Java tutorial
/** * Copyright (c) 2015 Source Auditor Inc. * * Licensed 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.spdx.rdfparser.model; import java.util.Map; import org.spdx.rdfparser.IModelContainer; import org.spdx.rdfparser.InvalidSPDXAnalysisException; import org.spdx.rdfparser.SpdxDocumentContainer; import org.spdx.rdfparser.SpdxRdfConstants; import com.google.common.collect.Maps; import org.apache.jena.graph.Node; import org.apache.jena.graph.Triple; import org.apache.jena.util.iterator.ExtendedIterator; /** * Factory for creating SpdxElements from a Jena Model * @author Gary O'Neall * */ public class SpdxElementFactory { /** * Add to a cache of created elements * @param modelContainer * @param node * @param element */ static synchronized void addToCreatedElements(IModelContainer modelContainer, Node node, SpdxElement element) { Map<Node, SpdxElement> containerNodes = createdElements.get(modelContainer); if (containerNodes == null) { containerNodes = Maps.newHashMap(); createdElements.put(modelContainer, containerNodes); } containerNodes.put(node, element); } /** * Keep track of all nodes created both for performance and to prevent * an infinite recursion from continually creating the same objects. */ private static Map<IModelContainer, Map<Node, SpdxElement>> createdElements = Maps.newHashMap(); public static synchronized SpdxElement createElementFromModel(IModelContainer modelContainer, Node node) throws InvalidSPDXAnalysisException { Map<Node, SpdxElement> containerNodes = createdElements.get(modelContainer); if (containerNodes == null) { containerNodes = Maps.newHashMap(); createdElements.put(modelContainer, containerNodes); } SpdxElement retval = containerNodes.get(node); if (retval != null) { return retval; } if (!node.isURI() && !node.isBlank()) { throw (new InvalidSPDXAnalysisException("Can not create an SPDX Element from a literal node")); } if (node.isURI() && !node.getURI().startsWith(modelContainer.getDocumentNamespace())) { // assume this is an external document reference String[] uriParts = node.getURI().split("#"); if (uriParts.length != 2) { throw (new InvalidSPDXAnalysisException("Invalid element URI: " + node.getURI())); } String docId = modelContainer.documentNamespaceToId(uriParts[0]); if (docId == null) { throw (new InvalidSPDXAnalysisException( "No external document reference was found for URI " + node.getURI())); } String externalId = docId + ":" + uriParts[1]; return new ExternalSpdxElement(externalId); } retval = getElementByType(modelContainer, node); if (retval == null) { retval = guessElementByProperties(modelContainer, node); if (retval == null) { throw (new InvalidSPDXAnalysisException( "Unable to determine the SPDX element type from the model")); } } containerNodes.put(node, retval); return retval; } /** * Guesses the element type based on the properties associated with that element. * @param modelContainer * @param node * @return * @throws InvalidSPDXAnalysisException */ private static SpdxElement guessElementByProperties(IModelContainer modelContainer, Node node) throws InvalidSPDXAnalysisException { // Look for required SPDX Item properties if (propertyExists(modelContainer, node, SpdxRdfConstants.SPDX_NAMESPACE, SpdxRdfConstants.PROP_LICENSE_CONCLUDED) && propertyExists(modelContainer, node, SpdxRdfConstants.SPDX_NAMESPACE, SpdxRdfConstants.PROP_COPYRIGHT_TEXT)) { return guessSpdxItemByProperties(modelContainer, node); } else { return new SpdxElement(modelContainer, node); } } /** * Guess an SPDX Item based on the properties * @param modelContainer * @param node * @return * @throws InvalidSPDXAnalysisException */ private static SpdxElement guessSpdxItemByProperties(IModelContainer modelContainer, Node node) throws InvalidSPDXAnalysisException { // Look for required file properties if (propertyExists(modelContainer, node, SpdxRdfConstants.SPDX_NAMESPACE, SpdxRdfConstants.PROP_FILE_CHECKSUM) && propertyExists(modelContainer, node, SpdxRdfConstants.SPDX_NAMESPACE, SpdxRdfConstants.PROP_FILE_TYPE)) { return new SpdxFile(modelContainer, node); } else if (propertyExists(modelContainer, node, SpdxRdfConstants.SPDX_NAMESPACE, SpdxRdfConstants.PROP_FILE_CHECKSUM) && propertyExists(modelContainer, node, SpdxRdfConstants.SPDX_NAMESPACE, SpdxRdfConstants.PROP_PACKAGE_DOWNLOAD_URL) && propertyExists(modelContainer, node, SpdxRdfConstants.SPDX_NAMESPACE, SpdxRdfConstants.PROP_PACKAGE_LICENSE_INFO_FROM_FILES) && propertyExists(modelContainer, node, SpdxRdfConstants.SPDX_NAMESPACE, SpdxRdfConstants.PROP_PACKAGE_VERIFICATION_CODE)) { return new SpdxPackage(modelContainer, node); } else if (propertyExists(modelContainer, node, SpdxRdfConstants.SPDX_NAMESPACE, SpdxRdfConstants.PROP_SNIPPET_FROM_FILE)) { return new SpdxSnippet(modelContainer, node); } else { return new SpdxItem(modelContainer, node); } } /** * Returns true if a value for a property exists for the subject node * @param modelContainer * @param node * @param namespace * @param propertyName * @return */ private static boolean propertyExists(IModelContainer modelContainer, Node node, String namespace, String propertyName) { Node p = modelContainer.getModel().getProperty(namespace, propertyName).asNode(); Triple m = Triple.createMatch(node, p, null); ExtendedIterator<Triple> tripleIter = modelContainer.getModel().getGraph().find(m); return tripleIter.hasNext(); } /** * @param modelContainer * @param node * @return * @throws InvalidSPDXAnalysisException */ private static SpdxElement getElementByType(IModelContainer modelContainer, Node node) throws InvalidSPDXAnalysisException { Node rdfTypePredicate = modelContainer.getModel() .getProperty(SpdxRdfConstants.RDF_NAMESPACE, SpdxRdfConstants.RDF_PROP_TYPE).asNode(); Triple m = Triple.createMatch(node, rdfTypePredicate, null); ExtendedIterator<Triple> tripleIter = modelContainer.getModel().getGraph().find(m); // find the type(s) if (tripleIter.hasNext()) { Triple triple = tripleIter.next(); if (tripleIter.hasNext()) { throw (new InvalidSPDXAnalysisException("More than one type associated with an SPDX Element")); } Node typeNode = triple.getObject(); if (!typeNode.isURI()) { throw (new InvalidSPDXAnalysisException("Invalid type for an SPDX Element - not a URI")); } // need to parse the URI String typeUri = typeNode.getURI(); if (!typeUri.startsWith(SpdxRdfConstants.SPDX_NAMESPACE)) { throw (new InvalidSPDXAnalysisException("Invalid type for an SPDX Element - not an SPDX type")); } String type = typeUri.substring(SpdxRdfConstants.SPDX_NAMESPACE.length()); if (type.equals(SpdxRdfConstants.CLASS_SPDX_FILE)) { return new SpdxFile(modelContainer, node); } else if (type.equals(SpdxRdfConstants.CLASS_SPDX_PACKAGE)) { return new SpdxPackage(modelContainer, node); } else if (type.equals(SpdxRdfConstants.CLASS_SPDX_SNIPPET)) { return new SpdxSnippet(modelContainer, node); } else if (type.equals(SpdxRdfConstants.CLASS_SPDX_ITEM)) { return new SpdxItem(modelContainer, node); } else if (type.equals(SpdxRdfConstants.CLASS_SPDX_ELEMENT)) { return new SpdxElement(modelContainer, node); } else if (type.equals(SpdxRdfConstants.CLASS_SPDX_DOCUMENT)) { return new SpdxDocumentContainer(modelContainer.getModel()).getSpdxDocument(); } else { throw (new InvalidSPDXAnalysisException("Invalid type for element '" + type + "'")); } } else { return null; } } }