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.api.EffectiveModelContext;
  33 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
  34 import org.slf4j.Logger;
  35 import org.slf4j.LoggerFactory;
  36 import org.w3c.dom.Document;
  37 import org.w3c.dom.Element;
  38
  39 /**
  40  * Abstract class for processing and preparing data.
  41  *
  42  */
  43 abstract class AbstractNotificationsData {
  44     private static final Logger LOG = LoggerFactory.getLogger(AbstractNotificationsData.class);
  45     private static final TransformerFactory TF = TransformerFactory.newInstance();
  46     private static final XMLOutputFactory OF = XMLOutputFactory.newFactory();
  47
  48     /**
  49      * Formats data specified by RFC3339.
  50      *
  51      * @param now time stamp
  52      * @return Data specified by RFC3339.
  53      */
  54     protected static String toRFC3339(final Instant now) {
  55         return DateTimeFormatter.ISO_OFFSET_DATE_TIME.format(OffsetDateTime.ofInstant(now, ZoneId.systemDefault()));
  56     }
  57
  58     /**
  59      * Creates {@link Document} document.
  60      *
  61      * @return {@link Document} document.
  62      */
  63     protected static Document createDocument() {
  64         return UntrustedXML.newDocumentBuilder().newDocument();
  65     }
  66
  67     /**
  68      * Write normalized node to {@link DOMResult}.
  69      *
  70      * @param normalized
  71      *            data
  72      * @param context
  73      *            actual schema context
  74      * @param schemaPath
  75      *            schema path of data
  76      * @return {@link DOMResult}
  77      */
  78     protected DOMResult writeNormalizedNode(final NormalizedNode normalized, final EffectiveModelContext context,
  79             final SchemaPath schemaPath) throws IOException, XMLStreamException {
  80         final Document doc = UntrustedXML.newDocumentBuilder().newDocument();
  81         final DOMResult result = new DOMResult(doc);
  82         NormalizedNodeWriter normalizedNodeWriter = null;
  83         NormalizedNodeStreamWriter normalizedNodeStreamWriter = null;
  84         XMLStreamWriter writer = null;
  85
  86         try {
  87             writer = OF.createXMLStreamWriter(result);
  88             normalizedNodeStreamWriter = XMLStreamNormalizedNodeStreamWriter.create(writer, context, schemaPath);
  89             normalizedNodeWriter = NormalizedNodeWriter.forStreamWriter(normalizedNodeStreamWriter);
  90
  91             normalizedNodeWriter.write(normalized);
  92
  93             normalizedNodeWriter.flush();
  94         } finally {
  95             if (normalizedNodeWriter != null) {
  96                 normalizedNodeWriter.close();
  97             }
  98             if (normalizedNodeStreamWriter != null) {
  99                 normalizedNodeStreamWriter.close();
 100             }
 101             if (writer != null) {
 102                 writer.close();
 103             }
 104         }
 105
 106         return result;
 107     }
 108
 109     /**
 110      * Generating base element of every notification.
 111      *
 112      * @param doc
 113      *            base {@link Document}
 114      * @return element of {@link Document}
 115      */
 116     protected Element basePartDoc(final Document doc) {
 117         final Element notificationElement =
 118                 doc.createElementNS("urn:ietf:params:xml:ns:netconf:notification:1.0", "notification");
 119
 120         doc.appendChild(notificationElement);
 121
 122         final Element eventTimeElement = doc.createElement("eventTime");
 123         eventTimeElement.setTextContent(toRFC3339(Instant.now()));
 124         notificationElement.appendChild(eventTimeElement);
 125
 126         return notificationElement;
 127     }
 128
 129     /**
 130      * Generating of {@link Document} transforming to string.
 131      *
 132      * @param doc
 133      *            {@link Document} with data
 134      * @return - string from {@link Document}
 135      */
 136     protected String transformDoc(final Document doc) {
 137         final ByteArrayOutputStream out = new ByteArrayOutputStream();
 138
 139         try {
 140             final Transformer transformer = TF.newTransformer();
 141             transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "no");
 142             transformer.setOutputProperty(OutputKeys.METHOD, "xml");
 143             transformer.setOutputProperty(OutputKeys.INDENT, "yes");
 144             transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
 145             transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
 146             transformer.transform(new DOMSource(doc), new StreamResult(out));
 147         } catch (final TransformerException e) {
 148             // FIXME: this should raise an exception
 149             final String msg = "Error during transformation of Document into String";
 150             LOG.error(msg, e);
 151             return msg;
 152         }
 153
 154         return new String(out.toByteArray(), StandardCharsets.UTF_8);
 155     }
 156 }