feat (core): Graph Commons JSON Converter

java/dev/enola/thing/gen/BUILD

@@ -49,6 +49,7 @@ java_library(
         "@maven//:com_google_auto_service_auto_service_annotations",
         "@maven//:com_google_errorprone_error_prone_annotations",
         "@maven//:com_google_errorprone_error_prone_type_annotations",
+        "@maven//:com_google_code_gson_gson",
         "@maven//:com_google_guava_guava",
         "@maven//:org_jspecify_jspecify",
         "@maven//:org_slf4j_slf4j_api",

java/dev/enola/thing/gen/graphcommons/GraphCommonsJsonGenerator.java

@@ -0,0 +1,72 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Copyright 2024 The Enola <https://enola.dev> Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package dev.enola.thing.gen.graphcommons;
+
+import com.google.common.io.CharStreams;
+import com.google.gson.FormattingStyle;
+import com.google.gson.Strictness;
+import com.google.gson.stream.JsonWriter;
+
+import dev.enola.common.context.TLC;
+import dev.enola.common.convert.ConversionException;
+import dev.enola.thing.Thing;
+import dev.enola.thing.gen.ThingsIntoAppendableConverter;
+import dev.enola.thing.repo.StackedThingProvider;
+import dev.enola.thing.repo.ThingProvider;
+
+import java.io.IOException;
+
+/** Generator of JSON Format used by <a href="https://graphcommons.com/>Graph Commons</a>. */
+public class GraphCommonsJsonGenerator implements ThingsIntoAppendableConverter {
+
+    @Override
+    public boolean convertInto(Iterable<Thing> from, Appendable out)
+            throws ConversionException, IOException {
+        var writer = CharStreams.asWriter(out);
+        var jsonWriter = new JsonWriter(writer);
+        jsonWriter.setStrictness(Strictness.STRICT);
+        jsonWriter.setFormattingStyle(FormattingStyle.PRETTY); // TODO COMPACT, if ?pretty
+        jsonWriter.setSerializeNulls(false);
+        jsonWriter.setHtmlSafe(true); // TODO ?
+        try (var ctx = TLC.open()) {
+            ctx.push(ThingProvider.class, new StackedThingProvider(from));
+            out.append("{\n \"nodes\": [\n");
+            for (Thing thing : from) printThingNode(thing, jsonWriter);
+            out.append(" ],\n \"edges\": [\n");
+            for (Thing thing : from) printThingEdges(thing, jsonWriter);
+            out.append(" ],\n \"nodeTypes\": [\n");
+            // TODO printThingNodeTypes()
+            out.append(" ],\n \"edgeTypes\": [\n");
+            // TODO printThingEdgeTypes()
+            out.append(" ],\n");
+            out.append(" \"name\": \"Enola.dev\"\n");
+            out.append('}');
+        }
+        jsonWriter.flush();
+        writer.close();
+        return true;
+    }
+
+    private void printThingNode(Thing thing, JsonWriter out) throws IOException {
+        out.beginObject();
+        out.name("id").value(thing.iri());
+        out.endObject();
+    }
+
+    private void printThingEdges(Thing thing, JsonWriter out) {}
+}

java/dev/enola/thing/gen/graphcommons/GraphCommonsMediaType.java

@@ -0,0 +1,20 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Copyright 2024 The Enola <https://enola.dev> Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package dev.enola.thing.gen.graphcommons;
+
+public class GraphCommonsMediaType {}

java/dev/enola/thing/gen/graphcommons/GraphCommonsResourceConverter.java

@@ -0,0 +1,31 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Copyright 2024 The Enola <https://enola.dev> Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package dev.enola.thing.gen.graphcommons;
+
+import dev.enola.common.io.resource.ReadableResource;
+import dev.enola.common.io.resource.WritableResource;
+import dev.enola.common.io.resource.convert.CatchingResourceConverter;
+
+public class GraphCommonsResourceConverter implements CatchingResourceConverter {
+
+    @Override
+    public boolean convertIntoThrows(ReadableResource from, WritableResource into)
+            throws Exception {
+        return false;
+    }
+}

java/dev/enola/thing/gen/graphviz/GraphvizGenerator.java

@@ -87,21 +87,21 @@ public boolean convertInto(Iterable<Thing> from, Appendable out)
             ctx.push(ThingProvider.class, new StackedThingProvider(from));
             for (Thing thing : from) {
                 thingIRIs.add(thing.iri());
-                printFullThing(thing, out, thingIRIs, linkIRIs);
+                printThing(thing, out, thingIRIs, linkIRIs);
             }
             // Remove links to all things which were processed after we processed them
             linkIRIs.removeAll(thingIRIs);
             // linkIRIs now contains things which were linked to but that have no properties
             for (String orphanIRI : linkIRIs) {
                 var orphanThing = new OnlyIRIThing(orphanIRI);
-                printFullThing(orphanThing, out, thingIRIs, linkIRIs);
+                printThing(orphanThing, out, thingIRIs, linkIRIs);
             }
         }
         out.append("}\n");
         return true;
     }
 
-    private void printFullThing(
+    private void printThing(
             Thing thing, Appendable out, Set<String> thingIRIs, Set<String> linkIRIs)
             throws IOException {
         boolean full = TLC.optional(Flags.FULL).orElse(false);