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     @Test
  52     public void ownStreamWriterImplementationDemonstration() throws IOException {
  53         // GSON's JsonReader reading from the loaded string (our event source)
  54         final JsonReader reader = new JsonReader(new StringReader(streamAsString));
  55
  56         // StreamWriter which outputs SLF4J events
  57         final LoggingNormalizedNodeStreamWriter logWriter = new LoggingNormalizedNodeStreamWriter();
  58
  59         // JSON -> StreamWriter parser
  60         try (JsonParserStream jsonHandler = JsonParserStream.create(logWriter, schemaContext)) {
  61             // Process multiple readers, flush()/close() as needed
  62             jsonHandler.parse(reader);
  63         }
  64     }
  65
  66     /**
  67      * Demonstrates how to create an immutable NormalizedNode tree from a {@link JsonReader} and
  68      * then writes the data back into string representation.
  69      */
  70     @Ignore
  71     @Test
  72     public void immutableNormalizedNodeStreamWriterDemonstration() throws IOException {
  73         /*
  74          * This is the parsing part
  75          */
  76         // This is where we will output the nodes
  77         NormalizedNodeResult result = new NormalizedNodeResult();
  78
  79         // StreamWriter which attaches NormalizedNode under parent
  80         final NormalizedNodeStreamWriter streamWriter = ImmutableNormalizedNodeStreamWriter.from(result);
  81
  82         // JSON -> StreamWriter parser
  83         try (JsonParserStream handler = JsonParserStream.create(streamWriter, schemaContext)) {
  84             handler.parse(new JsonReader(new StringReader(streamAsString)));
  85         }
  86
  87         // Finally build the node
  88         final NormalizedNode<?, ?> parsedData = result.getResult();
  89         LOG.debug("Parsed NormalizedNodes: {}", parsedData);
  90
  91         /*
  92          * This is the serialization part.
  93          */
  94         // We want to write the first child out
  95         final DataContainerChild<? extends PathArgument, ?> firstChild =
  96                 (DataContainerChild<? extends PathArgument, ?>) parsedData;
  97         LOG.debug("Serializing first child: {}", firstChild);
  98
  99         // String holder
 100         final StringWriter writer = new StringWriter();
 101
 102         // StreamWriter which outputs JSON strings
 103         // StreamWriter which outputs JSON strings
 104         final NormalizedNodeStreamWriter jsonStream = JSONNormalizedNodeStreamWriter.createExclusiveWriter(
 105             JSONCodecFactory.getShared(schemaContext), SchemaPath.ROOT, null,
 106             JsonWriterFactory.createJsonWriter(writer, 2));
 107
 108         // NormalizedNode -> StreamWriter
 109         final NormalizedNodeWriter nodeWriter = NormalizedNodeWriter.forStreamWriter(jsonStream);
 110
 111         // Write multiple NormalizedNodes fluently, flush()/close() as needed
 112         nodeWriter.write(firstChild).close();
 113
 114         // Just to put it somewhere
 115         LOG.debug("Serialized JSON: {}", writer.toString());
 116     }
 117 }