restconf/restconf-nb/src/main/java/org/opendaylight/restconf/nb/rfc8040/jersey/providers/JsonNormalizedNodeBodyWriter.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 com.google.gson.stream.JsonWriter;
  11 import java.io.IOException;
  12 import java.io.OutputStream;
  13 import java.io.OutputStreamWriter;
  14 import java.nio.charset.StandardCharsets;
  15 import javax.ws.rs.Produces;
  16 import javax.ws.rs.core.MediaType;
  17 import javax.ws.rs.ext.Provider;
  18 import org.eclipse.jdt.annotation.Nullable;
  19 import org.opendaylight.restconf.api.MediaTypes;
  20 import org.opendaylight.restconf.api.query.PrettyPrintParam;
  21 import org.opendaylight.restconf.nb.rfc8040.jersey.providers.api.RestconfNormalizedNodeWriter;
  22 import org.opendaylight.restconf.nb.rfc8040.legacy.QueryParameters;
  23 import org.opendaylight.yangtools.yang.common.XMLNamespace;
  24 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifier;
  25 import org.opendaylight.yangtools.yang.data.api.schema.ContainerNode;
  26 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  27 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  28 import org.opendaylight.yangtools.yang.data.codec.gson.JSONCodecFactorySupplier;
  29 import org.opendaylight.yangtools.yang.data.codec.gson.JSONNormalizedNodeStreamWriter;
  30 import org.opendaylight.yangtools.yang.data.codec.gson.JsonWriterFactory;
  31 import org.opendaylight.yangtools.yang.data.spi.node.ImmutableNodes;
  32 import org.opendaylight.yangtools.yang.model.util.SchemaInferenceStack;
  33 import org.opendaylight.yangtools.yang.model.util.SchemaInferenceStack.Inference;
  34
  35 @Provider
  36 @Produces({ MediaTypes.APPLICATION_YANG_DATA_JSON, MediaType.APPLICATION_JSON })
  37 public final class JsonNormalizedNodeBodyWriter extends AbstractNormalizedNodeBodyWriter {
  38     private static final int DEFAULT_INDENT_SPACES_NUM = 2;
  39
  40     @Override
  41     void writeOperationOutput(final SchemaInferenceStack stack, final QueryParameters writerParameters,
  42             final ContainerNode output, final OutputStream entityStream) throws IOException {
  43         // RpcDefinition/ActionDefinition is not supported as initial codec in JSONStreamWriter, so we need to emit
  44         // initial output declaration
  45         try (var jsonWriter = createJsonWriter(entityStream, writerParameters.prettyPrint())) {
  46             final var module = stack.currentModule();
  47             jsonWriter.beginObject().name(module.argument().getLocalName() + ":output").beginObject();
  48
  49             final var nnWriter = createNormalizedNodeWriter(stack.toInference(), jsonWriter, writerParameters,
  50                 module.namespace().argument());
  51             writeChildren(nnWriter, output);
  52             nnWriter.flush();
  53
  54             jsonWriter.endObject().endObject();
  55         }
  56     }
  57
  58     @Override
  59     void writeData(final SchemaInferenceStack stack, final QueryParameters writerParameters, final NormalizedNode data,
  60             final OutputStream entityStream) throws IOException {
  61         if (!stack.isEmpty()) {
  62             stack.exit();
  63         }
  64
  65         // RESTCONF allows returning one list item. We need to wrap it in map node in order to serialize it properly
  66         final var toSerialize = data instanceof MapEntryNode mapEntry
  67             ? ImmutableNodes.newSystemMapBuilder()
  68                 .withNodeIdentifier(new NodeIdentifier(data.name().getNodeType()))
  69                 .withChild(mapEntry)
  70                 .build()
  71                 : data;
  72
  73         try (var jsonWriter = createJsonWriter(entityStream, writerParameters.prettyPrint())) {
  74             jsonWriter.beginObject();
  75
  76             final var nnWriter = createNormalizedNodeWriter(stack.toInference(), jsonWriter, writerParameters, null);
  77             nnWriter.write(toSerialize);
  78             nnWriter.flush();
  79
  80             jsonWriter.endObject().flush();
  81         }
  82     }
  83
  84     private static void writeChildren(final RestconfNormalizedNodeWriter nnWriter, final ContainerNode data)
  85             throws IOException {
  86         for (var child : data.body()) {
  87             nnWriter.write(child);
  88         }
  89     }
  90
  91     private static RestconfNormalizedNodeWriter createNormalizedNodeWriter(final Inference inference,
  92             final JsonWriter jsonWriter, final QueryParameters writerParameters,
  93             final @Nullable XMLNamespace initialNamespace) {
  94         // TODO: Performance: Cache JSON Codec factory and schema context
  95         final var codecs = JSONCodecFactorySupplier.RFC7951.getShared(inference.modelContext());
  96         return ParameterAwareNormalizedNodeWriter.forStreamWriter(
  97             JSONNormalizedNodeStreamWriter.createNestedWriter(codecs, inference,
  98                 initialNamespace, jsonWriter), writerParameters.depth(), writerParameters.fields());
  99     }
 100
 101     private static JsonWriter createJsonWriter(final OutputStream entityStream,
 102             final @Nullable PrettyPrintParam prettyPrint) {
 103         final var outputWriter = new OutputStreamWriter(entityStream, StandardCharsets.UTF_8);
 104         return prettyPrint != null && prettyPrint.value()
 105             ? JsonWriterFactory.createJsonWriter(outputWriter, DEFAULT_INDENT_SPACES_NUM)
 106                 : JsonWriterFactory.createJsonWriter(outputWriter);
 107     }
 108 }