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