opendaylight/md-sal/sal-rest-connector/src/main/java/org/opendaylight/controller/sal/rest/impl/NormalizedNodeJsonBodyWriter.java

   1 /*
   2  * Copyright (c) 2014 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.controller.sal.rest.impl;
   9
  10 import com.google.common.base.Charsets;
  11 import com.google.common.base.Optional;
  12 import com.google.gson.stream.JsonWriter;
  13 import java.io.IOException;
  14 import java.io.OutputStream;
  15 import java.io.OutputStreamWriter;
  16 import java.lang.annotation.Annotation;
  17 import java.lang.reflect.Type;
  18 import java.net.URI;
  19 import javax.ws.rs.Produces;
  20 import javax.ws.rs.WebApplicationException;
  21 import javax.ws.rs.core.MediaType;
  22 import javax.ws.rs.core.MultivaluedMap;
  23 import javax.ws.rs.ext.MessageBodyWriter;
  24 import javax.ws.rs.ext.Provider;
  25 import org.opendaylight.controller.sal.rest.api.Draft02;
  26 import org.opendaylight.controller.sal.rest.api.RestconfNormalizedNodeWriter;
  27 import org.opendaylight.controller.sal.rest.api.RestconfService;
  28 import org.opendaylight.controller.sal.restconf.impl.InstanceIdentifierContext;
  29 import org.opendaylight.controller.sal.restconf.impl.NormalizedNodeContext;
  30 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  31 import org.opendaylight.yangtools.yang.data.api.schema.ContainerNode;
  32 import org.opendaylight.yangtools.yang.data.api.schema.DataContainerChild;
  33 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  34 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  35 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeStreamWriter;
  36 import org.opendaylight.yangtools.yang.data.codec.gson.JSONCodecFactory;
  37 import org.opendaylight.yangtools.yang.data.codec.gson.JSONNormalizedNodeStreamWriter;
  38 import org.opendaylight.yangtools.yang.data.codec.gson.JsonWriterFactory;
  39 import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNodes;
  40 import org.opendaylight.yangtools.yang.model.api.DataSchemaNode;
  41 import org.opendaylight.yangtools.yang.model.api.RpcDefinition;
  42 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  43 import org.opendaylight.yangtools.yang.model.api.SchemaNode;
  44 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
  45
  46 @Provider
  47 @Produces({ Draft02.MediaTypes.API + RestconfService.JSON, Draft02.MediaTypes.DATA + RestconfService.JSON,
  48     Draft02.MediaTypes.OPERATION + RestconfService.JSON, MediaType.APPLICATION_JSON })
  49 public class NormalizedNodeJsonBodyWriter implements MessageBodyWriter<NormalizedNodeContext> {
  50
  51     private static final int DEFAULT_INDENT_SPACES_NUM = 2;
  52
  53     @Override
  54     public boolean isWriteable(final Class<?> type, final Type genericType, final Annotation[] annotations, final MediaType mediaType) {
  55         return type.equals(NormalizedNodeContext.class);
  56     }
  57
  58     @Override
  59     public long getSize(final NormalizedNodeContext t, final Class<?> type, final Type genericType, final Annotation[] annotations, final MediaType mediaType) {
  60         return -1;
  61     }
  62
  63     @Override
  64     public void writeTo(final NormalizedNodeContext t, final Class<?> type, final Type genericType, final Annotation[] annotations,
  65             final MediaType mediaType, final MultivaluedMap<String, Object> httpHeaders, final OutputStream entityStream)
  66                     throws IOException, WebApplicationException {
  67         NormalizedNode<?, ?> data = t.getData();
  68         if (data == null) {
  69             return;
  70         }
  71
  72         @SuppressWarnings("unchecked")
  73         final InstanceIdentifierContext<SchemaNode> context = (InstanceIdentifierContext<SchemaNode>) t.getInstanceIdentifierContext();
  74
  75         SchemaPath path = context.getSchemaNode().getPath();
  76         final JsonWriter jsonWriter = createJsonWriter(entityStream, t.getWriterParameters().isPrettyPrint());
  77         jsonWriter.beginObject();
  78         writeNormalizedNode(jsonWriter,path,context,data, t.getWriterParameters().getDepth());
  79         jsonWriter.endObject();
  80         jsonWriter.flush();
  81     }
  82
  83     private void writeNormalizedNode(JsonWriter jsonWriter, SchemaPath path,
  84             InstanceIdentifierContext<SchemaNode> context, NormalizedNode<?, ?> data, Optional<Integer> depth) throws
  85             IOException {
  86         final RestconfNormalizedNodeWriter nnWriter;
  87         if (SchemaPath.ROOT.equals(path)) {
  88             /*
  89              *  Creates writer without initialNs and we write children of root data container
  90              *  which is not visible in restconf
  91              */
  92             nnWriter = createNormalizedNodeWriter(context,path,jsonWriter, depth);
  93             writeChildren(nnWriter,(ContainerNode) data);
  94         } else if (context.getSchemaNode() instanceof RpcDefinition) {
  95             /*
  96              *  RpcDefinition is not supported as initial codec in JSONStreamWriter,
  97              *  so we need to emit initial output declaratation..
  98              */
  99             path = ((RpcDefinition) context.getSchemaNode()).getOutput().getPath();
 100             nnWriter = createNormalizedNodeWriter(context,path,jsonWriter, depth);
 101             jsonWriter.name("output");
 102             jsonWriter.beginObject();
 103             writeChildren(nnWriter, (ContainerNode) data);
 104             jsonWriter.endObject();
 105         } else {
 106             path = path.getParent();
 107
 108             if(data instanceof MapEntryNode) {
 109                 data = ImmutableNodes.mapNodeBuilder(data.getNodeType()).withChild(((MapEntryNode) data)).build();
 110             }
 111             nnWriter = createNormalizedNodeWriter(context,path,jsonWriter, depth);
 112             nnWriter.write(data);
 113         }
 114         nnWriter.flush();
 115     }
 116
 117     private void writeChildren(final RestconfNormalizedNodeWriter nnWriter, final ContainerNode data) throws IOException {
 118         for(final DataContainerChild<? extends PathArgument, ?> child : data.getValue()) {
 119             nnWriter.write(child);
 120         }
 121     }
 122
 123     private RestconfNormalizedNodeWriter createNormalizedNodeWriter(final InstanceIdentifierContext<SchemaNode> context,
 124             final SchemaPath path, final JsonWriter jsonWriter, Optional<Integer> depth) {
 125
 126         final SchemaNode schema = context.getSchemaNode();
 127         final JSONCodecFactory codecs = getCodecFactory(context);
 128
 129         final URI initialNs;
 130         if ((schema instanceof DataSchemaNode)
 131                 && !((DataSchemaNode)schema).isAugmenting()
 132                 && !(schema instanceof SchemaContext)) {
 133             initialNs = schema.getQName().getNamespace();
 134         } else if (schema instanceof RpcDefinition) {
 135             initialNs = schema.getQName().getNamespace();
 136         } else {
 137             initialNs = null;
 138         }
 139         final NormalizedNodeStreamWriter streamWriter = JSONNormalizedNodeStreamWriter.createNestedWriter(codecs,path,initialNs,jsonWriter);
 140         if (depth.isPresent()) {
 141             return DepthAwareNormalizedNodeWriter.forStreamWriter(streamWriter, depth.get());
 142         } else {
 143             return RestconfDelegatingNormalizedNodeWriter.forStreamWriter(streamWriter);
 144         }
 145     }
 146
 147     private JsonWriter createJsonWriter(final OutputStream entityStream, boolean prettyPrint) {
 148         if (prettyPrint) {
 149             return JsonWriterFactory.createJsonWriter(new OutputStreamWriter(entityStream, Charsets.UTF_8),
 150                     DEFAULT_INDENT_SPACES_NUM);
 151         } else {
 152             return JsonWriterFactory.createJsonWriter(new OutputStreamWriter(entityStream, Charsets.UTF_8));
 153         }
 154     }
 155
 156     private JSONCodecFactory getCodecFactory(final InstanceIdentifierContext<?> context) {
 157         // TODO: Performance: Cache JSON Codec factory and schema context
 158         return JSONCodecFactory.create(context.getSchemaContext());
 159     }
 160
 161 }