org.apache.tinkerpop.gremlin.structure.io.graphml.GraphMLWriter Java Examples

/**
 * Only need to execute this test with TinkerGraph or other graphs that support user supplied identifiers.
 */
@Test
@FeatureRequirement(featureClass = Graph.Features.EdgeFeatures.class, feature = Graph.Features.EdgeFeatures.FEATURE_ADD_EDGES)
@FeatureRequirement(featureClass = Graph.Features.VertexFeatures.class, feature = Graph.Features.VertexFeatures.FEATURE_ADD_VERTICES)
@FeatureRequirement(featureClass = VertexPropertyFeatures.class, feature = FEATURE_STRING_VALUES)
@FeatureRequirement(featureClass = VertexPropertyFeatures.class, feature = FEATURE_INTEGER_VALUES)
@FeatureRequirement(featureClass = EdgePropertyFeatures.class, feature = EdgePropertyFeatures.FEATURE_FLOAT_VALUES)
@FeatureRequirement(featureClass = Graph.Features.VertexFeatures.class, feature = Graph.Features.VertexFeatures.FEATURE_USER_SUPPLIED_IDS)
@FeatureRequirement(featureClass = Graph.Features.VertexFeatures.class, feature = Graph.Features.VertexFeatures.FEATURE_NUMERIC_IDS)
@LoadGraphWith(LoadGraphWith.GraphData.CLASSIC)
public void shouldWriteNormalizedGraphML() throws Exception {
    try (ByteArrayOutputStream bos = new ByteArrayOutputStream()) {
        final GraphMLWriter w = GraphMLWriter.build().normalize(true).create();
        w.writeGraph(bos, graph);
        final String expected = streamToString(getResourceAsStream(GraphMLResourceAccess.class, "tinkerpop-classic-normalized.xml"));
        assertEquals(expected.replace("\n", "").replace("\r", ""), bos.toString().replace("\n", "").replace("\r", ""));
    }
}
 

@Override
public void renderGraph(GraphContext context)
{
    Path outputFolder = createOutputFolder(context, "graphml");
    Path outputFile = outputFolder.resolve("graph.graphml");

    GraphMLWriter graphML = GraphMLWriter.build().create();
    try
    {
        graphML.writeGraph(new FileOutputStream(outputFile.toFile()), context.getGraph());
    }
    catch (Exception e)
    {
        throw new RuntimeException(e);
    }
}
 

/**
 * No assertions.  Just write out the graph for convenience.
 */
@Test
public void shouldWriteClassicGraphAsGraphML() throws IOException {
    try (final OutputStream os = new FileOutputStream(tempPath + "tinkerpop-classic.xml")) {
        GraphMLWriter.build().create().writeGraph(os, TinkerFactory.createClassic());
    }
}
 

/**
 * No assertions.  Just write out the graph for convenience.
 */
@Test
public void shouldWriteModernGraphAsGraphML() throws IOException {
    try (final OutputStream os = new FileOutputStream(tempPath + "tinkerpop-modern.xml")) {
        GraphMLWriter.build().create().writeGraph(os, TinkerFactory.createModern());
    }
}
 

@Test
@FeatureRequirement(featureClass = Graph.Features.EdgeFeatures.class, feature = Graph.Features.EdgeFeatures.FEATURE_ADD_EDGES)
@FeatureRequirement(featureClass = Graph.Features.EdgeFeatures.class, feature = Graph.Features.EdgeFeatures.FEATURE_REMOVE_EDGES)
@FeatureRequirement(featureClass = Graph.Features.VertexFeatures.class, feature = Graph.Features.VertexFeatures.FEATURE_ADD_VERTICES)
@FeatureRequirement(featureClass = Graph.Features.VertexFeatures.class, feature = Graph.Features.VertexFeatures.FEATURE_REMOVE_VERTICES)
@FeatureRequirement(featureClass = VertexPropertyFeatures.class, feature = FEATURE_STRING_VALUES)
@FeatureRequirement(featureClass = VertexPropertyFeatures.class, feature = FEATURE_INTEGER_VALUES)
@FeatureRequirement(featureClass = EdgePropertyFeatures.class, feature = EdgePropertyFeatures.FEATURE_FLOAT_VALUES)
@FeatureRequirement(featureClass = EdgePropertyFeatures.class, feature = EdgePropertyFeatures.FEATURE_STRING_VALUES)
public void shouldReadGraphMLWithCommonVertexAndEdgePropertyNames() throws IOException {
    final GraphReader reader = GraphMLReader.build().create();
    try (final InputStream stream = new ByteArrayInputStream(CLASSIC_GRAPH_WITH_COLOR.getBytes("UTF-8"))) {
        reader.readGraph(stream, graph);
    }

    // there is also a "color" property on this dataset that is on both edges and vertices
    graph.vertices().forEachRemaining(v -> assertEquals("#6495ed", v.value("color")));
    graph.edges().forEachRemaining(e -> assertEquals("#ee0000", e.value("color")));

    final GraphWriter writer = GraphMLWriter.build().create();
    try (final OutputStream out = new ByteArrayOutputStream()) {
        writer.writeGraph(out, graph);

        graph.vertices().forEachRemaining(Element::remove);
        try (final InputStream stream = new ByteArrayInputStream(((ByteArrayOutputStream) out).toByteArray())) {
            reader.readGraph(stream, graph);
        }

        // there is also a "color" property on this dataset that is on both edges and vertices
        graph.vertices().forEachRemaining(v -> assertEquals("#6495ed", v.value("color")));
        graph.edges().forEachRemaining(e -> assertEquals("#ee0000", e.value("color")));
    }
}
 

@Test
@LoadGraphWith(LoadGraphWith.GraphData.CREW)
public void shouldNotWriteGraphMLFromGraphWithMultiProperties() throws Exception {
    try (ByteArrayOutputStream bos = new ByteArrayOutputStream()) {
        final GraphMLWriter w = GraphMLWriter.build().create();
        w.writeGraph(bos, graph);
        fail("Should not be able to write multi-properties to GraphML");
    } catch (IllegalStateException iae) {
        assertThat(iae.getMessage(), containsString("multi-properties are not directly supported by GraphML format"));
    }
}
 

/**
 * Note: this is only a very lightweight test of writer/reader encoding. It is known that there are characters
 * which, when written by GraphMLWriter, cause parse errors for GraphMLReader. However, this happens uncommonly
 * enough that is not yet known which characters those are. Only need to execute this test with TinkerGraph
 * or other graphs that support user supplied identifiers.
 */
@Test
@FeatureRequirement(featureClass = Graph.Features.EdgeFeatures.class, feature = Graph.Features.EdgeFeatures.FEATURE_ADD_EDGES)
@FeatureRequirement(featureClass = Graph.Features.VertexFeatures.class, feature = Graph.Features.VertexFeatures.FEATURE_ADD_VERTICES)
@FeatureRequirement(featureClass = VertexPropertyFeatures.class, feature = FEATURE_STRING_VALUES)
@FeatureRequirement(featureClass = Graph.Features.VertexFeatures.class, feature = FEATURE_USER_SUPPLIED_IDS)
@FeatureRequirement(featureClass = Graph.Features.VertexFeatures.class, feature = Graph.Features.VertexFeatures.FEATURE_STRING_IDS)
public void shouldProperlyEncodeWithGraphML() throws Exception {
    assumeThat("GraphML web site is down so XSD cannot be retrieved", is(isGraphMLXSDPresent()));

    final Vertex v = graph.addVertex(T.id, "1");
    v.property(VertexProperty.Cardinality.single, "text", "\u00E9");

    final GraphMLWriter w = GraphMLWriter.build().create();

    final File f = TestHelper.generateTempFile(this.getClass(), "test", ".txt");
    try (final OutputStream out = new FileOutputStream(f)) {
        w.writeGraph(out, graph);
    }

    validateXmlAgainstGraphMLXsd(f);

    // reusing the same config used for creation of "g".
    final Configuration configuration = graphProvider.newGraphConfiguration("g2", this.getClass(), name.getMethodName(), null);
    graphProvider.clear(configuration);
    final Graph g2 = graphProvider.openTestGraph(configuration);
    final GraphMLReader r = GraphMLReader.build().create();

    try (final InputStream in = new FileInputStream(f)) {
        r.readGraph(in, g2);
    }

    final Vertex v2 = g2.vertices("1").next();
    assertEquals("\u00E9", v2.property("text").value());

    // need to manually close the "g2" instance
    graphProvider.clear(g2, configuration);
}
 

/**
 * No assertions.  Just write out the graph for convenience.
 */
@Test
public void shouldWriteClassicGraphAsGraphML() throws IOException {
    try (final OutputStream os = new FileOutputStream(new File(tempPath, "tinkerpop-classic.xml"))) {
        GraphMLWriter.build().create().writeGraph(os, TinkerFactory.createClassic());
    }
}
 

/**
 * No assertions.  Just write out the graph for convenience.
 */
@Test
public void shouldWriteModernGraphAsGraphML() throws IOException {
    try (final OutputStream os = new FileOutputStream(new File(tempPath, "tinkerpop-modern.xml"))) {
        GraphMLWriter.build().create().writeGraph(os, TinkerFactory.createModern());
    }
}