restconf/restconf-nb/src/main/java/org/opendaylight/restconf/nb/rfc8040/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.restconf.nb.rfc8040.streams.listeners;
   9
  10 import com.google.common.util.concurrent.ListenableFuture;
  11 import java.io.ByteArrayOutputStream;
  12 import java.io.IOException;
  13 import java.nio.charset.StandardCharsets;
  14 import java.time.Instant;
  15 import java.time.OffsetDateTime;
  16 import java.time.ZoneId;
  17 import java.time.format.DateTimeFormatter;
  18 import javax.xml.stream.XMLOutputFactory;
  19 import javax.xml.stream.XMLStreamException;
  20 import javax.xml.stream.XMLStreamWriter;
  21 import javax.xml.transform.OutputKeys;
  22 import javax.xml.transform.Transformer;
  23 import javax.xml.transform.TransformerException;
  24 import javax.xml.transform.TransformerFactory;
  25 import javax.xml.transform.dom.DOMResult;
  26 import javax.xml.transform.dom.DOMSource;
  27 import javax.xml.transform.stream.StreamResult;
  28 import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
  29 import org.opendaylight.mdsal.dom.api.DOMDataBroker;
  30 import org.opendaylight.mdsal.dom.api.DOMDataTreeWriteTransaction;
  31 import org.opendaylight.restconf.nb.rfc8040.Rfc8040;
  32 import org.opendaylight.restconf.nb.rfc8040.handlers.SchemaContextHandler;
  33 import org.opendaylight.yangtools.util.xml.UntrustedXML;
  34 import org.opendaylight.yangtools.yang.common.QName;
  35 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  36 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeStreamWriter;
  37 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeWriter;
  38 import org.opendaylight.yangtools.yang.data.codec.xml.XMLStreamNormalizedNodeStreamWriter;
  39 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
  40 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
  41 import org.slf4j.Logger;
  42 import org.slf4j.LoggerFactory;
  43 import org.w3c.dom.Document;
  44 import org.w3c.dom.Element;
  45
  46 /**
  47  * Abstract class for processing and preparing data.
  48  */
  49 abstract class AbstractNotificationsData {
  50     private static final Logger LOG = LoggerFactory.getLogger(AbstractNotificationsData.class);
  51     private static final TransformerFactory TF = TransformerFactory.newInstance();
  52     private static final XMLOutputFactory OF = XMLOutputFactory.newInstance();
  53
  54     private final String localName;
  55
  56     protected SchemaContextHandler schemaHandler;
  57     private DOMDataBroker dataBroker;
  58
  59     AbstractNotificationsData(final QName lastQName) {
  60         localName = lastQName.getLocalName();
  61     }
  62
  63     /**
  64      * Data broker for delete data in DS on close().
  65      *
  66      * @param dataBroker creating new write transaction for delete data on close
  67      * @param schemaHandler for formatting notifications
  68      */
  69     @SuppressWarnings("checkstyle:hiddenField")
  70     // FIXME: this is pure lifecycle nightmare just because ...
  71     public void setCloseVars(final DOMDataBroker dataBroker, final SchemaContextHandler schemaHandler) {
  72         this.dataBroker = dataBroker;
  73         this.schemaHandler = schemaHandler;
  74     }
  75
  76     /**
  77      * Delete data in DS.
  78      */
  79     // FIXME: here we touch datastore, which probably should be done by whoever instantiated us or created the resource,
  80     //        or they should be giving us the transaction
  81     protected ListenableFuture<?> deleteDataInDS() {
  82         final DOMDataTreeWriteTransaction wTx = dataBroker.newWriteOnlyTransaction();
  83         wTx.delete(LogicalDatastoreType.OPERATIONAL, Rfc8040.restconfStateStreamPath(localName));
  84         return wTx.commit();
  85     }
  86
  87     /**
  88      * Formats data specified by RFC3339.
  89      *
  90      * @param now time stamp
  91      * @return Data specified by RFC3339.
  92      */
  93     protected static String toRFC3339(final Instant now) {
  94         return DateTimeFormatter.ISO_OFFSET_DATE_TIME.format(OffsetDateTime.ofInstant(now, ZoneId.systemDefault()));
  95     }
  96
  97     /**
  98      * Creates {@link Document} document.
  99      *
 100      * @return {@link Document} document.
 101      */
 102     protected static Document createDocument() {
 103         return UntrustedXML.newDocumentBuilder().newDocument();
 104     }
 105
 106     /**
 107      * Write normalized node to {@link DOMResult}.
 108      *
 109      * @param normalized
 110      *            data
 111      * @param context
 112      *            actual schema context
 113      * @param schemaPath
 114      *            schema path of data
 115      * @return {@link DOMResult}
 116      */
 117     protected DOMResult writeNormalizedNode(final NormalizedNode normalized, final EffectiveModelContext context,
 118             final SchemaPath schemaPath) throws IOException, XMLStreamException {
 119         final Document doc = UntrustedXML.newDocumentBuilder().newDocument();
 120         final DOMResult result = new DOMResult(doc);
 121         NormalizedNodeWriter normalizedNodeWriter = null;
 122         NormalizedNodeStreamWriter normalizedNodeStreamWriter = null;
 123         XMLStreamWriter writer = null;
 124
 125         try {
 126             writer = OF.createXMLStreamWriter(result);
 127             normalizedNodeStreamWriter = XMLStreamNormalizedNodeStreamWriter.create(writer, context, schemaPath);
 128             normalizedNodeWriter = NormalizedNodeWriter.forStreamWriter(normalizedNodeStreamWriter);
 129
 130             normalizedNodeWriter.write(normalized);
 131
 132             normalizedNodeWriter.flush();
 133         } finally {
 134             if (normalizedNodeWriter != null) {
 135                 normalizedNodeWriter.close();
 136             }
 137             if (normalizedNodeStreamWriter != null) {
 138                 normalizedNodeStreamWriter.close();
 139             }
 140             if (writer != null) {
 141                 writer.close();
 142             }
 143         }
 144
 145         return result;
 146     }
 147
 148     /**
 149      * Generating base element of every notification.
 150      *
 151      * @param doc
 152      *            base {@link Document}
 153      * @return element of {@link Document}
 154      */
 155     protected Element basePartDoc(final Document doc) {
 156         final Element notificationElement = doc.createElementNS(
 157             NotificationFormatter.NOTIFICATION_NAMESPACE, NotificationFormatter.NOTIFICATION_ELEMENT);
 158
 159         doc.appendChild(notificationElement);
 160
 161         final Element eventTimeElement = doc.createElement("eventTime");
 162         eventTimeElement.setTextContent(toRFC3339(Instant.now()));
 163         notificationElement.appendChild(eventTimeElement);
 164
 165         return notificationElement;
 166     }
 167
 168     /**
 169      * Generating of {@link Document} transforming to string.
 170      *
 171      * @param doc
 172      *            {@link Document} with data
 173      * @return - string from {@link Document}
 174      */
 175     protected String transformDoc(final Document doc) {
 176         final ByteArrayOutputStream out = new ByteArrayOutputStream();
 177
 178         try {
 179             final Transformer transformer = TF.newTransformer();
 180             transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "no");
 181             transformer.setOutputProperty(OutputKeys.METHOD, "xml");
 182             transformer.setOutputProperty(OutputKeys.INDENT, "yes");
 183             transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
 184             transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
 185             transformer.transform(new DOMSource(doc), new StreamResult(out));
 186         } catch (final TransformerException e) {
 187             // FIXME: this should raise an exception
 188             final String msg = "Error during transformation of Document into String";
 189             LOG.error(msg, e);
 190             return msg;
 191         }
 192
 193         return new String(out.toByteArray(), StandardCharsets.UTF_8);
 194     }
 195 }