restconf/sal-rest-connector/src/main/java/org/opendaylight/restconf/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.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.netconf.sal.rest.api.RestconfNormalizedNodeWriter;
  28 import org.opendaylight.netconf.sal.restconf.impl.InstanceIdentifierContext;
  29 import org.opendaylight.netconf.sal.restconf.impl.NormalizedNodeContext;
  30 import org.opendaylight.restconf.Draft17;
  31 import org.opendaylight.restconf.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.JSONNormalizedNodeStreamWriter;
  41 import org.opendaylight.yangtools.yang.data.codec.gson.JsonWriterFactory;
  42 import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNodes;
  43 import org.opendaylight.yangtools.yang.model.api.DataSchemaNode;
  44 import org.opendaylight.yangtools.yang.model.api.RpcDefinition;
  45 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  46 import org.opendaylight.yangtools.yang.model.api.SchemaNode;
  47 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
  48
  49 @Provider
  50 @Produces({ Draft17.MediaTypes.DATA + RestconfConstants.JSON, MediaType.APPLICATION_JSON })
  51 public class NormalizedNodeJsonBodyWriter implements MessageBodyWriter<NormalizedNodeContext> {
  52
  53     private static final int DEFAULT_INDENT_SPACES_NUM = 2;
  54
  55     @Override
  56     public boolean isWriteable(final Class<?> type,
  57                                final Type genericType,
  58                                final Annotation[] annotations,
  59                                final MediaType mediaType) {
  60         return type.equals(NormalizedNodeContext.class);
  61     }
  62
  63     @Override
  64     public long getSize(final NormalizedNodeContext t,
  65                         final Class<?> type,
  66                         final Type genericType,
  67                         final Annotation[] annotations,
  68                         final MediaType mediaType) {
  69         return -1;
  70     }
  71
  72     @Override
  73     public void writeTo(final NormalizedNodeContext t,
  74                         final Class<?> type,
  75                         final Type genericType,
  76                         final Annotation[] annotations,
  77                         final MediaType mediaType,
  78                         final MultivaluedMap<String, Object> httpHeaders,
  79                         final OutputStream entityStream) throws IOException, WebApplicationException {
  80         final NormalizedNode<?, ?> data = t.getData();
  81         if (data == null) {
  82             return;
  83         }
  84
  85         @SuppressWarnings("unchecked")
  86         final InstanceIdentifierContext<SchemaNode> context =
  87                 (InstanceIdentifierContext<SchemaNode>) t.getInstanceIdentifierContext();
  88         final SchemaPath path = context.getSchemaNode().getPath();
  89         final JsonWriter jsonWriter = createJsonWriter(entityStream,
  90                 t.getWriterParameters().isPrettyPrint());
  91
  92         jsonWriter.beginObject();
  93         writeNormalizedNode(jsonWriter, path, context, data,
  94                 t.getWriterParameters().getDepth(), t.getWriterParameters().getFields());
  95         jsonWriter.endObject();
  96         jsonWriter.flush();
  97     }
  98
  99     private void writeNormalizedNode(final JsonWriter jsonWriter,
 100                                      final SchemaPath path,
 101                                      final InstanceIdentifierContext<SchemaNode> context,
 102                                      final NormalizedNode<?, ?> data,
 103                                      final Integer depth,
 104                                      final List<Set<QName>> fields) throws IOException {
 105         final RestconfNormalizedNodeWriter nnWriter;
 106
 107         if (context.getSchemaNode() instanceof RpcDefinition) {
 108             /*
 109              *  RpcDefinition is not supported as initial codec in JSONStreamWriter,
 110              *  so we need to emit initial output declaration..
 111              */
 112             nnWriter = createNormalizedNodeWriter(
 113                     context,
 114                     ((RpcDefinition) context.getSchemaNode()).getOutput().getPath(),
 115                     jsonWriter,
 116                     depth,
 117                     fields);
 118             jsonWriter.name("output");
 119             jsonWriter.beginObject();
 120             writeChildren(nnWriter, (ContainerNode) data);
 121             jsonWriter.endObject();
 122         } else {
 123             if (SchemaPath.ROOT.equals(path)) {
 124                 nnWriter = createNormalizedNodeWriter(context, path, jsonWriter, depth, fields);
 125             } else {
 126                 nnWriter = createNormalizedNodeWriter(context, path.getParent(), jsonWriter, depth, fields);
 127             }
 128
 129             if (data instanceof MapEntryNode) {
 130                 // Restconf allows returning one list item. We need to wrap it
 131                 // in map node in order to serialize it properly
 132                 nnWriter.write(
 133                         ImmutableNodes.mapNodeBuilder(data.getNodeType()).withChild(((MapEntryNode) data)).build());
 134             } else {
 135                 nnWriter.write(data);
 136             }
 137         }
 138
 139         nnWriter.flush();
 140     }
 141
 142     private void writeChildren(final RestconfNormalizedNodeWriter nnWriter,
 143                                final ContainerNode data) throws IOException {
 144         for (final DataContainerChild<? extends PathArgument, ?> child : data.getValue()) {
 145             nnWriter.write(child);
 146         }
 147     }
 148
 149     private RestconfNormalizedNodeWriter createNormalizedNodeWriter(final InstanceIdentifierContext<SchemaNode> context,
 150                                                                     final SchemaPath path,
 151                                                                     final JsonWriter jsonWriter,
 152                                                                     final Integer depth,
 153                                                                     final List<Set<QName>> fields) {
 154
 155         final SchemaNode schema = context.getSchemaNode();
 156         final JSONCodecFactory codecs = getCodecFactory(context);
 157
 158         final URI initialNs;
 159         if ((schema instanceof DataSchemaNode)
 160                 && !((DataSchemaNode)schema).isAugmenting()
 161                 && !(schema instanceof SchemaContext)) {
 162             initialNs = schema.getQName().getNamespace();
 163         } else if (schema instanceof RpcDefinition) {
 164             initialNs = schema.getQName().getNamespace();
 165         } else {
 166             initialNs = null;
 167         }
 168         final NormalizedNodeStreamWriter streamWriter = JSONNormalizedNodeStreamWriter.createNestedWriter(
 169                 codecs, path, initialNs, jsonWriter);
 170         return ParameterAwareNormalizedNodeWriter.forStreamWriter(streamWriter, depth, fields);
 171     }
 172
 173     private JsonWriter createJsonWriter(final OutputStream entityStream, final boolean prettyPrint) {
 174         if (prettyPrint) {
 175             return JsonWriterFactory.createJsonWriter(
 176                     new OutputStreamWriter(entityStream, StandardCharsets.UTF_8), DEFAULT_INDENT_SPACES_NUM);
 177         } else {
 178             return JsonWriterFactory.createJsonWriter(new OutputStreamWriter(entityStream, StandardCharsets.UTF_8));
 179         }
 180     }
 181
 182     private JSONCodecFactory getCodecFactory(final InstanceIdentifierContext<?> context) {
 183         // TODO: Performance: Cache JSON Codec factory and schema context
 184         return JSONCodecFactory.create(context.getSchemaContext());
 185     }
 186 }