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