fix: make JsonObjectReader close operations null-safe

Signed-off-by: banseok1216 <bansuk1216@naver.com>

Author: banseok1216

spring-batch-infrastructure/src/main/java/org/springframework/batch/infrastructure/item/json/GsonJsonObjectReader.java

@@ -97,11 +97,14 @@ public void open(Resource resource) throws Exception {
 		return null;
 	}
 
-	@SuppressWarnings("DataFlowIssue")
 	@Override
 	public void close() throws Exception {
-		this.inputStream.close();
-		this.jsonReader.close();
+		if (inputStream != null) {
+			inputStream.close();
+		}
+		if (jsonReader != null) {
+			jsonReader.close();
+		}
 	}
 
 	@SuppressWarnings("DataFlowIssue")

spring-batch-infrastructure/src/main/java/org/springframework/batch/infrastructure/item/json/JacksonJsonObjectReader.java

@@ -106,11 +106,14 @@ public void open(Resource resource) throws Exception {
 		return null;
 	}
 
-	@SuppressWarnings("DataFlowIssue")
 	@Override
 	public void close() throws Exception {
-		this.inputStream.close();
-		this.jsonParser.close();
+		if (inputStream != null) {
+			inputStream.close();
+		}
+		if (jsonParser != null) {
+			jsonParser.close();
+		}
 	}
 
 	@SuppressWarnings("DataFlowIssue")