address a comment

Author: HyukjinKwon

python/pyspark/sql/streaming/listener.py

@@ -26,6 +26,7 @@
 
 if TYPE_CHECKING:
     from py4j.java_gateway import JavaObject
+    from pyspark.sql import SparkSession
 
 
 class StreamingQueryListener(ABC):
@@ -64,19 +65,17 @@ class StreamingQueryListener(ABC):
     """
 
     def _set_spark_session(
-        self, spark: "SparkSession"  # type: ignore[name-defined] # noqa: F821
+        self, session: "SparkSession"  # type: ignore[name-defined] # noqa: F821
     ) -> None:
-        self._sparkSession = spark
+        if self.spark is not None:
+            self.spark = session
 
     @property
     def spark(self) -> Optional["SparkSession"]:  # type: ignore[name-defined] # noqa: F821
-        if hasattr(self, "_sparkSession"):
-            return self._sparkSession
-        else:
-            return None
+        return getattr(self, "_sparkSession", None)
 
     @spark.setter
-    def spark(self, session):
+    def spark(self, session: "SparkSession") -> None:
         # For backward compatibility
         self._sparkSession = session