode/sampling/DummyStepHandler.java new file mode 100644 index 0000000..cc759b9 --- /dev/null +++ b/src/main/java/org/apache/commons/math/ode/sampling/DummyStepHandler.java @@ -0,0 +1,101 @@ +/* + * 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; + } + +} |