#2674 Json export (#2676)

* Initial implementation, work in progress

* Add tests and UI

* Minor tweaks

* Do not export undirected for each edge when undirected

* Formatting

* Fix color and options

modules/CoreLibraryWrapper/pom.xml

@@ -24,7 +24,7 @@
         <gephi.jfreechart.version>1.0.19</gephi.jfreechart.version>
         <gephi.pdfbox.version>2.0.27</gephi.pdfbox.version>
         <gephi.trove4j.version>3.0.3</gephi.trove4j.version>
-        <gephi.gson.version>2.9.1</gephi.gson.version>
+        <gephi.gson.version>2.10</gephi.gson.version>
     </properties>
 
     <dependencies>

modules/ExportPlugin/pom.xml

@@ -31,6 +31,10 @@
             <groupId>${project.groupId}</groupId>
             <artifactId>utils-longtask</artifactId>
         </dependency>
+        <dependency>
+            <groupId>${project.groupId}</groupId>
+            <artifactId>utils</artifactId>
+        </dependency>
         <dependency>
             <groupId>${project.groupId}</groupId>
             <artifactId>core-library-wrapper</artifactId>

modules/ExportPlugin/src/main/java/org/gephi/io/exporter/plugin/ExporterBuilderJson.java

+package org.gephi.io.exporter.plugin;
+
+import org.gephi.io.exporter.api.FileType;
+import org.gephi.io.exporter.spi.GraphExporter;
+import org.gephi.io.exporter.spi.GraphFileExporterBuilder;
+import org.openide.util.NbBundle;
+import org.openide.util.lookup.ServiceProvider;
+
+@ServiceProvider(service = GraphFileExporterBuilder.class)
+public class ExporterBuilderJson implements GraphFileExporterBuilder {
+
+    @Override
+    public GraphExporter buildExporter() {
+        return new ExporterJson();
+    }
+
+    @Override
+    public FileType[] getFileTypes() {
+        FileType ft = new FileType(".json", NbBundle.getMessage(ExporterBuilderJson.class, "fileType_Json_Name"));
+        return new FileType[] {ft};
+    }
+
+    @Override
+    public String getName() {
+        return "Json";
+    }
+}

modules/ExportPlugin/src/main/java/org/gephi/io/exporter/plugin/ExporterJson.java

+package org.gephi.io.exporter.plugin;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.TypeAdapter;
+import com.google.gson.TypeAdapterFactory;
+import com.google.gson.reflect.TypeToken;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
+import org.gephi.graph.api.*;
+import org.gephi.io.exporter.spi.CharacterExporter;
+import org.gephi.io.exporter.spi.GraphExporter;
+import org.gephi.project.api.Workspace;
+import org.gephi.utils.VersionUtils;
+import org.gephi.utils.longtask.spi.LongTask;
+import org.gephi.utils.progress.Progress;
+import org.gephi.utils.progress.ProgressTicket;
+import org.joda.time.DateTimeZone;
+import org.openide.util.Lookup;
+
+import java.awt.*;
+import java.io.IOException;
+import java.io.Writer;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class ExporterJson implements GraphExporter, CharacterExporter, LongTask {
+
+    // Architecture
+    private boolean cancel = false;
+    private ProgressTicket progress;
+    private Workspace workspace;
+    private boolean exportVisible;
+    private Writer writer;
+    private Graph graph;
+    // Settings
+    private boolean normalize = false;
+    private boolean exportColors = true;
+    private boolean exportPosition = true;
+    private boolean exportSize = true;
+    private boolean exportAttributes = true;
+    private boolean exportDynamic = true;
+    private boolean exportMeta = true;
+    private boolean prettyPrint = true;
+
+    // Helper
+    private NormalizationHelper normalization;
+
+    // Formats
+    public enum Format {Graphology}
+
+    private Format format = Format.Graphology;
+
+    @Override
+    public boolean execute() {
+        GraphController graphController = Lookup.getDefault().lookup(GraphController.class);
+        GraphModel graphModel = graphController.getGraphModel(workspace);
+        graph = exportVisible ? graphModel.getGraphVisible() : graphModel.getGraph();
+
+        Progress.start(progress);
+        graph.readLock();
+
+        //Is it a dynamic graph?
+        exportDynamic = exportDynamic && graphModel.isDynamic();
+
+        //Calculate min & max
+        normalization = NormalizationHelper.build(normalize, graph);
+
+        Progress.switchToDeterminate(progress, graph.getNodeCount() + graph.getEdgeCount());
+
+        try {
+            exportData();
+        } catch (Exception e) {
+            Logger.getLogger(ExporterGEXF.class.getName()).log(Level.SEVERE, null, e);
+        } finally {
+            graph.readUnlock();
+            Progress.finish(progress);
+        }
+
+        return !cancel;
+    }
+
+    private void exportData() {
+        GsonBuilder gsonBuilder = new GsonBuilder()
+                .registerTypeAdapter(Color.class, new ColorAdapter())
+                .registerTypeAdapterFactory(new GraphTypeAdapterFactory());
+
+        if (prettyPrint) {
+            gsonBuilder = gsonBuilder.setPrettyPrinting();
+        }
+
+        Gson gson = gsonBuilder
+                .create();
+        gson.toJson(graph, writer);
+    }
+
+    private class ColorAdapter extends WriteTypeAdapter<Color> {
+
+        @Override
+        public void write(JsonWriter out, Color value) throws IOException {
+            if (exportColors) {
+                out.name("color");
+                if (value.getAlpha() < 255) {
+                    out.value(String.format("#%08x", (value.getRGB() << 8) | value.getAlpha()));
+                } else {
+                    out.value(String.format("#%06x", value.getRGB() & 0x00FFFFFF));
+                }
+            }
+        }
+    }
+
+    private class GraphTypeAdapter extends WriteTypeAdapter<Graph> {
+
+        private final TypeAdapter<Node> nodeTypeAdapter;
+        private final TypeAdapter<Edge> edgeTypeAdapter;
+
+        public GraphTypeAdapter(Gson gson) {
+            nodeTypeAdapter = gson.getAdapter(Node.class);
+            edgeTypeAdapter = gson.getAdapter(Edge.class);
+        }
+
+        @Override
+        public void write(JsonWriter out, Graph graph) throws IOException {
+            out.beginObject();
+
+            // Attributes
+            writeAttributes(out);
+
+            // Options
+            writeOptions(out, graph);
+
+            // Nodes
+            out.name("nodes");
+            out.beginArray();
+            for (Node node : graph.getNodes()) {
+                if (!cancel) {
+                    nodeTypeAdapter.write(out, node);
+                }
+            }
+            out.endArray();
+
+            // Edges
+            out.name("edges");
+            out.beginArray();
+            for (Edge edge : graph.getEdges()) {
+                if (!cancel) {
+                    edgeTypeAdapter.write(out, edge);
+                }
+            }
+            out.endArray();
+            out.endObject();
+        }
+
+        protected void writeOptions(JsonWriter out, Graph graph) throws IOException {
+            out.name("options");
+            out.beginObject();
+            out.name("multi");
+            out.value(graph.getModel().getEdgeTypeLabels(false).length > 1);
+            out.name("allowSelfLoops");
+            out.value(true);
+            out.name("type");
+            out.value(
+                    graph.getModel().isUndirected() ? "undirected" : graph.getModel().isMixed() ? "mixed" : "directed");
+            out.endObject();
+        }
+
+        protected void writeAttributes(JsonWriter out) throws IOException {
+            if (exportMeta) {
+                out.name("attributes");
+                out.beginObject();
+                out.name("creator");
+                out.value(VersionUtils.getGephiVersion());
+                if (exportDynamic) {
+                    Configuration graphConfig = graph.getModel().getConfiguration();
+                    TimeFormat timeFormat = graph.getModel().getTimeFormat();
+                    out.name("timeformat");
+                    out.value(timeFormat.toString().toLowerCase());
+                    out.name("timerepresentation");
+                    out.value(graphConfig.getTimeRepresentation().toString().toLowerCase());
+                    out.name("timezone");
+                    out.value(graph.getModel().getTimeZone().getID());
+                }
+                out.endObject();
+            }
+        }
+    }
+
+    private class ElementTypeAdapter<T extends Element> extends WriteTypeAdapter<T> {
+
+        private final TypeAdapter<Color> colorAdapter;
+
+        public ElementTypeAdapter(Gson gson) {
+            this.colorAdapter = gson.getAdapter(Color.class);
+        }
+
+        @Override
+        public void write(JsonWriter out, T element) throws IOException {
+            throw new UnsupportedOperationException("Not to be called directly");
+        }
+
+        protected void writeAttValues(JsonWriter out, T element) throws IOException {
+            if (exportAttributes) {
+                TimeFormat timeFormat = graph.getModel().getTimeFormat();
+                DateTimeZone timeZone = graph.getModel().getTimeZone();
+
+                for (Column column : element.getAttributeColumns()) {
+                    if (!column.isProperty() ||
+                            (element instanceof Edge &&
+                                    column.getId().equals("weight"))) {
+                        // Col header, similar to spreadsheet
+                        String columnId = column.getId();
+                        String columnTitle = column.getTitle();
+                        String columnHeader =
+                                columnId.equalsIgnoreCase(columnTitle) && !column.isProperty() ? columnTitle : columnId;
+
+                        Object value = exportDynamic ? element.getAttribute(column) :
+                                element.getAttribute(column, graph.getView());
+                        out.name(columnHeader);
+                        if (value instanceof Number) {
+                            out.value((Number) value);
+                        } else if (value instanceof Boolean) {
+                            out.value((Boolean) value);
+                        } else {
+                            out.value(AttributeUtils.print(value, timeFormat, timeZone));
+                        }
+                    }
+                }
+            }
+        }
+
+        protected void writeColor(JsonWriter out, Color color) throws IOException {
+            if (exportColors) {
+                colorAdapter.write(out, color);
+            }
+        }
+
+        protected void writeLabel(JsonWriter out, T element) throws IOException {
+            if (element.getLabel() != null && !element.getLabel().isEmpty()) {
+                out.name("label");
+                out.value(element.getLabel());
+            }
+        }
+    }
+
+    private class NodeTypeAdapter extends ElementTypeAdapter<Node> {
+
+        public NodeTypeAdapter(Gson gson) {
+            super(gson);
+        }
+
+        @Override
+        public void write(JsonWriter out, Node node) throws IOException {
+            out.beginObject();
+            out.name("key");
+            out.value(node.getId().toString());
+            writeAttributes(out, node);
+            out.endObject();
+
+            Progress.progress(progress);
+        }
+
+        private void writeAttributes(JsonWriter out, Node node) throws IOException {
+            out.name("attributes");
+            out.beginObject();
+
+            // Label
+            writeLabel(out, node);
+
+            // Positions
+            writePositions(out, node);
+
+            // Size
+            writeSize(out, node);
+
+            // Colors
+            writeColor(out, node.getColor());
+
+            // Att values
+            writeAttValues(out, node);
+
+            out.endObject();
+        }
+
+        protected void writeSize(JsonWriter out, Node node) throws IOException {
+            if (exportSize) {
+                float size = normalization.normalizeSize(node.size());
+                if (normalize || size != 0) {
+                    out.name("size");
+                    out.value(size);
+                }
+            }
+        }
+
+        private void writePositions(JsonWriter out, Node node) throws IOException {
+            if (exportPosition) {
+                float x = normalization.normalizeX(node.x());
+                float y = normalization.normalizeY(node.y());
+                float z = normalization.normalizeZ(node.z());
+                if (!(x == 0 && y == 0 && z == 0)) {
+                    out.name("x");
+                    out.value(node.x());
+                    out.name("y");
+                    out.value(node.y());
+                    if (normalization.minZ != 0 || normalization.maxZ != 0) {
+                        out.name("z");
+                        out.value(node.z());
+                    }
+                }
+            }
+        }
+    }
+
+    private class EdgeTypeAdapter extends ElementTypeAdapter<Edge> {
+
+        public EdgeTypeAdapter(Gson gson) {
+            super(gson);
+        }
+
+        @Override
+        public void write(JsonWriter out, Edge edge) throws IOException {
+            out.beginObject();
+            out.name("key");
+            out.value(edge.getId().toString());
+            out.name("source");
+            out.value(edge.getSource().getId().toString());
+            out.name("target");
+            out.value(edge.getTarget().getId().toString());
+            if (!edge.isDirected() && graph.isMixed()) {
+                out.name("undirected");
+                out.value(Boolean.TRUE);
+            }
+            writeAttributes(out, edge);
+            out.endObject();
+
+            Progress.progress(progress);
+        }
+
+        private void writeAttributes(JsonWriter out, Edge edge) throws IOException {
+            out.name("attributes");
+            out.beginObject();
+
+            // Type/Kind
+            if (edge.getType() != 0) {
+                out.name("type");
+                out.value(edge.getTypeLabel().toString());
+            }
+
+            // Label
+            writeLabel(out, edge);
+
+            // Colors
+            if (edge.alpha() != 0) { //Edge has custom color
+                writeColor(out, edge.getColor());
+            }
+
+            // Att values
+            writeAttValues(out, edge);
+
+            out.endObject();
+        }
+    }
+
+    private class GraphTypeAdapterFactory implements TypeAdapterFactory {
+
+        @Override
+        public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> type) {
+            if (Node.class.isAssignableFrom(type.getRawType())) {
+                return (TypeAdapter<T>) new NodeTypeAdapter(gson);
+            } else if (Edge.class.isAssignableFrom(type.getRawType())) {
+                return (TypeAdapter<T>) new EdgeTypeAdapter(gson);
+            } else if (Graph.class.isAssignableFrom(type.getRawType())) {
+                return (TypeAdapter<T>) new GraphTypeAdapter(gson);
+            } else {
+                return null;
+            }
+        }
+    }
+
+    @Override
+    public boolean cancel() {
+        cancel = true;
+        return true;
+    }
+
+    @Override
+    public void setProgressTicket(ProgressTicket progressTicket) {
+        this.progress = progressTicket;
+    }
+
+    @Override
+    public boolean isExportVisible() {
+        return exportVisible;
+    }
+
+    @Override
+    public void setExportVisible(boolean exportVisible) {
+        this.exportVisible = exportVisible;
+    }
+
+    @Override
+    public void setWriter(Writer writer) {
+        this.writer = writer;
+    }
+
+    @Override
+    public Workspace getWorkspace() {
+        return workspace;
+    }
+
+    @Override
+    public void setWorkspace(Workspace workspace) {
+        this.workspace = workspace;
+    }
+
+    public boolean isNormalize() {
+        return normalize;
+    }
+
+    public void setNormalize(boolean normalize) {
+        this.normalize = normalize;
+    }
+
+    public boolean isExportColors() {
+        return exportColors;
+    }
+
+    public void setExportColors(boolean exportColors) {
+        this.exportColors = exportColors;
+    }
+
+    public boolean isExportPosition() {
+        return exportPosition;
+    }
+
+    public void setExportPosition(boolean exportPosition) {
+        this.exportPosition = exportPosition;
+    }
+
+    public boolean isExportSize() {
+        return exportSize;
+    }
+
+    public void setExportSize(boolean exportSize) {
+        this.exportSize = exportSize;
+    }
+
+    public boolean isExportAttributes() {
+        return exportAttributes;
+    }
+
+    public void setExportAttributes(boolean exportAttributes) {
+        this.exportAttributes = exportAttributes;
+    }
+
+    public boolean isExportDynamic() {
+        return exportDynamic;
+    }
+
+    public void setExportDynamic(boolean exportDynamic) {
+        this.exportDynamic = exportDynamic;
+    }
+
+    public boolean isExportMeta() {
+        return exportMeta;
+    }
+
+    public boolean isPrettyPrint() {
+        return prettyPrint;
+    }
+
+    public void setPrettyPrint(boolean prettyPrint) {
+        this.prettyPrint = prettyPrint;
+    }
+
+    public Format getFormat() {
+        return format;
+    }
+
+    public void setFormat(Format format) {
+        this.format = format;
+    }
+
+    public void setExportMeta(boolean exportMeta) {
+        this.exportMeta = exportMeta;
+    }
+
+    /**
+     * For convenience, the same as {@link TypeAdapter} but without the read support.
+     *
+     * @param <T> type
+     */
+    private abstract static class WriteTypeAdapter<T> extends TypeAdapter<T> {
+
+        @Override
+        public T read(JsonReader in) throws IOException {
+            throw new UnsupportedOperationException("Not supported.");
+        }
+    }
+}

modules/ExportPlugin/src/main/resources/org/gephi/io/exporter/plugin/Bundle.properties

@@ -10,3 +10,4 @@ fileType_Pajek_Name = NET Files (Pajek)
 fileType_DL_Name = DL files (UCINET)
 fileType_VNA_Name= VNA files(Netdraw)
 fileType_Spreadsheet_Name = Spreadsheet Files
+fileType_Json_Name = JSON Files
\ No newline at end of file

modules/ExportPlugin/src/test/java/org/gephi/io/exporter/plugin/JsonTest.java

+package org.gephi.io.exporter.plugin;
+
+import java.awt.*;
+import java.io.IOException;
+import org.gephi.graph.GraphGenerator;
+import org.gephi.graph.api.Graph;
+import org.gephi.graph.api.Node;
+import org.gephi.project.api.Workspace;
+import org.junit.Test;
+
+public class JsonTest {
+
+    @Test
+    public void testEmpty() throws IOException {
+        GraphGenerator graphGenerator =
+            GraphGenerator.build().withWorkspace();
+
+        Utils.assertExporterMatch("json/empty.json", createExporter(graphGenerator));
+    }
+
+    @Test
+    public void testTinyGraph() throws IOException {
+        GraphGenerator graphGenerator =
+            GraphGenerator.build().withWorkspace().generateTinyGraph();
+
+        Utils.assertExporterMatch("json/tiny.json", createExporter(graphGenerator));
+    }
+
+    @Test
+    public void testNodeColumn() throws IOException {
+        GraphGenerator graphGenerator =
+            GraphGenerator.build().withWorkspace().generateTinyGraph().addDoubleNodeColumn();
+
+        Utils.assertExporterMatch("json/column.json", createExporter(graphGenerator));
+    }
+
+    @Test
+    public void testLabels() throws IOException {
+        GraphGenerator graphGenerator =
+            GraphGenerator.build().withWorkspace().generateTinyGraph().addNodeLabels().addEdgeLabels();
+
+        Utils.assertExporterMatch("json/labels.json", createExporter(graphGenerator));
+    }
+
+    @Test
+    public void testMulti() throws IOException {
+        GraphGenerator graphGenerator =
+            GraphGenerator.build().withWorkspace().generateTinyMultiGraph();
+
+        Utils.assertExporterMatch("json/multi.json", createExporter(graphGenerator));
+    }
+
+    @Test
+    public void testUndirected() throws IOException {
+        GraphGenerator graphGenerator =
+            GraphGenerator.build().withWorkspace().generateTinyUndirectedGraph();
+
+        Utils.assertExporterMatch("json/undirected.json", createExporter(graphGenerator));
+    }
+
+    @Test
+    public void testMixed() throws IOException {
+        GraphGenerator graphGenerator =
+            GraphGenerator.build().withWorkspace().generateTinyMixedGraph();
+
+        Utils.assertExporterMatch("json/mixed.json", createExporter(graphGenerator));
+    }
+
+    @Test
+    public void testColors() throws IOException {
+        GraphGenerator graphGenerator =
+                GraphGenerator.build().withWorkspace().generateTinyGraph();
+        Graph graph = graphGenerator.getGraph();
+        Node n1 = graph.getNode(GraphGenerator.FIRST_NODE);
+        Node n2 = graph.getNode(GraphGenerator.SECOND_NODE);
+        n1.setColor(Color.CYAN);
+        n2.setColor(new Color(255, 100, 120, 254));
+
+        ExporterJson exporterJson = createExporter(graphGenerator);
+        exporterJson.setExportColors(true);
+        Utils.assertExporterMatch("json/colors.json", exporterJson);
+    }
+
+    private static ExporterJson createExporter(GraphGenerator graphGenerator) {
+        Workspace workspace = graphGenerator.getWorkspace();
+        ExporterJson exporterJson = new ExporterJson();
+        exporterJson.setWorkspace(workspace);
+        exporterJson.setExportMeta(false);
+        exporterJson.setExportColors(false);
+        exporterJson.setExportPosition(false);
+        exporterJson.setExportSize(false);
+        return exporterJson;
+    }
+}

modules/ExportPlugin/src/test/java/org/gephi/io/exporter/plugin/Utils.java

@@ -11,6 +11,14 @@ import org.xmlunit.diff.Difference;
 
 public class Utils {
 
+    public static void print(CharacterExporter exporter) throws IOException {
+        StringWriter writer = new StringWriter();
+        exporter.setWriter(writer);
+        exporter.execute();
+        writer.close();
+        System.out.println(writer);
+    }
+
     public static void assertExporterMatch(String expectedFilename, CharacterExporter exporter) throws IOException {
         String expected = getResourceContent(expectedFilename);
         StringWriter writer = new StringWriter();

modules/ExportPlugin/src/test/resources/org/gephi/io/exporter/plugin/json/colors.json

+{
+  "options": {
+    "multi": false,
+    "allowSelfLoops": true,
+    "type": "directed"
+  },
+  "nodes": [
+    {
+      "key": "1",
+      "attributes": {
+        "color": "#00ffff"
+      }
+    },
+    {
+      "key": "2",
+      "attributes": {
+        "color": "#ff6478fe"
+      }
+    }
+  ],
+  "edges": [
+    {
+      "key": "1",
+      "source": "1",
+      "target": "2",
+      "attributes": {
+        "color": "#000000",
+        "weight": 1.0
+      }
+    }
+  ]
+}
\ No newline at end of file

modules/ExportPlugin/src/test/resources/org/gephi/io/exporter/plugin/json/column.json

+{
+  "options": {
+    "multi": false,
+    "allowSelfLoops": true,
+    "type": "directed"
+  },
+  "nodes": [
+    {
+      "key": "1",
+      "attributes": {
+        "value": 10.0
+      }
+    },
+    {
+      "key": "2",
+      "attributes": {
+        "value": 11.0
+      }
+    }
+  ],
+  "edges": [
+    {
+      "key": "1",
+      "source": "1",
+      "target": "2",
+      "attributes": {
+        "weight": 1.0
+      }
+    }
+  ]
+}
\ No newline at end of file

modules/ExportPlugin/src/test/resources/org/gephi/io/exporter/plugin/json/empty.json

+{
+  "options": {
+    "multi": false,
+    "allowSelfLoops": true,
+    "type": "directed"
+  },
+  "nodes": [],
+  "edges": []
+}
\ No newline at end of file

modules/ExportPlugin/src/test/resources/org/gephi/io/exporter/plugin/json/labels.json

+{
+  "options": {
+    "multi": false,
+    "allowSelfLoops": true,
+    "type": "directed"
+  },
+  "nodes": [
+    {
+      "key": "1",
+      "attributes": {
+        "label": "1"
+      }
+    },
+    {
+      "key": "2",
+      "attributes": {
+        "label": "2"
+      }
+    }
+  ],
+  "edges": [
+    {
+      "key": "1",
+      "source": "1",
+      "target": "2",
+      "attributes": {
+        "label": "1",
+        "weight": 1.0
+      }
+    }
+  ]
+}
\ No newline at end of file

modules/ExportPlugin/src/test/resources/org/gephi/io/exporter/plugin/json/mixed.json

+{
+  "options": {
+    "multi": false,
+    "allowSelfLoops": true,
+    "type": "mixed"
+  },
+  "nodes": [
+    {
+      "key": "1",
+      "attributes": {}
+    },
+    {
+      "key": "2",
+      "attributes": {}
+    },
+    {
+      "key": "3",
+      "attributes": {}
+    }
+  ],
+  "edges": [
+    {
+      "key": "1",
+      "source": "1",
+      "target": "2",
+      "undirected": true,
+      "attributes": {
+        "weight": 1.0
+      }
+    },
+    {
+      "key": "2",
+      "source": "1",
+      "target": "3",
+      "attributes": {
+        "weight": 1.0
+      }
+    }
+  ]
+}
\ No newline at end of file

modules/ExportPlugin/src/test/resources/org/gephi/io/exporter/plugin/json/multi.json

+{
+  "options": {
+    "multi": true,
+    "allowSelfLoops": true,
+    "type": "directed"
+  },
+  "nodes": [
+    {
+      "key": "1",
+      "attributes": {}
+    },
+    {
+      "key": "2",
+      "attributes": {}
+    }
+  ],
+  "edges": [
+    {
+      "key": "1",
+      "source": "1",
+      "target": "2",
+      "attributes": {
+        "weight": 1.0
+      }
+    },
+    {
+      "key": "2",
+      "source": "1",
+      "target": "2",
+      "attributes": {
+        "type": "1",
+        "weight": 1.0
+      }
+    }
+  ]
+}
\ No newline at end of file

modules/ExportPlugin/src/test/resources/org/gephi/io/exporter/plugin/json/tiny.json

+{
+  "options": {
+    "multi": false,
+    "allowSelfLoops": true,
+    "type": "directed"
+  },
+  "nodes": [
+    {
+      "key": "1",
+      "attributes": {}
+    },
+    {
+      "key": "2",
+      "attributes": {}
+    }
+  ],
+  "edges": [
+    {
+      "key": "1",
+      "source": "1",
+      "target": "2",
+      "attributes": {
+        "weight": 1.0
+      }
+    }
+  ]
+}
\ No newline at end of file

modules/ExportPlugin/src/test/resources/org/gephi/io/exporter/plugin/json/undirected.json

+{
+  "options": {
+    "multi": false,
+    "allowSelfLoops": true,
+    "type": "undirected"
+  },
+  "nodes": [
+    {
+      "key": "1",
+      "attributes": {}
+    },
+    {
+      "key": "2",
+      "attributes": {}
+    }
+  ],
+  "edges": [
+    {
+      "key": "1",
+      "source": "1",
+      "target": "2",
+      "attributes": {
+        "weight": 1.0
+      }
+    }
+  ]
+}
\ No newline at end of file

modules/ExportPluginUI/src/main/java/org/gephi/ui/exporter/plugin/UIExporterJson.java

+/*
+Copyright 2008-2010 Gephi
+Authors : Mathieu Bastian <mathieu.bastian@gephi.org>
+Website : http://www.gephi.org
+
+This file is part of Gephi.
+
+DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+
+Copyright 2011 Gephi Consortium. All rights reserved.
+
+The contents of this file are subject to the terms of either the GNU
+General Public License Version 3 only ("GPL") or the Common
+Development and Distribution License("CDDL") (collectively, the
+"License"). You may not use this file except in compliance with the
+License. You can obtain a copy of the License at
+http://gephi.org/about/legal/license-notice/
+or /cddl-1.0.txt and /gpl-3.0.txt. See the License for the
+specific language governing permissions and limitations under the
+License.  When distributing the software, include this License Header
+Notice in each file and include the License files at
+/cddl-1.0.txt and /gpl-3.0.txt. If applicable, add the following below the
+License Header, with the fields enclosed by brackets [] replaced by
+your own identifying information:
+"Portions Copyrighted [year] [name of copyright owner]"
+
+If you wish your version of this file to be governed by only the CDDL
+or only the GPL Version 3, indicate your decision by adding
+"[Contributor] elects to include this software in this distribution
+under the [CDDL or GPL Version 3] license." If you do not indicate a
+single choice of license, a recipient has the option to distribute
+your version of this file under either the CDDL, the GPL Version 3 or
+to extend the choice of license to its licensees as provided above.
+However, if you add GPL Version 3 code and therefore, elected the GPL
+Version 3 license, then the option applies only if the new code is
+made subject to such option by the copyright holder.
+
+Contributor(s):
+
+Portions Copyrighted 2011 Gephi Consortium.
+ */
+
+package org.gephi.ui.exporter.plugin;
+
+import javax.swing.JPanel;
+import org.gephi.io.exporter.plugin.ExporterJson;
+import org.gephi.io.exporter.spi.Exporter;
+import org.gephi.io.exporter.spi.ExporterUI;
+import org.openide.util.NbBundle;
+import org.openide.util.lookup.ServiceProvider;
+
+/**
+ * @author Mathieu Bastian
+ */
+@ServiceProvider(service = ExporterUI.class)
+public class UIExporterJson implements ExporterUI {
+
+    private final ExporterJsonSettings settings = new ExporterJsonSettings();
+    private UIExporterJsonPanel panel;
+    private ExporterJson exporterJson;
+
+    @Override
+    public void setup(Exporter exporter) {
+        exporterJson = (ExporterJson) exporter;
+        settings.load(exporterJson);
+        if (panel != null) {
+            panel.setup(exporterJson);
+        }
+    }
+
+    @Override
+    public void unsetup(boolean update) {
+        if (update) {
+            panel.unsetup(exporterJson);
+            settings.save(exporterJson);
+        }
+        panel = null;
+        exporterJson = null;
+    }
+
+    @Override
+    public JPanel getPanel() {
+        panel = new UIExporterJsonPanel();
+        return panel;
+    }
+
+    @Override
+    public boolean isUIForExporter(Exporter exporter) {
+        return exporter instanceof ExporterJson;
+    }
+
+    @Override
+    public String getDisplayName() {
+        return NbBundle.getMessage(UIExporterJson.class, "UIExporterJson.name");
+    }
+
+    private static class ExporterJsonSettings extends AbstractExporterSettings {
+
+        // Preference names
+        private final static String NORMALIZE = "Json_normalize";
+        private final static String EXPORT_COLORS = "Json_exportColors";
+        private final static String EXPORT_POSITION = "Json_exportPosition";
+        private final static String EXPORT_ATTRIBUTES = "Json_exportAttributes";
+        private final static String EXPORT_SIZE = "Json_exportSize";
+        private final static String EXPORT_DYNAMICS = "Json_exportDynamics";
+        private final static String EXPORT_META = "Json_exportMeta";
+        private final static String PRETTY_PRINT = "Json_prettyPrint";
+        private final static String FORMAT = "Json_format";
+        // Default
+        private final static ExporterJson DEFAULT = new ExporterJson();
+
+        private void save(ExporterJson exporterJson) {
+            put(NORMALIZE, exporterJson.isNormalize());
+            put(EXPORT_COLORS, exporterJson.isExportColors());
+            put(EXPORT_POSITION, exporterJson.isExportPosition());
+            put(EXPORT_SIZE, exporterJson.isExportSize());
+            put(EXPORT_ATTRIBUTES, exporterJson.isExportAttributes());
+            put(EXPORT_DYNAMICS, exporterJson.isExportDynamic());
+            put(EXPORT_META, exporterJson.isExportMeta());
+            put(FORMAT, exporterJson.getFormat().name());
+            put(PRETTY_PRINT, exporterJson.isPrettyPrint());
+        }
+
+        private void load(ExporterJson exporterJson) {
+            exporterJson.setNormalize(get(NORMALIZE, DEFAULT.isNormalize()));
+            exporterJson.setExportColors(get(EXPORT_COLORS, DEFAULT.isExportColors()));
+            exporterJson.setExportAttributes(get(EXPORT_ATTRIBUTES, DEFAULT.isExportAttributes()));
+            exporterJson.setExportPosition(get(EXPORT_POSITION, DEFAULT.isExportPosition()));
+            exporterJson.setExportSize(get(EXPORT_SIZE, DEFAULT.isExportSize()));
+            exporterJson.setExportDynamic(get(EXPORT_DYNAMICS, DEFAULT.isExportDynamic()));
+            exporterJson.setExportMeta(get(EXPORT_META, DEFAULT.isExportMeta()));
+            exporterJson.setFormat(ExporterJson.Format.valueOf(get(FORMAT, DEFAULT.getFormat().name())));
+            exporterJson.setPrettyPrint(get(PRETTY_PRINT, DEFAULT.isPrettyPrint()));
+        }
+    }
+}

modules/ExportPluginUI/src/main/java/org/gephi/ui/exporter/plugin/UIExporterJsonPanel.form

+<?xml version="1.0" encoding="UTF-8" ?>
+
+<Form version="1.5" maxVersion="1.7" type="org.netbeans.modules.form.forminfo.JPanelFormInfo">
+  <AuxValues>
+    <AuxValue name="FormSettings_autoResourcing" type="java.lang.Integer" value="1"/>
+    <AuxValue name="FormSettings_autoSetComponentName" type="java.lang.Boolean" value="false"/>
+    <AuxValue name="FormSettings_generateFQN" type="java.lang.Boolean" value="true"/>
+    <AuxValue name="FormSettings_generateMnemonicsCode" type="java.lang.Boolean" value="false"/>
+    <AuxValue name="FormSettings_i18nAutoMode" type="java.lang.Boolean" value="true"/>
+    <AuxValue name="FormSettings_layoutCodeTarget" type="java.lang.Integer" value="1"/>
+    <AuxValue name="FormSettings_listenerGenerationStyle" type="java.lang.Integer" value="0"/>
+    <AuxValue name="FormSettings_variablesLocal" type="java.lang.Boolean" value="false"/>
+    <AuxValue name="FormSettings_variablesModifier" type="java.lang.Integer" value="2"/>
+  </AuxValues>
+
+  <Layout>
+    <DimensionLayout dim="0">
+      <Group type="103" groupAlignment="0" attributes="0">
+          <Group type="102" attributes="0">
+              <EmptySpace max="-2" attributes="0"/>
+              <Group type="103" groupAlignment="0" attributes="0">
+                  <Group type="102" alignment="0" attributes="0">
+                      <Component id="normalizeCheckbox" min="-2" max="-2" attributes="0"/>
+                      <EmptySpace type="unrelated" max="-2" attributes="0"/>
+                      <Component id="labelNormalize" pref="225" max="32767" attributes="0"/>
+                  </Group>
+                  <Group type="102" attributes="0">
+                      <Group type="103" groupAlignment="0" attributes="0">
+                          <Group type="102" alignment="0" attributes="0">
+                              <Component id="labelExport" min="-2" max="-2" attributes="0"/>
+                              <EmptySpace type="separate" max="-2" attributes="0"/>
+                              <Group type="103" groupAlignment="0" attributes="0">
+                                  <Component id="attributesExportCheckbox" alignment="0" min="-2" max="-2" attributes="0"/>
+                                  <Component id="sizeExportCheckbox" alignment="0" min="-2" max="-2" attributes="0"/>
+                                  <Component id="colorsExportCheckbox" alignment="0" min="-2" max="-2" attributes="0"/>
+                                  <Component id="positionExportCheckbox" alignment="0" min="-2" max="-2" attributes="0"/>
+                                  <Component id="dynamicExportCheckbox" alignment="0" min="-2" max="-2" attributes="0"/>
+                              </Group>
+                          </Group>
+                          <Component id="prettyPrintCheckbox" alignment="0" min="-2" max="-2" attributes="0"/>
+                          <Group type="102" alignment="0" attributes="0">
+                              <Component id="labelFormat" min="-2" max="-2" attributes="0"/>
+                              <EmptySpace type="separate" max="-2" attributes="0"/>
+                              <Component id="formatCombo" min="-2" pref="177" max="-2" attributes="0"/>
+                          </Group>
+                      </Group>
+                      <EmptySpace min="0" pref="0" max="32767" attributes="0"/>
+                  </Group>
+              </Group>
+              <EmptySpace max="-2" attributes="0"/>
+          </Group>
+      </Group>
+    </DimensionLayout>
+    <DimensionLayout dim="1">
+      <Group type="103" groupAlignment="0" attributes="0">
+          <Group type="102" alignment="1" attributes="0">
+              <EmptySpace max="-2" attributes="0"/>
+              <Group type="103" groupAlignment="3" attributes="0">
+                  <Component id="labelFormat" alignment="3" min="-2" max="-2" attributes="0"/>
+                  <Component id="formatCombo" alignment="3" min="-2" max="-2" attributes="0"/>
+              </Group>
+              <EmptySpace pref="13" max="32767" attributes="0"/>
+              <Group type="103" groupAlignment="3" attributes="0">
+                  <Component id="labelExport" alignment="3" min="-2" max="-2" attributes="0"/>
+                  <Component id="positionExportCheckbox" alignment="3" min="-2" max="-2" attributes="0"/>
+              </Group>
+              <EmptySpace type="unrelated" max="-2" attributes="0"/>
+              <Component id="colorsExportCheckbox" min="-2" max="-2" attributes="0"/>
+              <EmptySpace type="unrelated" max="-2" attributes="0"/>
+              <Component id="sizeExportCheckbox" min="-2" max="-2" attributes="0"/>
+              <EmptySpace type="unrelated" max="-2" attributes="0"/>
+              <Component id="attributesExportCheckbox" min="-2" max="-2" attributes="0"/>
+              <EmptySpace type="unrelated" max="-2" attributes="0"/>
+              <Component id="dynamicExportCheckbox" min="-2" max="-2" attributes="0"/>
+              <EmptySpace type="unrelated" max="-2" attributes="0"/>
+              <Group type="103" groupAlignment="3" attributes="0">
+                  <Component id="normalizeCheckbox" alignment="3" min="-2" max="-2" attributes="0"/>
+                  <Component id="labelNormalize" alignment="3" min="-2" max="-2" attributes="0"/>
+              </Group>
+              <EmptySpace max="-2" attributes="0"/>
+              <Component id="prettyPrintCheckbox" min="-2" max="-2" attributes="0"/>
+              <EmptySpace min="-2" pref="15" max="-2" attributes="0"/>
+          </Group>
+      </Group>
+    </DimensionLayout>
+  </Layout>
+  <SubComponents>
+    <Component class="javax.swing.JLabel" name="labelExport">
+      <Properties>
+        <Property name="text" type="java.lang.String" editor="org.netbeans.modules.i18n.form.FormI18nStringEditor">
+          <ResourceString bundle="org/gephi/ui/exporter/plugin/Bundle.properties" key="UIExporterJsonPanel.labelExport.text" replaceFormat="org.openide.util.NbBundle.getMessage({sourceFileName}.class, &quot;{key}&quot;)"/>
+        </Property>
+      </Properties>
+    </Component>
+    <Component class="javax.swing.JCheckBox" name="positionExportCheckbox">
+      <Properties>
+        <Property name="text" type="java.lang.String" editor="org.netbeans.modules.i18n.form.FormI18nStringEditor">
+          <ResourceString bundle="org/gephi/ui/exporter/plugin/Bundle.properties" key="UIExporterJsonPanel.positionExportCheckbox.text" replaceFormat="org.openide.util.NbBundle.getMessage({sourceFileName}.class, &quot;{key}&quot;)"/>
+        </Property>
+      </Properties>
+    </Component>
+    <Component class="javax.swing.JCheckBox" name="colorsExportCheckbox">
+      <Properties>
+        <Property name="text" type="java.lang.String" editor="org.netbeans.modules.i18n.form.FormI18nStringEditor">
+          <ResourceString bundle="org/gephi/ui/exporter/plugin/Bundle.properties" key="UIExporterJsonPanel.colorsExportCheckbox.text" replaceFormat="org.openide.util.NbBundle.getMessage({sourceFileName}.class, &quot;{key}&quot;)"/>
+        </Property>
+      </Properties>
+    </Component>
+    <Component class="javax.swing.JCheckBox" name="attributesExportCheckbox">
+      <Properties>
+        <Property name="text" type="java.lang.String" editor="org.netbeans.modules.i18n.form.FormI18nStringEditor">
+          <ResourceString bundle="org/gephi/ui/exporter/plugin/Bundle.properties" key="UIExporterJsonPanel.attributesExportCheckbox.text" replaceFormat="org.openide.util.NbBundle.getMessage({sourceFileName}.class, &quot;{key}&quot;)"/>
+        </Property>
+      </Properties>
+    </Component>
+    <Component class="javax.swing.JCheckBox" name="sizeExportCheckbox">
+      <Properties>
+        <Property name="text" type="java.lang.String" editor="org.netbeans.modules.i18n.form.FormI18nStringEditor">
+          <ResourceString bundle="org/gephi/ui/exporter/plugin/Bundle.properties" key="UIExporterJsonPanel.sizeExportCheckbox.text" replaceFormat="org.openide.util.NbBundle.getMessage({sourceFileName}.class, &quot;{key}&quot;)"/>
+        </Property>
+      </Properties>
+    </Component>
+    <Component class="javax.swing.JLabel" name="labelNormalize">
+      <Properties>
+        <Property name="font" type="java.awt.Font" editor="org.netbeans.beaninfo.editors.FontEditor">
+          <Font name="Tahoma" size="10" style="0"/>
+        </Property>
+        <Property name="foreground" type="java.awt.Color" editor="org.netbeans.beaninfo.editors.ColorEditor">
+          <Color blue="66" green="66" red="66" type="rgb"/>
+        </Property>
+        <Property name="text" type="java.lang.String" editor="org.netbeans.modules.i18n.form.FormI18nStringEditor">
+          <ResourceString bundle="org/gephi/ui/exporter/plugin/Bundle.properties" key="UIExporterJsonPanel.labelNormalize.text" replaceFormat="org.openide.util.NbBundle.getMessage({sourceFileName}.class, &quot;{key}&quot;)"/>
+        </Property>
+      </Properties>
+    </Component>
+    <Component class="javax.swing.JCheckBox" name="normalizeCheckbox">
+      <Properties>
+        <Property name="text" type="java.lang.String" editor="org.netbeans.modules.i18n.form.FormI18nStringEditor">
+          <ResourceString bundle="org/gephi/ui/exporter/plugin/Bundle.properties" key="UIExporterJsonPanel.normalizeCheckbox.text" replaceFormat="org.openide.util.NbBundle.getMessage({sourceFileName}.class, &quot;{key}&quot;)"/>
+        </Property>
+      </Properties>
+    </Component>
+    <Component class="javax.swing.JCheckBox" name="dynamicExportCheckbox">
+      <Properties>
+        <Property name="text" type="java.lang.String" editor="org.netbeans.modules.i18n.form.FormI18nStringEditor">
+          <ResourceString bundle="org/gephi/ui/exporter/plugin/Bundle.properties" key="UIExporterJsonPanel.dynamicExportCheckbox.text" replaceFormat="org.openide.util.NbBundle.getMessage({sourceFileName}.class, &quot;{key}&quot;)"/>
+        </Property>
+      </Properties>
+    </Component>
+    <Component class="javax.swing.JCheckBox" name="prettyPrintCheckbox">
+      <Properties>
+        <Property name="text" type="java.lang.String" editor="org.netbeans.modules.i18n.form.FormI18nStringEditor">
+          <ResourceString bundle="org/gephi/ui/exporter/plugin/Bundle.properties" key="UIExporterJsonPanel.prettyPrintCheckbox.text" replaceFormat="org.openide.util.NbBundle.getMessage({sourceFileName}.class, &quot;{key}&quot;)"/>
+        </Property>
+      </Properties>
+    </Component>
+    <Component class="javax.swing.JLabel" name="labelFormat">
+      <Properties>
+        <Property name="text" type="java.lang.String" editor="org.netbeans.modules.i18n.form.FormI18nStringEditor">
+          <ResourceString bundle="org/gephi/ui/exporter/plugin/Bundle.properties" key="UIExporterJsonPanel.labelFormat.text" replaceFormat="org.openide.util.NbBundle.getMessage({sourceFileName}.class, &quot;{key}&quot;)"/>
+        </Property>
+      </Properties>
+    </Component>
+    <Component class="javax.swing.JComboBox" name="formatCombo">
+      <AuxValues>
+        <AuxValue name="JavaCodeGenerator_TypeParameters" type="java.lang.String" value="&lt;ExporterJson.Format&gt;"/>
+      </AuxValues>
+    </Component>
+  </SubComponents>
+</Form>

modules/ExportPluginUI/src/main/java/org/gephi/ui/exporter/plugin/UIExporterJsonPanel.java

+/*
+ Copyright 2008-2010 Gephi
+ Authors : Mathieu Bastian <mathieu.bastian@gephi.org>
+ Website : http://www.gephi.org
+
+ This file is part of Gephi.
+
+ DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+
+ Copyright 2011 Gephi Consortium. All rights reserved.
+
+ The contents of this file are subject to the terms of either the GNU
+ General Public License Version 3 only ("GPL") or the Common
+ Development and Distribution License("CDDL") (collectively, the
+ "License"). You may not use this file except in compliance with the
+ License. You can obtain a copy of the License at
+ http://gephi.org/about/legal/license-notice/
+ or /cddl-1.0.txt and /gpl-3.0.txt. See the License for the
+ specific language governing permissions and limitations under the
+ License.  When distributing the software, include this License Header
+ Notice in each file and include the License files at
+ /cddl-1.0.txt and /gpl-3.0.txt. If applicable, add the following below the
+ License Header, with the fields enclosed by brackets [] replaced by
+ your own identifying information:
+ "Portions Copyrighted [year] [name of copyright owner]"
+
+ If you wish your version of this file to be governed by only the CDDL
+ or only the GPL Version 3, indicate your decision by adding
+ "[Contributor] elects to include this software in this distribution
+ under the [CDDL or GPL Version 3] license." If you do not indicate a
+ single choice of license, a recipient has the option to distribute
+ your version of this file under either the CDDL, the GPL Version 3 or
+ to extend the choice of license to its licensees as provided above.
+ However, if you add GPL Version 3 code and therefore, elected the GPL
+ Version 3 license, then the option applies only if the new code is
+ made subject to such option by the copyright holder.
+
+ Contributor(s):
+
+ Portions Copyrighted 2011 Gephi Consortium.
+ */
+
+package org.gephi.ui.exporter.plugin;
+
+import javax.swing.DefaultComboBoxModel;
+import org.gephi.io.exporter.plugin.ExporterJson;
+
+/**
+ * @author Mathieu Bastian
+ */
+public class UIExporterJsonPanel extends javax.swing.JPanel {
+
+    // Variables declaration - do not modify//GEN-BEGIN:variables
+    private javax.swing.JCheckBox attributesExportCheckbox;
+    private javax.swing.JCheckBox colorsExportCheckbox;
+    private javax.swing.JCheckBox dynamicExportCheckbox;
+    private javax.swing.JComboBox<ExporterJson.Format> formatCombo;
+    private javax.swing.JLabel labelExport;
+    private javax.swing.JLabel labelFormat;
+    private javax.swing.JLabel labelNormalize;
+    private javax.swing.JCheckBox normalizeCheckbox;
+    private javax.swing.JCheckBox positionExportCheckbox;
+    private javax.swing.JCheckBox prettyPrintCheckbox;
+    private javax.swing.JCheckBox sizeExportCheckbox;
+    // End of variables declaration//GEN-END:variables
+
+    public UIExporterJsonPanel() {
+        initComponents();
+
+        // Init format combo
+        DefaultComboBoxModel<ExporterJson.Format> comboBoxModel =
+            new DefaultComboBoxModel<>(ExporterJson.Format.values());
+        formatCombo.setModel(comboBoxModel);
+    }
+
+    public void setup(ExporterJson exporterJson) {
+        formatCombo.setSelectedItem(exporterJson.getFormat());
+        colorsExportCheckbox.setSelected(exporterJson.isExportColors());
+        positionExportCheckbox.setSelected(exporterJson.isExportPosition());
+        sizeExportCheckbox.setSelected(exporterJson.isExportSize());
+        attributesExportCheckbox.setSelected(exporterJson.isExportAttributes());
+        normalizeCheckbox.setSelected(exporterJson.isNormalize());
+        dynamicExportCheckbox.setSelected(exporterJson.isExportDynamic());
+        prettyPrintCheckbox.setSelected(exporterJson.isPrettyPrint());
+    }
+
+    public void unsetup(ExporterJson exporterJson) {
+        exporterJson.setFormat((ExporterJson.Format) formatCombo.getSelectedItem());
+        exporterJson.setExportAttributes(attributesExportCheckbox.isSelected());
+        exporterJson.setExportColors(colorsExportCheckbox.isSelected());
+        exporterJson.setExportSize(sizeExportCheckbox.isSelected());
+        exporterJson.setExportPosition(positionExportCheckbox.isSelected());
+        exporterJson.setNormalize(normalizeCheckbox.isSelected());
+        exporterJson.setExportDynamic(dynamicExportCheckbox.isSelected());
+        exporterJson.setPrettyPrint(prettyPrintCheckbox.isSelected());
+    }
+
+    /**
+     * This method is called from within the constructor to initialize the form.
+     * WARNING: Do NOT modify this code. The content of this method is always
+     * regenerated by the Form Editor.
+     */
+    @SuppressWarnings("unchecked")
+    // <editor-fold defaultstate="collapsed" desc="Generated Code">//GEN-BEGIN:initComponents
+    private void initComponents() {
+
+        labelExport = new javax.swing.JLabel();
+        positionExportCheckbox = new javax.swing.JCheckBox();
+        colorsExportCheckbox = new javax.swing.JCheckBox();
+        attributesExportCheckbox = new javax.swing.JCheckBox();
+        sizeExportCheckbox = new javax.swing.JCheckBox();
+        labelNormalize = new javax.swing.JLabel();
+        normalizeCheckbox = new javax.swing.JCheckBox();
+        dynamicExportCheckbox = new javax.swing.JCheckBox();
+        prettyPrintCheckbox = new javax.swing.JCheckBox();
+        labelFormat = new javax.swing.JLabel();
+        formatCombo = new javax.swing.JComboBox<>();
+
+        labelExport.setText(org.openide.util.NbBundle.getMessage(UIExporterJsonPanel.class, "UIExporterJsonPanel.labelExport.text")); // NOI18N
+
+        positionExportCheckbox.setText(org.openide.util.NbBundle.getMessage(UIExporterJsonPanel.class, "UIExporterJsonPanel.positionExportCheckbox.text")); // NOI18N
+
+        colorsExportCheckbox.setText(org.openide.util.NbBundle.getMessage(UIExporterJsonPanel.class, "UIExporterJsonPanel.colorsExportCheckbox.text")); // NOI18N
+
+        attributesExportCheckbox.setText(org.openide.util.NbBundle.getMessage(UIExporterJsonPanel.class, "UIExporterJsonPanel.attributesExportCheckbox.text")); // NOI18N
+
+        sizeExportCheckbox.setText(org.openide.util.NbBundle.getMessage(UIExporterJsonPanel.class, "UIExporterJsonPanel.sizeExportCheckbox.text")); // NOI18N
+
+        labelNormalize.setFont(new java.awt.Font("Tahoma", 0, 10)); // NOI18N
+        labelNormalize.setForeground(new java.awt.Color(102, 102, 102));
+        labelNormalize.setText(org.openide.util.NbBundle.getMessage(UIExporterJsonPanel.class, "UIExporterJsonPanel.labelNormalize.text")); // NOI18N
+
+        normalizeCheckbox.setText(org.openide.util.NbBundle.getMessage(UIExporterJsonPanel.class, "UIExporterJsonPanel.normalizeCheckbox.text")); // NOI18N
+
+        dynamicExportCheckbox.setText(org.openide.util.NbBundle.getMessage(UIExporterJsonPanel.class, "UIExporterJsonPanel.dynamicExportCheckbox.text")); // NOI18N
+
+        prettyPrintCheckbox.setText(org.openide.util.NbBundle.getMessage(UIExporterJsonPanel.class, "UIExporterJsonPanel.prettyPrintCheckbox.text")); // NOI18N
+
+        labelFormat.setText(org.openide.util.NbBundle.getMessage(UIExporterJsonPanel.class, "UIExporterJsonPanel.labelFormat.text")); // NOI18N
+
+        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
+        this.setLayout(layout);
+        layout.setHorizontalGroup(
+            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
+            .addGroup(layout.createSequentialGroup()
+                .addContainerGap()
+                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
+                    .addGroup(layout.createSequentialGroup()
+                        .addComponent(normalizeCheckbox)
+                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
+                        .addComponent(labelNormalize, javax.swing.GroupLayout.DEFAULT_SIZE, 225, Short.MAX_VALUE))
+                    .addGroup(layout.createSequentialGroup()
+                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
+                            .addGroup(layout.createSequentialGroup()
+                                .addComponent(labelExport)
+                                .addGap(18, 18, 18)
+                                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
+                                    .addComponent(attributesExportCheckbox)
+                                    .addComponent(sizeExportCheckbox)
+                                    .addComponent(colorsExportCheckbox)
+                                    .addComponent(positionExportCheckbox)
+                                    .addComponent(dynamicExportCheckbox)))
+                            .addComponent(prettyPrintCheckbox)
+                            .addGroup(layout.createSequentialGroup()
+                                .addComponent(labelFormat)
+                                .addGap(18, 18, 18)
+                                .addComponent(formatCombo, javax.swing.GroupLayout.PREFERRED_SIZE, 177, javax.swing.GroupLayout.PREFERRED_SIZE)))
+                        .addGap(0, 0, Short.MAX_VALUE)))
+                .addContainerGap())
+        );
+        layout.setVerticalGroup(
+            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
+            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
+                .addContainerGap()
+                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
+                    .addComponent(labelFormat)
+                    .addComponent(formatCombo, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
+                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 13, Short.MAX_VALUE)
+                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
+                    .addComponent(labelExport)
+                    .addComponent(positionExportCheckbox))
+                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
+                .addComponent(colorsExportCheckbox)
+                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
+                .addComponent(sizeExportCheckbox)
+                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
+                .addComponent(attributesExportCheckbox)
+                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
+                .addComponent(dynamicExportCheckbox)
+                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
+                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
+                    .addComponent(normalizeCheckbox)
+                    .addComponent(labelNormalize))
+                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
+                .addComponent(prettyPrintCheckbox)
+                .addGap(15, 15, 15))
+        );
+    }// </editor-fold>//GEN-END:initComponents
+}

modules/ExportPluginUI/src/main/resources/org/gephi/ui/exporter/plugin/Bundle.properties

@@ -9,6 +9,7 @@ UIExporterPajek.name = Pajek
 UIExporterDL.name = DL
 UIExporterVNA.name = VNA
 UIExporterSpreadsheetPanel.name = Spreadsheet
+UIExporterJson.name = Json
 
 UIExporterGDFPanel.jRadioButton1.text=Simple quotes
 UIExporterGDFPanel.positionExportCheckbox.text=Position (x,y)
@@ -83,3 +84,14 @@ UIExporterSpreadsheetPanel.normalizeCheckbox.text=Normalize
 UIExporterSpreadsheetPanel.labelNormalize.text=Scale position and size between 0 and 1
 UIExporterSpreadsheetPanel.labelExport.text=Export:
 UIExporterGEXFPanel.includeAttValuesNullCheckbox.text=Include null attribute values
+
+UIExporterJsonPanel.normalizeCheckbox.text=Normalize
+UIExporterJsonPanel.labelNormalize.text=Scale position and size between 0 and 1
+UIExporterJsonPanel.sizeExportCheckbox.text=Size
+UIExporterJsonPanel.attributesExportCheckbox.text=Attributes
+UIExporterJsonPanel.colorsExportCheckbox.text=Colors
+UIExporterJsonPanel.positionExportCheckbox.text=Position (x,y,z)
+UIExporterJsonPanel.labelExport.text=Export:
+UIExporterJsonPanel.dynamicExportCheckbox.text=Dynamic
+UIExporterJsonPanel.prettyPrintCheckbox.text=Pretty print
+UIExporterJsonPanel.labelFormat.text=Format:

modules/GraphAPI/src/test/java/org/gephi/graph/GraphGenerator.java

@@ -30,6 +30,7 @@ public class GraphGenerator {
     public static final String INTERVAL_DOUBLE_COLUMN = "price";
     public static final String FIRST_NODE = "1";
     public static final String SECOND_NODE = "2";
+    public static final String THIRD_NODE = "3";
     public static final String FIRST_EDGE = "1";
     public static final String SECOND_EDGE = "2";
     public static final String[] STRING_COLUMN_VALUES = new String[] {"France", "Germany"};
@@ -87,6 +88,30 @@ public class GraphGenerator {
         return this;
     }
 
+    public GraphGenerator generateTinyUndirectedGraph() {
+        Node n1 = graphModel.factory().newNode(FIRST_NODE);
+        Node n2 = graphModel.factory().newNode(SECOND_NODE);
+        Edge e = graphModel.factory().newEdge(FIRST_EDGE, n1, n2, 0, 1.0, false);
+        graphModel.getDirectedGraph().addNode(n1);
+        graphModel.getDirectedGraph().addNode(n2);
+        graphModel.getDirectedGraph().addEdge(e);
+        return this;
+    }
+
+    public GraphGenerator generateTinyMixedGraph() {
+        Node n1 = graphModel.factory().newNode(FIRST_NODE);
+        Node n2 = graphModel.factory().newNode(SECOND_NODE);
+        Node n3 = graphModel.factory().newNode(THIRD_NODE);
+        Edge e1 = graphModel.factory().newEdge(FIRST_EDGE, n1, n2, 0, 1.0, false);
+        Edge e2 = graphModel.factory().newEdge(SECOND_EDGE, n1, n3, 0, 1.0, true);
+        graphModel.getGraph().addNode(n1);
+        graphModel.getGraph().addNode(n2);
+        graphModel.getGraph().addNode(n3);
+        graphModel.getGraph().addEdge(e1);
+        graphModel.getGraph().addEdge(e2);
+        return this;
+    }
+
     public GraphGenerator addNodeLabels() {
         for (Node n : graphModel.getGraph().getNodes()) {
             n.setLabel(n.getId().toString());

modules/Utils/pom.xml

@@ -24,6 +24,10 @@
             <groupId>${project.groupId}</groupId>
             <artifactId>core-library-wrapper</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.netbeans.api</groupId>
+            <artifactId>org-openide-util</artifactId>
+        </dependency>
     </dependencies>
 
     <build>

modules/Utils/src/main/java/org/gephi/utils/VersionUtils.java

+package org.gephi.utils;
+
+import org.openide.util.NbBundle;
+
+public class VersionUtils {
+
+    /**
+     * Returns the current version of the Gephi application.
+     *
+     * @return gephi version
+     */
+    public static String getGephiVersion() {
+        return NbBundle.getBundle("org.netbeans.core.startup.Bundle").getString("currentVersion")
+            .replaceAll("( [0-9]{12})$", "");
+    }
+}