address compile warning

related to #10083

Signed-off-by: Jiandong Ma <[email protected]>

Author: mjd507

spring-integration-kafka/src/main/java/org/springframework/integration/kafka/dsl/KafkaTemplateSpec.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2023 the original author or authors.
+ * Copyright 2018-2025 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,12 +16,13 @@
 
 package org.springframework.integration.kafka.dsl;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.integration.dsl.IntegrationComponentSpec;
 import org.springframework.kafka.core.KafkaTemplate;
 import org.springframework.kafka.core.ProducerFactory;
 import org.springframework.kafka.support.ProducerListener;
 import org.springframework.kafka.support.converter.RecordMessageConverter;
-import org.springframework.lang.Nullable;
 
 /**
  * An {@link IntegrationComponentSpec} implementation for the {@link KafkaTemplate}.

spring-integration-kafka/src/main/java/org/springframework/integration/kafka/support/RawRecordHeaderErrorMessageStrategy.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2019 the original author or authors.
+ * Copyright 2017-2025 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,12 +19,13 @@
 import java.util.HashMap;
 import java.util.Map;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.core.AttributeAccessor;
 import org.springframework.integration.IntegrationMessageHeaderAccessor;
 import org.springframework.integration.support.ErrorMessageStrategy;
 import org.springframework.integration.support.ErrorMessageUtils;
 import org.springframework.kafka.support.KafkaHeaders;
-import org.springframework.lang.Nullable;
 import org.springframework.messaging.Message;
 import org.springframework.messaging.support.ErrorMessage;
 

spring-integration-kafka/src/main/java/org/springframework/integration/kafka/support/package-info.java

@@ -1,4 +1,5 @@
 /**
  * Provides support classes.
  */
+@org.jspecify.annotations.NullMarked
 package org.springframework.integration.kafka.support;