restconf/restconf-nb-rfc8040/src/main/java/org/opendaylight/restconf/nb/rfc8040/jersey/providers/NormalizedNodeJsonBodyWriter.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
   9 package org.opendaylight.restconf.nb.rfc8040.jersey.providers;
  10
  11 import com.google.gson.stream.JsonWriter;
  12 import java.io.IOException;
  13 import java.io.OutputStream;
  14 import java.io.OutputStreamWriter;
  15 import java.lang.annotation.Annotation;
  16 import java.lang.reflect.Type;
  17 import java.net.URI;
  18 import java.nio.charset.StandardCharsets;
  19 import java.util.List;
  20 import java.util.Set;
  21 import javax.ws.rs.Produces;
  22 import javax.ws.rs.WebApplicationException;
  23 import javax.ws.rs.core.MediaType;
  24 import javax.ws.rs.core.MultivaluedMap;
  25 import javax.ws.rs.ext.MessageBodyWriter;
  26 import javax.ws.rs.ext.Provider;
  27 import org.opendaylight.restconf.common.context.InstanceIdentifierContext;
  28 import org.opendaylight.restconf.common.context.NormalizedNodeContext;
  29 import org.opendaylight.restconf.nb.rfc8040.Rfc8040;
  30 import org.opendaylight.restconf.nb.rfc8040.jersey.providers.api.RestconfNormalizedNodeWriter;
  31 import org.opendaylight.restconf.nb.rfc8040.utils.RestconfConstants;
  32 import org.opendaylight.yangtools.yang.common.QName;
  33 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  34 import org.opendaylight.yangtools.yang.data.api.schema.ContainerNode;
  35 import org.opendaylight.yangtools.yang.data.api.schema.DataContainerChild;
  36 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  37 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  38 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeStreamWriter;
  39 import org.opendaylight.yangtools.yang.data.codec.gson.JSONCodecFactory;
  40 import org.opendaylight.yangtools.yang.data.codec.gson.JSONCodecFactorySupplier;
  41 import org.opendaylight.yangtools.yang.data.codec.gson.JSONNormalizedNodeStreamWriter;
  42 import org.opendaylight.yangtools.yang.data.codec.gson.JsonWriterFactory;
  43 import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNodes;
  44 import org.opendaylight.yangtools.yang.model.api.DataSchemaNode;
  45 import org.opendaylight.yangtools.yang.model.api.RpcDefinition;
  46 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  47 import org.opendaylight.yangtools.yang.model.api.SchemaNode;
  48 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
  49
  50 @Provider
  51 @Produces({ Rfc8040.MediaTypes.DATA + RestconfConstants.JSON, MediaType.APPLICATION_JSON })
  52 public class NormalizedNodeJsonBodyWriter implements MessageBodyWriter<NormalizedNodeContext> {
  53
  54     private static final int DEFAULT_INDENT_SPACES_NUM = 2;
  55
  56     @Override
  57     public boolean isWriteable(final Class<?> type,
  58                                final Type genericType,
  59                                final Annotation[] annotations,
  60                                final MediaType mediaType) {
  61         return type.equals(NormalizedNodeContext.class);
  62     }
  63
  64     @Override
  65     public long getSize(final NormalizedNodeContext context,
  66                         final Class<?> type,
  67                         final Type genericType,
  68                         final Annotation[] annotations,
  69                         final MediaType mediaType) {
  70         return -1;
  71     }
  72
  73     @Override
  74     public void writeTo(final NormalizedNodeContext context,
  75                         final Class<?> type,
  76                         final Type genericType,
  77                         final Annotation[] annotations,
  78                         final MediaType mediaType,
  79                         final MultivaluedMap<String, Object> httpHeaders,
  80                         final OutputStream entityStream) throws IOException, WebApplicationException {
  81         final NormalizedNode<?, ?> data = context.getData();
  82         if (data == null) {
  83             return;
  84         }
  85
  86         @SuppressWarnings("unchecked")
  87         final InstanceIdentifierContext<SchemaNode> identifierCtx =
  88                 (InstanceIdentifierContext<SchemaNode>) context.getInstanceIdentifierContext();
  89         final SchemaPath path = identifierCtx.getSchemaNode().getPath();
  90
  91         try (JsonWriter jsonWriter = createJsonWriter(entityStream, context.getWriterParameters().isPrettyPrint())) {
  92             jsonWriter.beginObject();
  93             writeNormalizedNode(jsonWriter, path, identifierCtx, data,
  94                     context.getWriterParameters().getDepth(), context.getWriterParameters().getFields());
  95             jsonWriter.endObject();
  96             jsonWriter.flush();
  97         }
  98     }
  99
 100     private static void writeNormalizedNode(final JsonWriter jsonWriter,
 101             final SchemaPath path, final InstanceIdentifierContext<SchemaNode> context, final NormalizedNode<?, ?> data,
 102             final Integer depth, final List<Set<QName>> fields) throws IOException {
 103         final RestconfNormalizedNodeWriter nnWriter;
 104
 105         if (context.getSchemaNode() instanceof RpcDefinition) {
 106             /*
 107              *  RpcDefinition is not supported as initial codec in JSONStreamWriter,
 108              *  so we need to emit initial output declaration..
 109              */
 110             nnWriter = createNormalizedNodeWriter(
 111                     context,
 112                     ((RpcDefinition) context.getSchemaNode()).getOutput().getPath(),
 113                     jsonWriter,
 114                     depth,
 115                     fields);
 116             jsonWriter.name("output");
 117             jsonWriter.beginObject();
 118             writeChildren(nnWriter, (ContainerNode) data);
 119             jsonWriter.endObject();
 120         } else {
 121             if (SchemaPath.ROOT.equals(path)) {
 122                 nnWriter = createNormalizedNodeWriter(context, path, jsonWriter, depth, fields);
 123             } else {
 124                 nnWriter = createNormalizedNodeWriter(context, path.getParent(), jsonWriter, depth, fields);
 125             }
 126
 127             if (data instanceof MapEntryNode) {
 128                 // Restconf allows returning one list item. We need to wrap it
 129                 // in map node in order to serialize it properly
 130                 nnWriter.write(
 131                         ImmutableNodes.mapNodeBuilder(data.getNodeType()).withChild((MapEntryNode) data).build());
 132             } else {
 133                 nnWriter.write(data);
 134             }
 135         }
 136
 137         nnWriter.flush();
 138     }
 139
 140     private static void writeChildren(final RestconfNormalizedNodeWriter nnWriter,
 141                                       final ContainerNode data) throws IOException {
 142         for (final DataContainerChild<? extends PathArgument, ?> child : data.getValue()) {
 143             nnWriter.write(child);
 144         }
 145     }
 146
 147     private static RestconfNormalizedNodeWriter createNormalizedNodeWriter(
 148             final InstanceIdentifierContext<SchemaNode> context, final SchemaPath path, final JsonWriter jsonWriter,
 149             final Integer depth, final List<Set<QName>> fields) {
 150
 151         final SchemaNode schema = context.getSchemaNode();
 152         final JSONCodecFactory codecs = getCodecFactory(context);
 153
 154         final NormalizedNodeStreamWriter streamWriter = JSONNormalizedNodeStreamWriter.createNestedWriter(
 155                 codecs, path, initialNamespaceFor(schema, depth), jsonWriter);
 156
 157         return ParameterAwareNormalizedNodeWriter.forStreamWriter(streamWriter, depth, fields);
 158     }
 159
 160     private static URI initialNamespaceFor(final SchemaNode schema, final Integer depth) {
 161         if (schema instanceof RpcDefinition) {
 162             return schema.getQName().getNamespace();
 163         }
 164         // For top-level elements we always want to use namespace prefix, hence use a null initial namespace
 165         if (depth == null || depth == 0 || schema instanceof SchemaContext) {
 166             return null;
 167         }
 168         return schema instanceof DataSchemaNode && !((DataSchemaNode)schema).isAugmenting()
 169                 ? schema.getQName().getNamespace() : null;
 170     }
 171
 172     private static JsonWriter createJsonWriter(final OutputStream entityStream, final boolean prettyPrint) {
 173         if (prettyPrint) {
 174             return JsonWriterFactory.createJsonWriter(
 175                     new OutputStreamWriter(entityStream, StandardCharsets.UTF_8), DEFAULT_INDENT_SPACES_NUM);
 176         }
 177         return JsonWriterFactory.createJsonWriter(new OutputStreamWriter(entityStream, StandardCharsets.UTF_8));
 178     }
 179
 180     private static JSONCodecFactory getCodecFactory(final InstanceIdentifierContext<?> context) {
 181         // TODO: Performance: Cache JSON Codec factory and schema context
 182         return JSONCodecFactorySupplier.RFC7951.getShared(context.getSchemaContext());
 183     }
 184 }