diff --git a/spring-batch-core/src/main/java/org/springframework/batch/core/repository/dao/JdbcJobInstanceDao.java b/spring-batch-core/src/main/java/org/springframework/batch/core/repository/dao/JdbcJobInstanceDao.java
index 30b087867..61d7d0d32 100644
--- a/spring-batch-core/src/main/java/org/springframework/batch/core/repository/dao/JdbcJobInstanceDao.java
+++ b/spring-batch-core/src/main/java/org/springframework/batch/core/repository/dao/JdbcJobInstanceDao.java
@@ -353,7 +353,7 @@ public class JdbcJobInstanceDao extends AbstractJdbcBatchMetadataDao implements
 	 * @author Dave Syer
 	 *
 	 */
-	private final class JobInstanceRowMapper implements RowMapper<JobInstance> {
+	private static final class JobInstanceRowMapper implements RowMapper<JobInstance> {
 
 		public JobInstanceRowMapper() {
 		}
diff --git a/spring-batch-core/src/main/java/org/springframework/batch/core/step/builder/FaultTolerantStepBuilder.java b/spring-batch-core/src/main/java/org/springframework/batch/core/step/builder/FaultTolerantStepBuilder.java
index 186c96834..1efb06b8b 100644
--- a/spring-batch-core/src/main/java/org/springframework/batch/core/step/builder/FaultTolerantStepBuilder.java
+++ b/spring-batch-core/src/main/java/org/springframework/batch/core/step/builder/FaultTolerantStepBuilder.java
@@ -694,7 +694,7 @@ public class FaultTolerantStepBuilder<I, O> extends SimpleStepBuilder<I, O> {
 	 * must be handled in the implementation or the step will terminate
 	 *
 	 */
-	private class TerminateOnExceptionChunkListenerDelegate implements ChunkListener {
+	private static class TerminateOnExceptionChunkListenerDelegate implements ChunkListener {
 
 		private ChunkListener chunkListener;
 
diff --git a/spring-batch-core/src/main/java/org/springframework/batch/core/step/item/BatchRetryTemplate.java b/spring-batch-core/src/main/java/org/springframework/batch/core/step/item/BatchRetryTemplate.java
index 01f78cd1b..10a73504c 100644
--- a/spring-batch-core/src/main/java/org/springframework/batch/core/step/item/BatchRetryTemplate.java
+++ b/spring-batch-core/src/main/java/org/springframework/batch/core/step/item/BatchRetryTemplate.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2013 the original author or authors.
+ * Copyright 2006-2023 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.
@@ -52,11 +52,12 @@ import java.util.List;
  * other items in the same batch fail fatally first.
  *
  * @author Dave Syer
+ * @author Mahmoud Ben Hassine
  *
  */
 public class BatchRetryTemplate implements RetryOperations {
 
-	private class BatchRetryState extends DefaultRetryState {
+	private static class BatchRetryState extends DefaultRetryState {
 
 		private final Collection<RetryState> keys;
 
diff --git a/spring-batch-core/src/test/java/org/springframework/batch/core/listener/JobListenerFactoryBeanTests.java b/spring-batch-core/src/test/java/org/springframework/batch/core/listener/JobListenerFactoryBeanTests.java
index ad365e1b9..59bdb90e4 100644
--- a/spring-batch-core/src/test/java/org/springframework/batch/core/listener/JobListenerFactoryBeanTests.java
+++ b/spring-batch-core/src/test/java/org/springframework/batch/core/listener/JobListenerFactoryBeanTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2023 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.
@@ -37,6 +37,7 @@ import org.springframework.core.Ordered;
 
 /**
  * @author Lucas Ward
+ * @author Mahmoud Ben Hassine
  *
  */
 class JobListenerFactoryBeanTests {
@@ -233,7 +234,7 @@ class JobListenerFactoryBeanTests {
 		assertThrows(IllegalArgumentException.class, factoryBean::getObject);
 	}
 
-	private class JobListenerWithInterface implements JobExecutionListener {
+	private static class JobListenerWithInterface implements JobExecutionListener {
 
 		boolean beforeJobCalled = false;
 
@@ -251,7 +252,7 @@ class JobListenerFactoryBeanTests {
 
 	}
 
-	private class AnnotatedTestClass {
+	private static class AnnotatedTestClass {
 
 		boolean beforeJobCalled = false;
 
diff --git a/spring-batch-core/src/test/java/org/springframework/batch/core/listener/MulticasterBatchListenerTests.java b/spring-batch-core/src/test/java/org/springframework/batch/core/listener/MulticasterBatchListenerTests.java
index 9b4d28a3e..8d944be45 100644
--- a/spring-batch-core/src/test/java/org/springframework/batch/core/listener/MulticasterBatchListenerTests.java
+++ b/spring-batch-core/src/test/java/org/springframework/batch/core/listener/MulticasterBatchListenerTests.java
@@ -548,7 +548,7 @@ class MulticasterBatchListenerTests {
 		assertEquals("listener error", message, "Wrong message: " + message);
 	}
 
-	private final class AnnotationBasedStepListener {
+	private static final class AnnotationBasedStepListener {
 
 		private IllegalStateException exception = new IllegalStateException("listener error");
 
diff --git a/spring-batch-core/src/test/java/org/springframework/batch/core/listener/StepListenerFactoryBeanTests.java b/spring-batch-core/src/test/java/org/springframework/batch/core/listener/StepListenerFactoryBeanTests.java
index e7fd7153e..f01c8b2fa 100644
--- a/spring-batch-core/src/test/java/org/springframework/batch/core/listener/StepListenerFactoryBeanTests.java
+++ b/spring-batch-core/src/test/java/org/springframework/batch/core/listener/StepListenerFactoryBeanTests.java
@@ -363,7 +363,7 @@ class StepListenerFactoryBeanTests {
 		assertThrows(IllegalArgumentException.class, factoryBean::getObject);
 	}
 
-	private class MultipleAfterStep implements StepExecutionListener {
+	private static class MultipleAfterStep implements StepExecutionListener {
 
 		int callcount = 0;
 
@@ -384,7 +384,7 @@ class StepListenerFactoryBeanTests {
 	}
 
 	@SuppressWarnings("unused")
-	private class ThreeStepExecutionListener implements StepExecutionListener {
+	private static class ThreeStepExecutionListener implements StepExecutionListener {
 
 		int callcount = 0;
 
@@ -413,7 +413,7 @@ class StepListenerFactoryBeanTests {
 	}
 
 	@SuppressWarnings("unused")
-	private class TestListener implements SkipListener<String, Integer> {
+	private static class TestListener implements SkipListener<String, Integer> {
 
 		boolean beforeStepCalled = false;
 
diff --git a/spring-batch-core/src/test/java/org/springframework/batch/core/step/item/FaultTolerantStepFactoryBeanRollbackTests.java b/spring-batch-core/src/test/java/org/springframework/batch/core/step/item/FaultTolerantStepFactoryBeanRollbackTests.java
index 4d2f762f7..ea08e1353 100644
--- a/spring-batch-core/src/test/java/org/springframework/batch/core/step/item/FaultTolerantStepFactoryBeanRollbackTests.java
+++ b/spring-batch-core/src/test/java/org/springframework/batch/core/step/item/FaultTolerantStepFactoryBeanRollbackTests.java
@@ -589,7 +589,7 @@ class FaultTolerantStepFactoryBeanRollbackTests {
 		return map;
 	}
 
-	class ExceptionThrowingChunkListener implements ChunkListener {
+	static class ExceptionThrowingChunkListener implements ChunkListener {
 
 		private int phase = -1;
 
diff --git a/spring-batch-core/src/test/java/org/springframework/batch/core/step/tasklet/TaskletStepTests.java b/spring-batch-core/src/test/java/org/springframework/batch/core/step/tasklet/TaskletStepTests.java
index dcb0a213c..ec1fcfb04 100644
--- a/spring-batch-core/src/test/java/org/springframework/batch/core/step/tasklet/TaskletStepTests.java
+++ b/spring-batch-core/src/test/java/org/springframework/batch/core/step/tasklet/TaskletStepTests.java
@@ -929,7 +929,7 @@ class TaskletStepTests {
 
 	}
 
-	private class MockRestartableItemReader extends AbstractItemStreamItemReader<String>
+	private static class MockRestartableItemReader extends AbstractItemStreamItemReader<String>
 			implements StepExecutionListener {
 
 		private boolean getExecutionAttributesCalled = false;
diff --git a/spring-batch-core/src/test/java/org/springframework/batch/core/test/ldif/builder/MappingLdifReaderBuilderTests.java b/spring-batch-core/src/test/java/org/springframework/batch/core/test/ldif/builder/MappingLdifReaderBuilderTests.java
index 7dadc3c00..d8942794b 100644
--- a/spring-batch-core/src/test/java/org/springframework/batch/core/test/ldif/builder/MappingLdifReaderBuilderTests.java
+++ b/spring-batch-core/src/test/java/org/springframework/batch/core/test/ldif/builder/MappingLdifReaderBuilderTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2022 the original author or authors.
+ * Copyright 2017-2023 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.
@@ -199,7 +199,7 @@ class MappingLdifReaderBuilderTests {
 
 	}
 
-	public class TestMapper implements RecordMapper<LdapAttributes> {
+	public static class TestMapper implements RecordMapper<LdapAttributes> {
 
 		@Nullable
 		@Override
diff --git a/spring-batch-core/src/test/java/org/springframework/batch/core/test/step/FaultTolerantStepIntegrationTests.java b/spring-batch-core/src/test/java/org/springframework/batch/core/test/step/FaultTolerantStepIntegrationTests.java
index 3cbb678d3..32579d820 100644
--- a/spring-batch-core/src/test/java/org/springframework/batch/core/test/step/FaultTolerantStepIntegrationTests.java
+++ b/spring-batch-core/src/test/java/org/springframework/batch/core/test/step/FaultTolerantStepIntegrationTests.java
@@ -260,7 +260,7 @@ class FaultTolerantStepIntegrationTests {
 		return stepExecution;
 	}
 
-	private class SkipIllegalArgumentExceptionSkipPolicy implements SkipPolicy {
+	private static class SkipIllegalArgumentExceptionSkipPolicy implements SkipPolicy {
 
 		@Override
 		public boolean shouldSkip(Throwable throwable, long skipCount) throws SkipLimitExceededException {
diff --git a/spring-batch-infrastructure/src/main/java/org/springframework/batch/item/file/SimpleBinaryBufferedReaderFactory.java b/spring-batch-infrastructure/src/main/java/org/springframework/batch/item/file/SimpleBinaryBufferedReaderFactory.java
index 4ccbd2b2d..0314896ff 100644
--- a/spring-batch-infrastructure/src/main/java/org/springframework/batch/item/file/SimpleBinaryBufferedReaderFactory.java
+++ b/spring-batch-infrastructure/src/main/java/org/springframework/batch/item/file/SimpleBinaryBufferedReaderFactory.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2007 the original author or authors.
+ * Copyright 2006-2023 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.
@@ -31,6 +31,7 @@ import org.springframework.core.io.Resource;
  * implementation.
  *
  * @author Dave Syer
+ * @author Mahmoud Ben Hassine
  * @since 2.1
  */
 public class SimpleBinaryBufferedReaderFactory implements BufferedReaderFactory {
@@ -61,7 +62,7 @@ public class SimpleBinaryBufferedReaderFactory implements BufferedReaderFactory
 	 * @author Dave Syer
 	 *
 	 */
-	private final class BinaryBufferedReader extends BufferedReader {
+	private static final class BinaryBufferedReader extends BufferedReader {
 
 		private final String ending;
 
diff --git a/spring-batch-infrastructure/src/test/java/org/springframework/batch/item/database/JdbcBatchItemWriterNamedParameterTests.java b/spring-batch-infrastructure/src/test/java/org/springframework/batch/item/database/JdbcBatchItemWriterNamedParameterTests.java
index 8bbcdcb8f..5a6cbb55d 100644
--- a/spring-batch-infrastructure/src/test/java/org/springframework/batch/item/database/JdbcBatchItemWriterNamedParameterTests.java
+++ b/spring-batch-infrastructure/src/test/java/org/springframework/batch/item/database/JdbcBatchItemWriterNamedParameterTests.java
@@ -54,7 +54,7 @@ public class JdbcBatchItemWriterNamedParameterTests {
 	private final String sql = "update foo set bar = :bar where id = :id";
 
 	@SuppressWarnings("unused")
-	private class Foo {
+	private static class Foo {
 
 		private Long id;
 
diff --git a/spring-batch-infrastructure/src/test/java/org/springframework/batch/support/SimpleMethodInvokerTests.java b/spring-batch-infrastructure/src/test/java/org/springframework/batch/support/SimpleMethodInvokerTests.java
index 9270d650f..2060de79a 100644
--- a/spring-batch-infrastructure/src/test/java/org/springframework/batch/support/SimpleMethodInvokerTests.java
+++ b/spring-batch-infrastructure/src/test/java/org/springframework/batch/support/SimpleMethodInvokerTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2023 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.
@@ -29,6 +29,7 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
 
 /**
  * @author Lucas Ward
+ * @author Mahmoud Ben Hassine
  *
  */
 class SimpleMethodInvokerTests {
@@ -106,7 +107,7 @@ class SimpleMethodInvokerTests {
 	}
 
 	@SuppressWarnings("unused")
-	private class TestClass {
+	private static class TestClass {
 
 		boolean beforeCalled = false;
 
diff --git a/spring-batch-integration/src/test/java/org/springframework/batch/integration/async/AsyncItemWriterTests.java b/spring-batch-integration/src/test/java/org/springframework/batch/integration/async/AsyncItemWriterTests.java
index 4d8a75f19..44a99d970 100644
--- a/spring-batch-integration/src/test/java/org/springframework/batch/integration/async/AsyncItemWriterTests.java
+++ b/spring-batch-integration/src/test/java/org/springframework/batch/integration/async/AsyncItemWriterTests.java
@@ -193,7 +193,7 @@ class AsyncItemWriterTests {
 		assertFalse(itemWriter.isClosed);
 	}
 
-	private class ListItemWriter implements ItemWriter<String> {
+	private static class ListItemWriter implements ItemWriter<String> {
 
 		protected List<String> items;
 
@@ -214,7 +214,7 @@ class AsyncItemWriterTests {
 
 	}
 
-	private class ListItemStreamWriter implements ItemStreamWriter<String> {
+	private static class ListItemStreamWriter implements ItemStreamWriter<String> {
 
 		public boolean isOpened = false;
 
diff --git a/spring-batch-test/src/main/java/org/springframework/batch/test/JobScopeTestExecutionListener.java b/spring-batch-test/src/main/java/org/springframework/batch/test/JobScopeTestExecutionListener.java
index 00c08f895..0096d88cf 100644
--- a/spring-batch-test/src/main/java/org/springframework/batch/test/JobScopeTestExecutionListener.java
+++ b/spring-batch-test/src/main/java/org/springframework/batch/test/JobScopeTestExecutionListener.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2021 the original author or authors.
+ * Copyright 2006-2023 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.
@@ -61,6 +61,7 @@ import org.springframework.util.ReflectionUtils.MethodCallback;
  *
  * @author Dave Syer
  * @author Jimmy Praet
+ * @author Mahmoud Ben Hassine
  */
 public class JobScopeTestExecutionListener implements TestExecutionListener {
 
@@ -139,7 +140,7 @@ public class JobScopeTestExecutionListener implements TestExecutionListener {
 	 * Look for a method returning the type provided, preferring one with the name
 	 * provided.
 	 */
-	private final class ExtractorMethodCallback implements MethodCallback {
+	private static final class ExtractorMethodCallback implements MethodCallback {
 
 		private String preferredName;
 
diff --git a/spring-batch-test/src/main/java/org/springframework/batch/test/StepScopeTestExecutionListener.java b/spring-batch-test/src/main/java/org/springframework/batch/test/StepScopeTestExecutionListener.java
index 3aa675fbf..8948ee440 100644
--- a/spring-batch-test/src/main/java/org/springframework/batch/test/StepScopeTestExecutionListener.java
+++ b/spring-batch-test/src/main/java/org/springframework/batch/test/StepScopeTestExecutionListener.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2021 the original author or authors.
+ * Copyright 2006-2023 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.
@@ -62,6 +62,7 @@ import org.springframework.util.ReflectionUtils.MethodCallback;
  *
  * @author Dave Syer
  * @author Chris Schaefer
+ * @author Mahmoud Ben Hassine
  */
 public class StepScopeTestExecutionListener implements TestExecutionListener {
 
@@ -142,7 +143,7 @@ public class StepScopeTestExecutionListener implements TestExecutionListener {
 	 * Look for a method returning the type provided, preferring one with the name
 	 * provided.
 	 */
-	private final class ExtractorMethodCallback implements MethodCallback {
+	private static final class ExtractorMethodCallback implements MethodCallback {
 
 		private String preferredName;