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.gson.Gson;
  11 import com.google.gson.JsonObject;
  12 import com.google.gson.JsonParser;
  13 import com.google.gson.stream.JsonReader;
  14 import com.google.gson.stream.JsonWriter;
  15 import java.io.IOException;
  16 import java.io.InputStream;
  17 import java.io.InputStreamReader;
  18 import java.io.Reader;
  19 import java.io.StringReader;
  20 import java.io.StringWriter;
  21 import java.io.Writer;
  22 import java.nio.charset.StandardCharsets;
  23 import org.opendaylight.mdsal.binding.dom.codec.spi.BindingDOMCodecServices;
  24 import org.opendaylight.yangtools.yang.binding.DataObject;
  25 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
  26 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  27 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeStreamWriter;
  28 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeWriter;
  29 import org.opendaylight.yangtools.yang.data.codec.gson.JSONCodecFactory;
  30 import org.opendaylight.yangtools.yang.data.codec.gson.JSONCodecFactorySupplier;
  31 import org.opendaylight.yangtools.yang.data.codec.gson.JSONNormalizedNodeStreamWriter;
  32 import org.opendaylight.yangtools.yang.data.codec.gson.JsonParserStream;
  33 import org.opendaylight.yangtools.yang.data.codec.gson.JsonWriterFactory;
  34 import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNormalizedNodeStreamWriter;
  35 import org.opendaylight.yangtools.yang.data.impl.schema.NormalizedNodeResult;
  36 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
  37 import org.opendaylight.yangtools.yang.model.api.EffectiveStatementInference;
  38 import org.opendaylight.yangtools.yang.model.util.SchemaInferenceStack;
  39 import org.slf4j.Logger;
  40 import org.slf4j.LoggerFactory;
  41
  42 public class JsonStringConverter<T extends DataObject> {
  43     private static final Logger LOG = LoggerFactory.getLogger(JsonStringConverter.class);
  44
  45     private BindingDOMCodecServices bindingDOMCodecServices;
  46
  47     public JsonStringConverter(BindingDOMCodecServices bindingDOMCodecServices) {
  48         this.bindingDOMCodecServices = bindingDOMCodecServices;
  49     }
  50
  51     /**
  52      * Create a json string from dataobject T.
  53      * @param id InstanceIdentifier
  54      * @param dataObject T
  55      * @param supplier RFC7951 or DRAFT_LHOTKA_NETMOD_YANG_JSON_02
  56      * @return Json string representation of the object
  57      * @throws IOException if something went wrong.
  58      */
  59     public String createJsonStringFromDataObject(final InstanceIdentifier<T> id, T dataObject,
  60             JSONCodecFactorySupplier supplier) throws IOException {
  61         /*
  62          * This function needs : - context - scPath.getParent() -
  63          * scPath.getLastComponent().getNamespace(), -
  64          * JsonWriterFactory.createJsonWriter(writer)
  65          */
  66
  67         JSONCodecFactory codecFactory = supplier
  68                 .getShared(bindingDOMCodecServices.getRuntimeContext().getEffectiveModelContext());
  69         try (Writer writer = new StringWriter();
  70                 JsonWriter jsonWriter = JsonWriterFactory.createJsonWriter(writer, 4)) {
  71             EffectiveStatementInference rootNode = SchemaInferenceStack
  72                 .of(bindingDOMCodecServices.getRuntimeContext().getEffectiveModelContext())
  73                 .toInference();
  74             rootNode.getEffectiveModelContext();
  75             rootNode.getEffectiveModelContext();
  76             NormalizedNodeStreamWriter jsonStreamWriter = JSONNormalizedNodeStreamWriter
  77                 .createExclusiveWriter(codecFactory, rootNode, EffectiveModelContext.NAME.getNamespace(), jsonWriter);
  78             try (NormalizedNodeWriter nodeWriter = NormalizedNodeWriter.forStreamWriter(jsonStreamWriter)) {
  79                 nodeWriter.write(bindingDOMCodecServices.toNormalizedNode(id, dataObject).getValue());
  80                 nodeWriter.flush();
  81             }
  82             JsonObject asJsonObject = JsonParser.parseString(writer.toString()).getAsJsonObject();
  83             return new Gson().toJson(asJsonObject);
  84         } catch (IOException e) {
  85             LOG.error("Cannot convert object {} to string ", dataObject);
  86             throw e;
  87         }
  88     }
  89
  90     /**
  91      * Create a dataObject of T type from json string.
  92      * @param path YangInstanceIdentifier
  93      * @param jsonString String
  94      * @param supplier RFC7951 or DRAFT_LHOTKA_NETMOD_YANG_JSON_02
  95      * @return T the created object.
  96      */
  97     @SuppressWarnings("unchecked")
  98     public T createDataObjectFromJsonString(YangInstanceIdentifier path, String jsonString,
  99             JSONCodecFactorySupplier supplier) {
 100         return createDataObjectFromReader(path, new StringReader(jsonString), supplier);
 101     }
 102
 103     public T createDataObjectFromInputStream(YangInstanceIdentifier path, InputStream jsonStream,
 104                                             JSONCodecFactorySupplier supplier) {
 105         return createDataObjectFromReader(path, new InputStreamReader(jsonStream, StandardCharsets.UTF_8), supplier);
 106     }
 107
 108     /**
 109      * Create a dataObject of T type from Reader.
 110      * @param path YangInstanceIdentifier
 111      * @param inputReader Reader (could be all class implementing Reader) containing Json data.
 112      * @param supplier RFC7951 or DRAFT_LHOTKA_NETMOD_YANG_JSON_02
 113      * @return the created object.
 114      */
 115     private T createDataObjectFromReader(YangInstanceIdentifier path, Reader inputReader,
 116                                          JSONCodecFactorySupplier supplier) {
 117
 118         NormalizedNodeResult result = new NormalizedNodeResult();
 119         try (JsonReader reader = new JsonReader(inputReader);
 120              NormalizedNodeStreamWriter streamWriter = ImmutableNormalizedNodeStreamWriter.from(result);
 121              JsonParserStream jsonParser = JsonParserStream
 122                      .create(
 123                              streamWriter,
 124                              supplier.getShared(bindingDOMCodecServices
 125                                      .getRuntimeContext().getEffectiveModelContext()))) {
 126             jsonParser.parse(reader);
 127             return (T) bindingDOMCodecServices.fromNormalizedNode(path, result.getResult()).getValue();
 128         } catch (IOException e) {
 129             LOG.warn("An error occured during parsing input reader", e);
 130             return null;
 131         }
 132     }
 133 }