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