Java tutorial
/* * 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.jena.geosparql.implementation.registry; import java.lang.invoke.MethodHandles; import org.apache.commons.collections4.keyvalue.MultiKey; import org.apache.commons.collections4.map.HashedMap; import org.apache.commons.collections4.map.MultiKeyMap; import org.apache.sis.referencing.CRS; import org.opengis.geometry.MismatchedDimensionException; import org.opengis.referencing.crs.CoordinateReferenceSystem; import org.opengis.referencing.operation.MathTransform; import org.opengis.referencing.operation.TransformException; import org.opengis.util.FactoryException; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * * */ public class MathTransformRegistry { private static final Logger LOGGER = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass()); private static final MultiKeyMap<CoordinateReferenceSystem, MathTransform> MATH_TRANSFORM_REGISTRY = MultiKeyMap .multiKeyMap(new HashedMap<>()); public synchronized static final MathTransform getMathTransform(CoordinateReferenceSystem sourceCRS, CoordinateReferenceSystem targetCRS) throws FactoryException, MismatchedDimensionException, TransformException { MathTransform transform; MultiKey<CoordinateReferenceSystem> key = new MultiKey<>(sourceCRS, targetCRS); if (MATH_TRANSFORM_REGISTRY.containsKey(key)) { transform = MATH_TRANSFORM_REGISTRY.get(key); } else { transform = CRS.findOperation(sourceCRS, targetCRS, null).getMathTransform(); MATH_TRANSFORM_REGISTRY.put(key, transform); } return transform; } public synchronized static final void clear() { MATH_TRANSFORM_REGISTRY.clear(); } }