Address NullPointerException in CosmosDataItemSource ctor (Azure#35201)

* Address NullPointerException in CosmosDataItemSource ctor

Address NullPointerException when Spark runtime hasn't been initialized when CosmosDataItemSource ctor is called

* Update changelog

* Update CosmosItemsDataSource.scala

Author: FabianMeiswinkel

sdk/cosmos/azure-cosmos-spark_3-1_2-12/CHANGELOG.md

@@ -14,7 +14,8 @@
 
 #### Bugs Fixed
 * Fixed `IllegalArgumentException` when different throughput control group is defined on the same container - See [PR 34702](https://github.com/Azure/azure-sdk-for-java/pull/34702)
-
+* Addressed `NullPointerException` in `CosmosDataItemSource` constructor when Spark runtime initialization hasn't completed yet. - See [PR 35201](https://github.com/Azure/azure-sdk-for-java/pull/35201)
+ 
 ### 4.18.1 (2023-04-10)
 
 #### Bugs Fixed

sdk/cosmos/azure-cosmos-spark_3-2_2-12/CHANGELOG.md

@@ -14,6 +14,7 @@
 
 #### Bugs Fixed
 * Fixed `IllegalArgumentException` when different throughput control group is defined on the same container - See [PR 34702](https://github.com/Azure/azure-sdk-for-java/pull/34702)
+* Addressed `NullPointerException` in `CosmosDataItemSource` constructor when Spark runtime initialization hasn't completed yet. - See [PR 35201](https://github.com/Azure/azure-sdk-for-java/pull/35201)
 
 ### 4.18.1 (2023-04-10)
 

sdk/cosmos/azure-cosmos-spark_3-3_2-12/CHANGELOG.md

@@ -14,6 +14,7 @@
 
 #### Bugs Fixed
 * Fixed `IllegalArgumentException` when different throughput control group is defined on the same container - See [PR 34702](https://github.com/Azure/azure-sdk-for-java/pull/34702)
+* Addressed `NullPointerException` in `CosmosDataItemSource` constructor when Spark runtime initialization hasn't completed yet. - See [PR 35201](https://github.com/Azure/azure-sdk-for-java/pull/35201)
 
 ### 4.18.1 (2023-04-10)
 

sdk/cosmos/azure-cosmos-spark_3_2-12/src/main/scala/com/azure/cosmos/spark/CosmosItemsDataSource.scala

@@ -23,8 +23,10 @@ import scala.collection.JavaConverters._
 class CosmosItemsDataSource extends DataSourceRegister with TableProvider with BasicLoggingTrait {
   logInfo(s"Instantiated ${this.getClass.getSimpleName}")
 
-  assertOnSparkDriver()
-  private lazy val sparkSession = SparkSession.active
+  private lazy val sparkSession = {
+    assertOnSparkDriver()
+    SparkSession.active
+  }
 
   /**
    * Infer the schema of the table identified by the given options.