restconf/restconf-nb-bierman02/src/main/java/org/opendaylight/netconf/sal/streams/listeners/AbstractNotificationsData.java

   1 /*
   2  * Copyright (c) 2016 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.netconf.sal.streams.listeners;
   9
  10 import java.io.ByteArrayOutputStream;
  11 import java.io.IOException;
  12 import java.nio.charset.StandardCharsets;
  13 import java.time.Instant;
  14 import java.time.OffsetDateTime;
  15 import java.time.ZoneId;
  16 import java.time.format.DateTimeFormatter;
  17 import javax.xml.stream.XMLOutputFactory;
  18 import javax.xml.stream.XMLStreamException;
  19 import javax.xml.stream.XMLStreamWriter;
  20 import javax.xml.transform.OutputKeys;
  21 import javax.xml.transform.Transformer;
  22 import javax.xml.transform.TransformerException;
  23 import javax.xml.transform.TransformerFactory;
  24 import javax.xml.transform.dom.DOMResult;
  25 import javax.xml.transform.dom.DOMSource;
  26 import javax.xml.transform.stream.StreamResult;
  27 import org.opendaylight.yangtools.util.xml.UntrustedXML;
  28 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  29 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeStreamWriter;
  30 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeWriter;
  31 import org.opendaylight.yangtools.yang.data.codec.xml.XMLStreamNormalizedNodeStreamWriter;
  32 import org.opendaylight.yangtools.yang.model.util.SchemaInferenceStack.Inference;
  33 import org.slf4j.Logger;
  34 import org.slf4j.LoggerFactory;
  35 import org.w3c.dom.Document;
  36 import org.w3c.dom.Element;
  37
  38 /**
  39  * Abstract class for processing and preparing data.
  40  *
  41  */
  42 abstract class AbstractNotificationsData {
  43     private static final Logger LOG = LoggerFactory.getLogger(AbstractNotificationsData.class);
  44     private static final TransformerFactory TF = TransformerFactory.newInstance();
  45     private static final XMLOutputFactory OF = XMLOutputFactory.newFactory();
  46
  47     /**
  48      * Formats data specified by RFC3339.
  49      *
  50      * @param now time stamp
  51      * @return Data specified by RFC3339.
  52      */
  53     protected static String toRFC3339(final Instant now) {
  54         return DateTimeFormatter.ISO_OFFSET_DATE_TIME.format(OffsetDateTime.ofInstant(now, ZoneId.systemDefault()));
  55     }
  56
  57     /**
  58      * Creates {@link Document} document.
  59      *
  60      * @return {@link Document} document.
  61      */
  62     protected static Document createDocument() {
  63         return UntrustedXML.newDocumentBuilder().newDocument();
  64     }
  65
  66     /**
  67      * Write normalized node to {@link DOMResult}.
  68      *
  69      * @param normalized
  70      *            data
  71      * @param inference
  72      *            SchemaInferenceStack state for the data
  73      * @return {@link DOMResult}
  74      */
  75     protected DOMResult writeNormalizedNode(final NormalizedNode normalized, final Inference inference)
  76             throws IOException, XMLStreamException {
  77         final Document doc = UntrustedXML.newDocumentBuilder().newDocument();
  78         final DOMResult result = new DOMResult(doc);
  79         NormalizedNodeWriter normalizedNodeWriter = null;
  80         NormalizedNodeStreamWriter normalizedNodeStreamWriter = null;
  81         XMLStreamWriter writer = null;
  82
  83         try {
  84             writer = OF.createXMLStreamWriter(result);
  85             normalizedNodeStreamWriter = XMLStreamNormalizedNodeStreamWriter.create(writer, inference);
  86             normalizedNodeWriter = NormalizedNodeWriter.forStreamWriter(normalizedNodeStreamWriter);
  87
  88             normalizedNodeWriter.write(normalized);
  89
  90             normalizedNodeWriter.flush();
  91         } finally {
  92             if (normalizedNodeWriter != null) {
  93                 normalizedNodeWriter.close();
  94             }
  95             if (normalizedNodeStreamWriter != null) {
  96                 normalizedNodeStreamWriter.close();
  97             }
  98             if (writer != null) {
  99                 writer.close();
 100             }
 101         }
 102
 103         return result;
 104     }
 105
 106     /**
 107      * Generating base element of every notification.
 108      *
 109      * @param doc
 110      *            base {@link Document}
 111      * @return element of {@link Document}
 112      */
 113     protected Element basePartDoc(final Document doc) {
 114         final Element notificationElement =
 115                 doc.createElementNS("urn:ietf:params:xml:ns:netconf:notification:1.0", "notification");
 116
 117         doc.appendChild(notificationElement);
 118
 119         final Element eventTimeElement = doc.createElement("eventTime");
 120         eventTimeElement.setTextContent(toRFC3339(Instant.now()));
 121         notificationElement.appendChild(eventTimeElement);
 122
 123         return notificationElement;
 124     }
 125
 126     /**
 127      * Generating of {@link Document} transforming to string.
 128      *
 129      * @param doc
 130      *            {@link Document} with data
 131      * @return - string from {@link Document}
 132      */
 133     protected String transformDoc(final Document doc) {
 134         final ByteArrayOutputStream out = new ByteArrayOutputStream();
 135
 136         try {
 137             final Transformer transformer = TF.newTransformer();
 138             transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "no");
 139             transformer.setOutputProperty(OutputKeys.METHOD, "xml");
 140             transformer.setOutputProperty(OutputKeys.INDENT, "yes");
 141             transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
 142             transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
 143             transformer.transform(new DOMSource(doc), new StreamResult(out));
 144         } catch (final TransformerException e) {
 145             // FIXME: this should raise an exception
 146             final String msg = "Error during transformation of Document into String";
 147             LOG.error(msg, e);
 148             return msg;
 149         }
 150
 151         return new String(out.toByteArray(), StandardCharsets.UTF_8);
 152     }
 153 }