FixedTransformProvider.java
/* Copyright 2002-2024 CS GROUP
* Licensed to CS GROUP (CS) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* CS 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.orekit.frames;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
import org.hipparchus.CalculusFieldElement;
import org.hipparchus.Field;
import org.orekit.time.AbsoluteDate;
import org.orekit.time.FieldAbsoluteDate;
/**
** Transform provider using fixed transform.
* @author Luc Maisonobe
*/
public class FixedTransformProvider implements TransformProvider {
/** Serializable UID. */
private static final long serialVersionUID = 20170106L;
/** Fixed transform. */
private final Transform transform;
/** Cached field-based transforms. */
private final transient Map<Field<? extends CalculusFieldElement<?>>, FieldTransform<? extends CalculusFieldElement<?>>> cached;
/** Simple constructor.
* @param transform fixed transform
*/
public FixedTransformProvider(final Transform transform) {
this.transform = transform;
this.cached = new HashMap<>();
}
/** {@inheritDoc} */
public Transform getTransform(final AbsoluteDate date) {
return transform;
}
/** {@inheritDoc} */
@SuppressWarnings("unchecked")
@Override
public <T extends CalculusFieldElement<T>> FieldTransform<T> getTransform(final FieldAbsoluteDate<T> date) {
synchronized (cached) {
return (FieldTransform<T>) cached.computeIfAbsent(date.getField(),
f -> new FieldTransform<>((Field<T>) f, transform));
}
}
/** Replace the instance with a data transfer object for serialization.
* <p>
* This intermediate class serializes nothing.
* </p>
* @return data transfer object that will be serialized
*/
private Object writeReplace() {
return new DataTransferObject(transform);
}
/** Internal class used only for serialization. */
private static class DataTransferObject implements Serializable {
/** Serializable UID. */
private static final long serialVersionUID = 20170106L;
/** Fixed transform. */
private final Transform transform;
/** Simple constructor.
* @param transform fixed transform
*/
private DataTransferObject(final Transform transform) {
this.transform = transform;
}
/** Replace the deserialized data transfer object with a {@link FixedTransformProvider}.
* @return replacement {@link FixedTransformProvider}
*/
private Object readResolve() {
return new FixedTransformProvider(transform);
}
}
}