yang/yang-data-codec-gson/src/test/java/org/opendaylight/yangtools/yang/data/codec/gson/retest/StreamToNormalizedNodeTest.java

   1 /*
   2  * Copyright (c) 2015 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.yangtools.yang.data.codec.gson.retest;
   9
  10 import static org.opendaylight.yangtools.yang.data.codec.gson.retest.TestUtils.loadModules;
  11 import static org.opendaylight.yangtools.yang.data.codec.gson.retest.TestUtils.loadTextFile;
  12
  13 import org.opendaylight.yangtools.yang.data.codec.gson.JSONCodecFactory;
  14 import org.opendaylight.yangtools.yang.data.codec.gson.JsonWriterFactory;
  15 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
  16
  17 import com.google.gson.stream.JsonReader;
  18 import java.io.File;
  19 import java.io.IOException;
  20 import java.io.StringReader;
  21 import java.io.StringWriter;
  22 import java.net.URISyntaxException;
  23 import org.junit.BeforeClass;
  24 import org.junit.Ignore;
  25 import org.junit.Test;
  26 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  27 import org.opendaylight.yangtools.yang.data.api.schema.DataContainerChild;
  28 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  29 import org.opendaylight.yangtools.yang.data.api.schema.stream.LoggingNormalizedNodeStreamWriter;
  30 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeStreamWriter;
  31 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeWriter;
  32 import org.opendaylight.yangtools.yang.data.codec.gson.JSONNormalizedNodeStreamWriter;
  33 import org.opendaylight.yangtools.yang.data.codec.gson.JsonParserStream;
  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.SchemaContext;
  37 import org.opendaylight.yangtools.yang.parser.spi.meta.ReactorException;
  38 import org.slf4j.Logger;
  39 import org.slf4j.LoggerFactory;
  40
  41 public class StreamToNormalizedNodeTest {
  42     private static final Logger LOG = LoggerFactory.getLogger(StreamToNormalizedNodeTest.class);
  43     private static SchemaContext schemaContext;
  44     private static String streamAsString;
  45
  46     @BeforeClass
  47     public static void initialization() throws IOException, URISyntaxException, ReactorException {
  48         schemaContext = loadModules("/complexjson/yang");
  49         streamAsString = loadTextFile(new File(StreamToNormalizedNodeTest.class.getResource(
  50                 "/complexjson/complex-json.json").toURI()));
  51     }
  52
  53     /**
  54      * Demonstrates how to log events produced by a {@link JsonReader}.
  55      *
  56      * @throws IOException
  57      */
  58     @Test
  59     public void ownStreamWriterImplementationDemonstration() throws IOException {
  60         // GSON's JsonReader reading from the loaded string (our event source)
  61         final JsonReader reader = new JsonReader(new StringReader(streamAsString));
  62
  63         // StreamWriter which outputs SLF4J events
  64         final LoggingNormalizedNodeStreamWriter logWriter = new LoggingNormalizedNodeStreamWriter();
  65
  66         // JSON -> StreamWriter parser
  67         try (final JsonParserStream jsonHandler = JsonParserStream.create(logWriter, schemaContext)) {
  68             // Process multiple readers, flush()/close() as needed
  69             jsonHandler.parse(reader);
  70         }
  71     }
  72
  73     /**
  74      * Demonstrates how to create an immutable NormalizedNode tree from a {@link JsonReader} and
  75      * then writes the data back into string representation.
  76      *
  77      * @throws IOException
  78      */
  79     @Ignore
  80     @Test
  81     public void immutableNormalizedNodeStreamWriterDemonstration() throws IOException {
  82         /*
  83          * This is the parsing part
  84          */
  85         // This is where we will output the nodes
  86         NormalizedNodeResult result = new NormalizedNodeResult();
  87
  88         // StreamWriter which attaches NormalizedNode under parent
  89         final NormalizedNodeStreamWriter streamWriter = ImmutableNormalizedNodeStreamWriter.from(result);
  90
  91         // JSON -> StreamWriter parser
  92         try (JsonParserStream handler = JsonParserStream.create(streamWriter, schemaContext)) {
  93             handler.parse(new JsonReader(new StringReader(streamAsString)));
  94         }
  95
  96         // Finally build the node
  97         final NormalizedNode<?, ?> parsedData = result.getResult();
  98         LOG.debug("Parsed NormalizedNodes: {}", parsedData);
  99
 100         /*
 101          * This is the serialization part.
 102          */
 103         // We want to write the first child out
 104         final DataContainerChild<? extends PathArgument, ?> firstChild = (DataContainerChild<? extends PathArgument, ?>) parsedData;
 105         LOG.debug("Serializing first child: {}", firstChild);
 106
 107         // String holder
 108         final StringWriter writer = new StringWriter();
 109
 110         // StreamWriter which outputs JSON strings
 111         // StreamWriter which outputs JSON strings
 112         final NormalizedNodeStreamWriter jsonStream = JSONNormalizedNodeStreamWriter.
 113                 createExclusiveWriter(JSONCodecFactory.create(schemaContext), SchemaPath.ROOT, null,
 114                     JsonWriterFactory.createJsonWriter(writer, 2));
 115
 116         // NormalizedNode -> StreamWriter
 117         final NormalizedNodeWriter nodeWriter = NormalizedNodeWriter.forStreamWriter(jsonStream);
 118
 119         // Write multiple NormalizedNodes fluently, flush()/close() as needed
 120         nodeWriter.write(firstChild).close();
 121
 122         // Just to put it somewhere
 123         LOG.debug("Serialized JSON: {}", writer.toString());
 124     }
 125
 126 }