yang/yang-data-codec-gson/src/test/java/org/opendaylight/yangtools/yang/data/codec/gson/StreamToNormalizedNodeTest.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.yangtools.yang.data.codec.gson;
   9
  10 import static org.opendaylight.yangtools.yang.data.codec.gson.TestUtils.loadTextFile;
  11
  12 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
  13
  14 import com.google.gson.stream.JsonReader;
  15 import java.io.File;
  16 import java.io.IOException;
  17 import java.io.StringReader;
  18 import java.io.StringWriter;
  19 import java.net.URISyntaxException;
  20 import org.junit.BeforeClass;
  21 import org.junit.Ignore;
  22 import org.junit.Test;
  23 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  24 import org.opendaylight.yangtools.yang.data.api.schema.DataContainerChild;
  25 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  26 import org.opendaylight.yangtools.yang.data.api.schema.stream.LoggingNormalizedNodeStreamWriter;
  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.impl.schema.ImmutableNormalizedNodeStreamWriter;
  30 import org.opendaylight.yangtools.yang.data.impl.schema.NormalizedNodeResult;
  31 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  32 import org.opendaylight.yangtools.yang.parser.spi.meta.ReactorException;
  33 import org.opendaylight.yangtools.yang.test.util.YangParserTestUtils;
  34 import org.slf4j.Logger;
  35 import org.slf4j.LoggerFactory;
  36
  37 public class StreamToNormalizedNodeTest {
  38     private static final Logger LOG = LoggerFactory.getLogger(StreamToNormalizedNodeTest.class);
  39     private static SchemaContext schemaContext;
  40     private static String streamAsString;
  41
  42     @BeforeClass
  43     public static void initialization() throws IOException, URISyntaxException, ReactorException {
  44         schemaContext = YangParserTestUtils.parseYangSources("/complexjson/yang");
  45         streamAsString = loadTextFile(new File(StreamToNormalizedNodeTest.class.getResource(
  46                 "/complexjson/complex-json.json").toURI()));
  47     }
  48
  49     /**
  50      * Demonstrates how to log events produced by a {@link JsonReader}.
  51      *
  52      * @throws IOException
  53      */
  54     @Test
  55     public void ownStreamWriterImplementationDemonstration() throws IOException {
  56         // GSON's JsonReader reading from the loaded string (our event source)
  57         final JsonReader reader = new JsonReader(new StringReader(streamAsString));
  58
  59         // StreamWriter which outputs SLF4J events
  60         final LoggingNormalizedNodeStreamWriter logWriter = new LoggingNormalizedNodeStreamWriter();
  61
  62         // JSON -> StreamWriter parser
  63         try (final JsonParserStream jsonHandler = JsonParserStream.create(logWriter, schemaContext)) {
  64             // Process multiple readers, flush()/close() as needed
  65             jsonHandler.parse(reader);
  66         }
  67     }
  68
  69     /**
  70      * Demonstrates how to create an immutable NormalizedNode tree from a {@link JsonReader} and
  71      * then writes the data back into string representation.
  72      *
  73      * @throws IOException
  74      */
  75     @Ignore
  76     @Test
  77     public void immutableNormalizedNodeStreamWriterDemonstration() throws IOException {
  78         /*
  79          * This is the parsing part
  80          */
  81         // This is where we will output the nodes
  82         NormalizedNodeResult result = new NormalizedNodeResult();
  83
  84         // StreamWriter which attaches NormalizedNode under parent
  85         final NormalizedNodeStreamWriter streamWriter = ImmutableNormalizedNodeStreamWriter.from(result);
  86
  87         // JSON -> StreamWriter parser
  88         try (JsonParserStream handler = JsonParserStream.create(streamWriter, schemaContext)) {
  89             handler.parse(new JsonReader(new StringReader(streamAsString)));
  90         }
  91
  92         // Finally build the node
  93         final NormalizedNode<?, ?> parsedData = result.getResult();
  94         LOG.debug("Parsed NormalizedNodes: {}", parsedData);
  95
  96         /*
  97          * This is the serialization part.
  98          */
  99         // We want to write the first child out
 100         final DataContainerChild<? extends PathArgument, ?> firstChild = (DataContainerChild<? extends PathArgument, ?>) parsedData;
 101         LOG.debug("Serializing first child: {}", firstChild);
 102
 103         // String holder
 104         final StringWriter writer = new StringWriter();
 105
 106         // StreamWriter which outputs JSON strings
 107         // StreamWriter which outputs JSON strings
 108         final NormalizedNodeStreamWriter jsonStream = JSONNormalizedNodeStreamWriter.
 109                 createExclusiveWriter(JSONCodecFactory.create(schemaContext), SchemaPath.ROOT, null,
 110                     JsonWriterFactory.createJsonWriter(writer, 2));
 111
 112         // NormalizedNode -> StreamWriter
 113         final NormalizedNodeWriter nodeWriter = NormalizedNodeWriter.forStreamWriter(jsonStream);
 114
 115         // Write multiple NormalizedNodes fluently, flush()/close() as needed
 116         nodeWriter.write(firstChild).close();
 117
 118         // Just to put it somewhere
 119         LOG.debug("Serialized JSON: {}", writer.toString());
 120     }
 121
 122 }