1 files changed, 278 insertions, 0 deletions
diff --git a/model/basic-model/src/main/java/org/onap/apex/model/basicmodel/handling/ApexModelWriter.java b/model/basic-model/src/main/java/org/onap/apex/model/basicmodel/handling/ApexModelWriter.java
new file mode 100644
index 000000000..5b7a9568b
--- /dev/null
+++ b/model/basic-model/src/main/java/org/onap/apex/model/basicmodel/handling/ApexModelWriter.java
@@ -0,0 +1,278 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * 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.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.apex.model.basicmodel.handling;
+
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.io.Writer;
+import java.util.Set;
+import java.util.TreeSet;
+
+import javax.xml.bind.JAXBContext;
+import javax.xml.bind.JAXBException;
+import javax.xml.bind.Marshaller;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
+import javax.xml.transform.OutputKeys;
+import javax.xml.transform.Transformer;
+import javax.xml.transform.TransformerException;
+import javax.xml.transform.TransformerFactory;
+import javax.xml.transform.dom.DOMSource;
+import javax.xml.transform.stream.StreamResult;
+
+import org.eclipse.persistence.jaxb.JAXBContextFactory;
+import org.eclipse.persistence.jaxb.MarshallerProperties;
+import org.eclipse.persistence.oxm.MediaType;
+import org.onap.apex.model.basicmodel.concepts.AxConcept;
+import org.onap.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.utilities.Assertions;
+import org.slf4j.ext.XLogger;
+import org.slf4j.ext.XLoggerFactory;
+import org.w3c.dom.Document;
+
+/**
+ * This class writes an Apex concept to an XML file or JSON file from a Java Apex Concept.
+ *
+ * @author John Keeney (john.keeney@ericsson.com)
+ * @param <C> the type of Apex concept to write, must be a sub class of {@link AxConcept}
+ */
+public class ApexModelWriter<C extends AxConcept> {
+	private static final String CONCEPT_MAY_NOT_BE_NULL = "concept may not be null";
+    private static final String CONCEPT_WRITER_MAY_NOT_BE_NULL = "concept writer may not be null";
+	private static final String CONCEPT_STREAM_MAY_NOT_BE_NULL = "concept stream may not be null";
+
+	// Get a reference to the logger
+    private static final XLogger LOGGER = XLoggerFactory.getXLogger(ApexModelWriter.class);
+
+    // Writing as JSON or XML
+    private boolean jsonOutput = false;
+
+    // The list of fields to output as CDATA
+    private final Set<String> cDataFieldSet = new TreeSet<>();
+
+    // The Marshaller for the Apex concepts
+    private Marshaller marshaller = null;
+
+    // All written concepts are validated before writing if this flag is set
+    private boolean validateFlag = true;
+
+    /**
+     * Constructor, initiates the writer.
+     *
+     * @param rootConceptClass the root concept class for concept reading
+     * @throws ApexModelException the apex concept writer exception
+     */
+    public ApexModelWriter(final Class<C> rootConceptClass) throws ApexModelException {
+        // Set up Eclipselink for XML and JSON output
+        System.setProperty("javax.xml.bind.context.factory", "org.eclipse.persistence.jaxb.JAXBContextFactory");
+
+        try {
+            final JAXBContext jaxbContext = JAXBContextFactory.createContext(new Class[] {rootConceptClass}, null);
+
+            // Set up the unmarshaller to carry out validation
+            marshaller = jaxbContext.createMarshaller();
+            marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
+            marshaller.setEventHandler(new javax.xml.bind.helpers.DefaultValidationEventHandler());
+        }
+        catch (final JAXBException e) {
+            LOGGER.error("JAXB marshaller creation exception", e);
+            throw new ApexModelException("JAXB marshaller creation exception", e);
+        }
+    }
+
+    /**
+     * The set of fields to be output as CDATA.
+     *
+     * @return the set of fields
+     */
+    public Set<String> getCDataFieldSet() {
+        return cDataFieldSet;
+    }
+
+    /**
+     * Return true if JSON output enabled, XML output if false.
+     *
+     * @return true for JSON output
+     */
+    public boolean isJsonOutput() {
+        return jsonOutput;
+    }
+
+    /**
+     * Set the value of JSON output, true for JSON output, false for XML output.
+     *
+     * @param jsonOutput true for JSON output
+     * @throws ApexModelException on errors setting output type
+     */
+    public void setJsonOutput(final boolean jsonOutput) throws ApexModelException {
+        this.jsonOutput = jsonOutput;
+
+        // Set up output specific parameters
+        if (this.jsonOutput) {
+            try {
+                marshaller.setProperty(MarshallerProperties.MEDIA_TYPE, MediaType.APPLICATION_JSON);
+                marshaller.setProperty(MarshallerProperties.JSON_INCLUDE_ROOT, true);
+            }
+            catch (final Exception e) {
+                LOGGER.warn("JAXB error setting marshaller for JSON output", e);
+                throw new ApexModelException("JAXB error setting marshaller for JSON output", e);
+            }
+        }
+        else {
+            try {
+                marshaller.setProperty(MarshallerProperties.MEDIA_TYPE, MediaType.APPLICATION_XML);
+            }
+            catch (final Exception e) {
+                LOGGER.warn("JAXB error setting marshaller for XML output", e);
+                throw new ApexModelException("JAXB error setting marshaller for XML output", e);
+            }
+        }
+    }
+
+    /**
+     * This method validates the Apex concept then writes it into a stream.
+     *
+     * @param concept the concept to write
+     * @param apexConceptStream the stream to write to
+     * @throws ApexModelException on validation or writing exceptions
+     */
+    public void write(final C concept, final OutputStream apexConceptStream) throws ApexModelException {
+        Assertions.argumentNotNull(concept, CONCEPT_MAY_NOT_BE_NULL);
+        Assertions.argumentNotNull(apexConceptStream, CONCEPT_STREAM_MAY_NOT_BE_NULL);
+        
+        this.write(concept, new OutputStreamWriter(apexConceptStream));
+    }
+
+    /**
+     * This method validates the Apex concept then writes it into a writer.
+     *
+     * @param concept the concept to write
+     * @param apexConceptWriter the writer to write to
+     * @throws ApexModelException on validation or writing exceptions
+     */
+    public void write(final C concept, final Writer apexConceptWriter) throws ApexModelException {
+        Assertions.argumentNotNull(concept, CONCEPT_MAY_NOT_BE_NULL);
+        Assertions.argumentNotNull(apexConceptWriter, CONCEPT_WRITER_MAY_NOT_BE_NULL);
+
+        // Check if we should validate the concept
+        if (validateFlag) {
+            // Validate the concept first
+            final AxValidationResult validationResult = concept.validate(new AxValidationResult());
+            LOGGER.debug(validationResult.toString());
+            if (!validationResult.isValid()) {
+                LOGGER.warn(validationResult.toString());
+                throw new ApexModelException("Apex concept xml (" + concept.getKey().getID() + ") validation failed");
+            }
+        }
+
+        if (jsonOutput) {
+            writeJSON(concept, apexConceptWriter);
+        }
+        else {
+            writeXML(concept, apexConceptWriter);
+        }
+    }
+
+    /**
+     * This method writes the Apex concept into a writer in XML format.
+     *
+     * @param concept the concept to write
+     * @param apexConceptWriter the writer to write to
+     * @throws ApexModelException on validation or writing exceptions
+     */
+    private void writeXML(final C concept, final Writer apexConceptWriter) throws ApexModelException {
+        Assertions.argumentNotNull(concept, CONCEPT_MAY_NOT_BE_NULL);
+
+        LOGGER.debug("writing Apex concept XML . . .");
+
+        try {
+            // Write the concept into a DOM document, then transform to add CDATA fields and pretty print, then write out the result
+            final DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
+            final Document document = docBuilderFactory.newDocumentBuilder().newDocument();
+
+            // Marshal the concept into the empty document.
+            marshaller.marshal(concept, document);
+
+            // Transform the DOM to the output stream
+            final TransformerFactory transformerFactory = TransformerFactory.newInstance();
+            final Transformer domTransformer = transformerFactory.newTransformer();
+
+            // Pretty print
+            try {
+                domTransformer.setOutputProperty(OutputKeys.INDENT, "yes");
+                // May fail if not using XALAN XSLT engine. But not in any way vital
+                domTransformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2");
+            }
+            catch (final Exception ignore) {
+            		// We ignore exceptions here and catch errors below
+            }
+
+            // Convert the cDataFieldSet into a space delimited string
+            domTransformer.setOutputProperty(OutputKeys.CDATA_SECTION_ELEMENTS, cDataFieldSet.toString().replaceAll("[\\[\\]\\,]", " "));
+            domTransformer.transform(new DOMSource(document), new StreamResult(apexConceptWriter));
+        }
+        catch (JAXBException | TransformerException | ParserConfigurationException e) {
+            LOGGER.warn("Unable to marshal Apex concept XML", e);
+            throw new ApexModelException("Unable to marshal Apex concept XML", e);
+        }
+        LOGGER.debug("wrote Apex concept XML");
+    }
+
+    /**
+     * This method writes the Apex concept into a writer in JSON format.
+     *
+     * @param concept the concept to write
+     * @param apexConceptWriter the writer to write to
+     * @throws ApexModelException on validation or writing exceptions
+     */
+    private void writeJSON(final C concept, final Writer apexConceptWriter) throws ApexModelException {
+        Assertions.argumentNotNull(concept, CONCEPT_MAY_NOT_BE_NULL);
+
+        LOGGER.debug("writing Apex concept JSON . . .");
+
+        try {
+            marshaller.marshal(concept, apexConceptWriter);
+        }
+        catch (final JAXBException e) {
+            LOGGER.warn("Unable to marshal Apex concept JSON", e);
+            throw new ApexModelException("Unable to marshal Apex concept JSON", e);
+        }
+        LOGGER.debug("wrote Apex concept JSON");
+    }
+
+    /**
+     * Gets the validation flag value.
+     *
+     * @return the validation flag value
+     */
+    public boolean getValidateFlag() {
+        return validateFlag;
+    }
+
+    /**
+     * Sets the validation flag.
+     *
+     * @param validateFlag the validation flag value
+     */
+    public void setValidateFlag(final boolean validateFlag) {
+        this.validateFlag = validateFlag;
+    }
+}