feat: support writing records as nested properties

Author: bevzzz

src/it/java/io/weaviate/integration/DataITest.java

@@ -468,6 +468,12 @@ public void testDataTypes() throws IOException {
 
   }
 
+  record Address(
+      String street,
+      @io.weaviate.client6.v1.api.collections.annotations.Property("building_nr") int buildingNr,
+      @io.weaviate.client6.v1.api.collections.annotations.Property("isOneWay") boolean oneWay) {
+  }
+
   @Test
   public void testNestedProperties_insertMany() throws IOException {
     // Arrange
@@ -486,10 +492,10 @@ public void testNestedProperties_insertMany() throws IOException {
         "street", "Burggasse",
         "building_nr", 51,
         "isOneWay", true));
-    Map<String, Object> house_2 = Map.of("address", Map.of(
-        "street", "Port Mariland St.",
-        "building_nr", 111,
-        "isOneWay", false));
+    Map<String, Object> house_2 = Map.of("address", new Address(
+        "Port Mariland St.",
+        111,
+        false));
 
     // Act
     var result = buildings.data.insertMany(house_1, house_2);

src/main/java/io/weaviate/client6/v1/api/collections/data/InsertManyRequest.java

@@ -293,6 +293,20 @@ private static com.google.protobuf.Value marshalValue(Object value) {
             protoNested.putFields((String) nested.getKey(), nestedValue);
           });
       protoValue.setStructValue(protoNested);
+    } else if (value instanceof Record r) {
+      @SuppressWarnings("unchecked")
+      CollectionDescriptor<? super Record> recordDescriptor = (CollectionDescriptor<? super Record>) CollectionDescriptor
+          .ofClass(r.getClass());
+      var protoRecord = com.google.protobuf.Struct.newBuilder();
+      recordDescriptor.propertiesReader(r).readProperties().entrySet().stream()
+          .forEach(recordField -> {
+            var nestedValue = marshalValue(recordField.getValue());
+            if (nestedValue == null) {
+              return;
+            }
+            protoRecord.putFields((String) recordField.getKey(), nestedValue);
+          });
+      protoValue.setStructValue(protoRecord);
     } else {
       throw new IllegalArgumentException("data type " + value.getClass() + " is not supported");
     }