refactor: improve unwind example readability and projection style

Author: ricardohsmello

java/101_aggregation_pipeline_arrays.ipynb

@@ -132,6 +132,7 @@
     "    )\n",
     ");\n",
     "\n",
+    "// Iterate through the results\n",
     "for (Document doc : result) {\n",
     "    System.out.println(\"book: \" + doc.toJson());\n",
     "}"
@@ -170,6 +171,7 @@
     "    )\n",
     ");\n",
     "\n",
+    "// Iterate through the results\n",
     "for (Document doc : result) {\n",
     "    System.out.println(\"book: \" + doc.toJson());\n",
     "}"

java/102_aggregation_pipeline_unwind.ipynb

@@ -49,8 +49,16 @@
     "import com.mongodb.client.model.Filters;\n",
     "import org.bson.Document;\n",
     "\n",
-    "// Configure SLF4J Simple Logger to suppress MongoDB driver logs in the notebook output.\n",
+    "import static com.mongodb.client.model.Filters.eq;\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",
+    "import static com.mongodb.client.model.Aggregates.unwind;\n",
     "\n",
+    "// Configure SLF4J Simple Logger to suppress MongoDB driver logs in the notebook output.\n",
     "System.setProperty(\"org.slf4j.simpleLogger.defaultLogLevel\", \"off\");\n",
     "System.setProperty(\"org.slf4j.simpleLogger.log.org.mongodb.driver\", \"off\");\n",
     "\n",
@@ -83,7 +91,7 @@
    "source": [
     "## $unwind\n",
     "\n",
-    "This pipeline first selects the book with `_id` `\"0004127382\"` and then uses `$unwind` to split the `attributes` array into separate documents. Each result contains the book title and one individual attribute.\n"
+    "This pipeline first selects the book with `_id` `\"0004127382\"`, then uses `$unwind` to split the `attributes` array into separate documents, and finally uses `$project` to return only the `title` and `attributes` fields."
    ]
   },
   {
@@ -97,14 +105,13 @@
    },
    "outputs": [],
    "source": [
-    "AggregateIterable<Document> result = books.aggregate(List.of(\n",
-    "    Aggregates.match(Filters.eq(\"_id\", \"0004127382\")),\n",
-    "    Aggregates.unwind(\"$attributes\"),    \n",
-    "    Aggregates.project(new Document()\n",
-    "        .append(\"title\", 1)\n",
-    "        .append(\"attributes\", 1)\n",
+    "AggregateIterable<Document> result = books.aggregate(\n",
+    "    List.of(\n",
+    "        match(eq(\"_id\", \"0004127382\")),\n",
+    "        unwind(\"$attributes\"),\n",
+    "        project(fields(include(\"title\", \"attributes\"), excludeId()))\n",
     "    )\n",
-    "));\n",
+    ");\n",
     "\n",
     "// Iterate through the results\n",
     "for (Document doc : result) {\n",