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 javax.ws.rs.Produces;
  14 import javax.ws.rs.core.MediaType;
  15 import javax.ws.rs.ext.Provider;
  16 import org.eclipse.jdt.annotation.Nullable;
  17 import org.opendaylight.restconf.api.MediaTypes;
  18 import org.opendaylight.restconf.api.query.PrettyPrintParam;
  19 import org.opendaylight.restconf.nb.rfc8040.legacy.WriterParameters;
  20 import org.opendaylight.restconf.server.spi.FormattableBodySupport;
  21 import org.opendaylight.yangtools.yang.common.XMLNamespace;
  22 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifier;
  23 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  24 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  25 import org.opendaylight.yangtools.yang.data.codec.gson.JSONCodecFactorySupplier;
  26 import org.opendaylight.yangtools.yang.data.codec.gson.JSONNormalizedNodeStreamWriter;
  27 import org.opendaylight.yangtools.yang.data.spi.node.ImmutableNodes;
  28 import org.opendaylight.yangtools.yang.model.util.SchemaInferenceStack;
  29 import org.opendaylight.yangtools.yang.model.util.SchemaInferenceStack.Inference;
  30
  31 @Provider
  32 @Produces({ MediaTypes.APPLICATION_YANG_DATA_JSON, MediaType.APPLICATION_JSON })
  33 public final class JsonNormalizedNodeBodyWriter extends AbstractNormalizedNodeBodyWriter {
  34     @Override
  35     void writeData(final SchemaInferenceStack stack, final NormalizedNode data, final WriterParameters writerParameters,
  36             final PrettyPrintParam prettyPrint, final OutputStream out) throws IOException {
  37         if (!stack.isEmpty()) {
  38             stack.exit();
  39         }
  40
  41         // RESTCONF allows returning one list item. We need to wrap it in map node in order to serialize it properly
  42         final var toSerialize = data instanceof MapEntryNode mapEntry
  43             ? ImmutableNodes.newSystemMapBuilder()
  44                 .withNodeIdentifier(new NodeIdentifier(data.name().getNodeType()))
  45                 .withChild(mapEntry)
  46                 .build()
  47                 : data;
  48
  49         try (var jsonWriter = FormattableBodySupport.createJsonWriter(out, prettyPrint)) {
  50             jsonWriter.beginObject();
  51
  52             final var nnWriter = createNormalizedNodeWriter(stack.toInference(), jsonWriter, writerParameters, null);
  53             nnWriter.write(toSerialize);
  54             nnWriter.flush();
  55
  56             jsonWriter.endObject().flush();
  57         }
  58     }
  59
  60     private static RestconfNormalizedNodeWriter createNormalizedNodeWriter(final Inference inference,
  61             final JsonWriter jsonWriter, final WriterParameters writerParameters,
  62             final @Nullable XMLNamespace initialNamespace) {
  63         // TODO: Performance: Cache JSON Codec factory and schema context
  64         final var codecs = JSONCodecFactorySupplier.RFC7951.getShared(inference.modelContext());
  65         return RestconfNormalizedNodeWriter.forStreamWriter(
  66             JSONNormalizedNodeStreamWriter.createNestedWriter(codecs, inference,
  67                 initialNamespace, jsonWriter), writerParameters.depth(), writerParameters.fields());
  68     }
  69 }