refactor: improve array aggregation examples and explanatory notes

Author: ricardohsmello

java/100_aggregation_pipeline_match.ipynb

@@ -67,7 +67,6 @@
     "import org.bson.conversions.Bson;\n",
     "\n",
     "// Configure SLF4J Simple Logger to suppress MongoDB driver logs in the notebook output.\n",
-    "\n",
     "System.setProperty(\"org.slf4j.simpleLogger.defaultLogLevel\", \"off\");\n",
     "System.setProperty(\"org.slf4j.simpleLogger.log.org.mongodb.driver\", \"off\");\n",
     "\n",

java/101_aggregation_pipeline_arrays.ipynb

@@ -56,6 +56,9 @@
     "import static com.mongodb.client.model.Filters.in;\n",
     "import static com.mongodb.client.model.Sorts.descending;\n",
     "\n",
+    "import static com.mongodb.client.model.Projections.include;\n",
+    "import static com.mongodb.client.model.Projections.excludeId;\n",
+    "import static com.mongodb.client.model.Projections.fields;\n",
     "\n",
     "import static com.mongodb.client.model.Aggregates.match;\n",
     "import static com.mongodb.client.model.Aggregates.project;\n",
@@ -66,7 +69,6 @@
     "import org.bson.conversions.Bson;\n",
     "\n",
     "// Configure SLF4J Simple Logger to suppress MongoDB driver logs in the notebook output.\n",
-    "\n",
     "System.setProperty(\"org.slf4j.simpleLogger.defaultLogLevel\", \"off\");\n",
     "System.setProperty(\"org.slf4j.simpleLogger.log.org.mongodb.driver\", \"off\");\n",
     "\n",
@@ -118,15 +120,18 @@
    },
    "outputs": [],
    "source": [
-    "AggregateIterable<Document> result = books.aggregate(Arrays.asList(\n",
-    "    Aggregates.match(Filters.all(\"genres\", \"Family Life\", \"Fiction\")),\n",
-    "    Aggregates.project(new Document()\n",
-    "        .append(\"title\", 1)\n",
-    "        .append(\"genres\", 1)\n",
+    "AggregateIterable<Document> result = books.aggregate(\n",
+    "    List.of(\n",
+    "        match(all(\"genres\", \"Family Life\", \"Fiction\")),\n",
+    "        project(\n",
+    "            fields(\n",
+    "                include(\"title\", \"genres\"),\n",
+    "                excludeId()\n",
+    "            )\n",
+    "        )\n",
     "    )\n",
-    "));\n",
+    ");\n",
     "\n",
-    "// Iterate through the results\n",
     "for (Document doc : result) {\n",
     "    System.out.println(\"book: \" + doc.toJson());\n",
     "}"
@@ -137,7 +142,7 @@
    "id": "9f6caab3",
    "metadata": {},
    "source": [
-    "### $match: $in\n",
+    "### $match with the `$in` operator\n",
     "\n",
     "Use `$in` to find books where the `genres` array contains at least one of the specified values."
    ]
@@ -153,15 +158,18 @@
    },
    "outputs": [],
    "source": [
-    "AggregateIterable<Document> result = books.aggregate(Arrays.asList(\n",
-    "    Aggregates.match(Filters.in(\"genres\", \"Family Life\", \"Fiction\")),\n",
-    "    Aggregates.project(new Document()\n",
-    "        .append(\"title\", 1)\n",
-    "        .append(\"genres\", 1)\n",
+    "// Note: `Document` can also be used here because it implements `Bson`.\n",
+    "\n",
+    "AggregateIterable<Document> result = books.aggregate(\n",
+    "    List.of(\n",
+    "        Aggregates.match(Filters.in(\"genres\", \"Family Life\", \"Fiction\")),\n",
+    "        Aggregates.project(new Document()\n",
+    "            .append(\"title\", 1)\n",
+    "            .append(\"genres\", 1)\n",
+    "        )\n",
     "    )\n",
-    "));\n",
+    ");\n",
     "\n",
-    "// Iterate through the results\n",
     "for (Document doc : result) {\n",
     "    System.out.println(\"book: \" + doc.toJson());\n",
     "}"