common/src/main/java/org/opendaylight/transportpce/common/converter/JsonStringConverter.java

   1 /*
   2  * Copyright © 2021 Orange, 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.transportpce.common.converter;
   9
  10 import com.google.common.collect.FluentIterable;
  11 import com.google.gson.Gson;
  12 import com.google.gson.JsonObject;
  13 import com.google.gson.JsonParser;
  14 import com.google.gson.stream.JsonReader;
  15 import com.google.gson.stream.JsonWriter;
  16 import java.io.IOException;
  17 import java.io.StringReader;
  18 import java.io.StringWriter;
  19 import java.io.Writer;
  20 import org.opendaylight.mdsal.binding.dom.codec.spi.BindingDOMCodecServices;
  21 import org.opendaylight.mdsal.binding.spec.reflect.BindingReflections;
  22 import org.opendaylight.yangtools.yang.binding.DataObject;
  23 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
  24 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  25 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeStreamWriter;
  26 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeWriter;
  27 import org.opendaylight.yangtools.yang.data.codec.gson.JSONCodecFactory;
  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.JsonParserStream;
  31 import org.opendaylight.yangtools.yang.data.codec.gson.JsonWriterFactory;
  32 import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNormalizedNodeStreamWriter;
  33 import org.opendaylight.yangtools.yang.data.impl.schema.NormalizedNodeResult;
  34 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
  35 import org.slf4j.Logger;
  36 import org.slf4j.LoggerFactory;
  37
  38 public class JsonStringConverter<T extends DataObject> {
  39     private static final Logger LOG = LoggerFactory.getLogger(JsonStringConverter.class);
  40
  41     private BindingDOMCodecServices bindingDOMCodecServices;
  42
  43     public JsonStringConverter(BindingDOMCodecServices bindingDOMCodecServices) {
  44         this.bindingDOMCodecServices = bindingDOMCodecServices;
  45     }
  46
  47     /**
  48      * Create a json string from dataobject T.
  49      * @param id InstanceIdentifier
  50      * @param dataObject T
  51      * @param supplier RFC7951 or DRAFT_LHOTKA_NETMOD_YANG_JSON_02
  52      * @return Json string representation of the object
  53      * @throws IOException if something went wrong.
  54      */
  55     public String createJsonStringFromDataObject(final InstanceIdentifier<T> id, T dataObject,
  56             JSONCodecFactorySupplier supplier) throws IOException {
  57         final SchemaPath scPath = SchemaPath.create(FluentIterable.from(id.getPathArguments())
  58                 .transform(input -> BindingReflections.findQName(input.getType())), true);
  59         /*
  60          * This function needs : - context - scPath.getParent() -
  61          * scPath.getLastComponent().getNamespace(), -
  62          * JsonWriterFactory.createJsonWriter(writer)
  63          */
  64
  65         JSONCodecFactory codecFactory = supplier
  66                 .getShared(bindingDOMCodecServices.getRuntimeContext().getEffectiveModelContext());
  67         try (Writer writer = new StringWriter();
  68                 JsonWriter jsonWriter = JsonWriterFactory.createJsonWriter(writer, 4);) {
  69             NormalizedNodeStreamWriter jsonStreamWriter = JSONNormalizedNodeStreamWriter.createExclusiveWriter(
  70                     codecFactory, scPath.getParent(), scPath.getLastComponent().getNamespace(), jsonWriter);
  71             try (NormalizedNodeWriter nodeWriter = NormalizedNodeWriter.forStreamWriter(jsonStreamWriter)) {
  72                 nodeWriter.write(bindingDOMCodecServices.toNormalizedNode(id, dataObject).getValue());
  73                 nodeWriter.flush();
  74             }
  75             JsonObject asJsonObject = JsonParser.parseString(writer.toString()).getAsJsonObject();
  76             return new Gson().toJson(asJsonObject);
  77         } catch (IOException e) {
  78             LOG.error("Cannot convert object {} to string ", dataObject);
  79             throw e;
  80         }
  81     }
  82
  83     /**
  84      * Create a dataObject of T type from json string.
  85      * @param path YangInstanceIdentifier
  86      * @param jsonString String
  87      * @param supplier RFC7951 or DRAFT_LHOTKA_NETMOD_YANG_JSON_02
  88      * @return T the created object.
  89      */
  90     @SuppressWarnings("unchecked")
  91     public T createDataObjectFromJsonString(YangInstanceIdentifier path, String jsonString,
  92             JSONCodecFactorySupplier supplier) {
  93         JsonReader reader = new JsonReader(new StringReader(jsonString));
  94         NormalizedNodeResult result = new NormalizedNodeResult();
  95         try (NormalizedNodeStreamWriter streamWriter = ImmutableNormalizedNodeStreamWriter.from(result);
  96                 JsonParserStream jsonParser = JsonParserStream.create(streamWriter,
  97                         supplier
  98                                 .getShared(bindingDOMCodecServices.getRuntimeContext().getEffectiveModelContext()))) {
  99             jsonParser.parse(reader);
 100             return (T) bindingDOMCodecServices
 101                     .fromNormalizedNode(path, result.getResult()).getValue();
 102         } catch (IOException e) {
 103             LOG.warn("An error occured during parsing Json input stream", e);
 104             return null;
 105         }
 106     }
 107 }