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.Test;
  20 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  21 import org.opendaylight.yangtools.yang.data.api.schema.DataContainerChild;
  22 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  23 import org.opendaylight.yangtools.yang.data.api.schema.stream.LoggingNormalizedNodeStreamWriter;
  24 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeStreamWriter;
  25 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeWriter;
  26 import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNormalizedNodeStreamWriter;
  27 import org.opendaylight.yangtools.yang.data.impl.schema.NormalizedNodeResult;
  28 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  29 import org.opendaylight.yangtools.yang.model.api.SchemaPath;
  30 import org.opendaylight.yangtools.yang.test.util.YangParserTestUtils;
  31 import org.slf4j.Logger;
  32 import org.slf4j.LoggerFactory;
  33
  34 public class StreamToNormalizedNodeTest {
  35     private static final Logger LOG = LoggerFactory.getLogger(StreamToNormalizedNodeTest.class);
  36     private static SchemaContext schemaContext;
  37     private static String streamAsString;
  38
  39     @BeforeClass
  40     public static void initialization() throws IOException, URISyntaxException {
  41         schemaContext = YangParserTestUtils.parseYangResourceDirectory("/complexjson/yang");
  42         streamAsString = loadTextFile(new File(StreamToNormalizedNodeTest.class.getResource(
  43                 "/complexjson/complex-json.json").toURI()));
  44     }
  45
  46     /**
  47      * Demonstrates how to log events produced by a {@link JsonReader}.
  48      */
  49     @Test
  50     public void ownStreamWriterImplementationDemonstration() throws IOException {
  51         // GSON's JsonReader reading from the loaded string (our event source)
  52         final JsonReader reader = new JsonReader(new StringReader(streamAsString));
  53
  54         // StreamWriter which outputs SLF4J events
  55         final LoggingNormalizedNodeStreamWriter logWriter = new LoggingNormalizedNodeStreamWriter();
  56
  57         // JSON -> StreamWriter parser
  58         try (JsonParserStream jsonHandler = JsonParserStream.create(logWriter,
  59             JSONCodecFactorySupplier.DRAFT_LHOTKA_NETMOD_YANG_JSON_02.getShared(schemaContext))) {
  60             // Process multiple readers, flush()/close() as needed
  61             jsonHandler.parse(reader);
  62         }
  63     }
  64
  65     /**
  66      * Demonstrates how to create an immutable NormalizedNode tree from a {@link JsonReader} and
  67      * then writes the data back into string representation.
  68      */
  69     @Test
  70     public void immutableNormalizedNodeStreamWriterDemonstration() throws IOException {
  71         /*
  72          * This is the parsing part
  73          */
  74         // This is where we will output the nodes
  75         NormalizedNodeResult result = new NormalizedNodeResult();
  76
  77         // StreamWriter which attaches NormalizedNode under parent
  78         final NormalizedNodeStreamWriter streamWriter = ImmutableNormalizedNodeStreamWriter.from(result);
  79
  80         // JSON -> StreamWriter parser
  81         try (JsonParserStream handler = JsonParserStream.create(streamWriter,
  82             JSONCodecFactorySupplier.DRAFT_LHOTKA_NETMOD_YANG_JSON_02.getShared(schemaContext))) {
  83             handler.parse(new JsonReader(new StringReader(streamAsString)));
  84         }
  85
  86         // Finally build the node
  87         final NormalizedNode<?, ?> parsedData = result.getResult();
  88         LOG.debug("Parsed NormalizedNodes: {}", parsedData);
  89
  90         /*
  91          * This is the serialization part.
  92          */
  93         // We want to write the first child out
  94         final DataContainerChild<? extends PathArgument, ?> firstChild =
  95                 (DataContainerChild<? extends PathArgument, ?>) parsedData;
  96         LOG.debug("Serializing first child: {}", firstChild);
  97
  98         // String holder
  99         final StringWriter writer = new StringWriter();
 100
 101         // StreamWriter which outputs JSON strings
 102         // StreamWriter which outputs JSON strings
 103         final NormalizedNodeStreamWriter jsonStream = JSONNormalizedNodeStreamWriter.createExclusiveWriter(
 104             JSONCodecFactorySupplier.DRAFT_LHOTKA_NETMOD_YANG_JSON_02.getShared(schemaContext), SchemaPath.ROOT, null,
 105             JsonWriterFactory.createJsonWriter(writer, 2));
 106
 107         // NormalizedNode -> StreamWriter
 108         final NormalizedNodeWriter nodeWriter = NormalizedNodeWriter.forStreamWriter(jsonStream);
 109
 110         // Write multiple NormalizedNodes fluently, flush()/close() as needed
 111         nodeWriter.write(firstChild).close();
 112
 113         // Just to put it somewhere
 114         LOG.debug("Serialized JSON: {}", writer.toString());
 115     }
 116 }