restconf/restconf-nb/src/main/java/org/opendaylight/restconf/nb/rfc8040/jersey/providers/XmlNormalizedNodeBodyWriter.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.jersey.providers;
   9
  10 import java.io.IOException;
  11 import java.io.OutputStream;
  12 import java.nio.charset.StandardCharsets;
  13 import javanet.staxutils.IndentingXMLStreamWriter;
  14 import javax.ws.rs.Produces;
  15 import javax.ws.rs.core.MediaType;
  16 import javax.ws.rs.ext.Provider;
  17 import javax.xml.XMLConstants;
  18 import javax.xml.stream.FactoryConfigurationError;
  19 import javax.xml.stream.XMLOutputFactory;
  20 import javax.xml.stream.XMLStreamException;
  21 import javax.xml.stream.XMLStreamWriter;
  22 import org.eclipse.jdt.annotation.Nullable;
  23 import org.opendaylight.restconf.api.MediaTypes;
  24 import org.opendaylight.restconf.api.query.PrettyPrintParam;
  25 import org.opendaylight.restconf.nb.rfc8040.jersey.providers.api.RestconfNormalizedNodeWriter;
  26 import org.opendaylight.restconf.nb.rfc8040.legacy.QueryParameters;
  27 import org.opendaylight.yangtools.yang.common.QName;
  28 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifier;
  29 import org.opendaylight.yangtools.yang.data.api.schema.ContainerNode;
  30 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  31 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  32 import org.opendaylight.yangtools.yang.data.codec.xml.XMLStreamNormalizedNodeStreamWriter;
  33 import org.opendaylight.yangtools.yang.data.spi.node.ImmutableNodes;
  34 import org.opendaylight.yangtools.yang.model.util.SchemaInferenceStack;
  35 import org.opendaylight.yangtools.yang.model.util.SchemaInferenceStack.Inference;
  36
  37 @Provider
  38 @Produces({ MediaTypes.APPLICATION_YANG_DATA_XML, MediaType.APPLICATION_XML, MediaType.TEXT_XML })
  39 public final class XmlNormalizedNodeBodyWriter extends AbstractNormalizedNodeBodyWriter {
  40     private static final XMLOutputFactory XML_FACTORY;
  41
  42     static {
  43         XML_FACTORY = XMLOutputFactory.newFactory();
  44         XML_FACTORY.setProperty(XMLOutputFactory.IS_REPAIRING_NAMESPACES, true);
  45     }
  46
  47     @Override
  48     void writeData(final SchemaInferenceStack stack, final QueryParameters writerParameters, final NormalizedNode data,
  49             final OutputStream entityStream) throws IOException {
  50         final boolean isRoot;
  51         if (!stack.isEmpty()) {
  52             stack.exit();
  53             isRoot = false;
  54         } else {
  55             isRoot = true;
  56         }
  57
  58         final var xmlWriter = createXmlWriter(entityStream, writerParameters.prettyPrint());
  59         final var nnWriter = createNormalizedNodeWriter(xmlWriter, stack.toInference(), writerParameters);
  60         if (data instanceof MapEntryNode mapEntry) {
  61             // Restconf allows returning one list item. We need to wrap it
  62             // in map node in order to serialize it properly
  63             nnWriter.write(ImmutableNodes.newSystemMapBuilder()
  64                 .withNodeIdentifier(new NodeIdentifier(data.name().getNodeType()))
  65                 .addChild(mapEntry)
  66                 .build());
  67         } else if (isRoot) {
  68             if (data instanceof ContainerNode container && container.isEmpty()) {
  69                 writeEmptyDataNode(xmlWriter, container);
  70             } else {
  71                 writeAndWrapInDataNode(xmlWriter, nnWriter, data);
  72             }
  73         } else {
  74             nnWriter.write(data);
  75         }
  76         nnWriter.flush();
  77     }
  78
  79     private static XMLStreamWriter createXmlWriter(final OutputStream entityStream,
  80             final @Nullable PrettyPrintParam prettyPrint) throws IOException {
  81         final XMLStreamWriter xmlWriter;
  82         try {
  83             xmlWriter = XML_FACTORY.createXMLStreamWriter(entityStream, StandardCharsets.UTF_8.name());
  84         } catch (XMLStreamException | FactoryConfigurationError e) {
  85             throw new IOException(e);
  86         }
  87
  88         return prettyPrint != null && prettyPrint.value() ? new IndentingXMLStreamWriter(xmlWriter) : xmlWriter;
  89     }
  90
  91     private static RestconfNormalizedNodeWriter createNormalizedNodeWriter(final XMLStreamWriter xmlWriter,
  92             final Inference inference, final QueryParameters writerParameters) {
  93         return ParameterAwareNormalizedNodeWriter.forStreamWriter(
  94             XMLStreamNormalizedNodeStreamWriter.create(xmlWriter, inference),
  95             writerParameters.depth(), writerParameters.fields());
  96     }
  97
  98     private static void writeAndWrapInDataNode(final XMLStreamWriter xmlWriter,
  99             final RestconfNormalizedNodeWriter nnWriter, final NormalizedNode data) throws IOException {
 100         final QName nodeType = data.name().getNodeType();
 101         final String namespace = nodeType.getNamespace().toString();
 102         try {
 103             xmlWriter.writeStartElement(XMLConstants.DEFAULT_NS_PREFIX, nodeType.getLocalName(), namespace);
 104             xmlWriter.writeDefaultNamespace(namespace);
 105             nnWriter.write(data);
 106             xmlWriter.writeEndElement();
 107             xmlWriter.flush();
 108         } catch (XMLStreamException e) {
 109             throw new IOException("Failed to write elements", e);
 110         }
 111     }
 112
 113     private static void writeEmptyDataNode(final XMLStreamWriter xmlWriter, final ContainerNode data)
 114             throws IOException {
 115         final QName nodeType = data.name().getNodeType();
 116         final String namespace = nodeType.getNamespace().toString();
 117         try {
 118             xmlWriter.writeStartElement(XMLConstants.DEFAULT_NS_PREFIX, nodeType.getLocalName(), namespace);
 119             xmlWriter.writeDefaultNamespace(namespace);
 120             xmlWriter.writeEndElement();
 121             xmlWriter.flush();
 122         } catch (XMLStreamException e) {
 123             throw new IOException("Failed to write elements", e);
 124         }
 125     }
 126 }