Add @Serial annotation to all serialVersionUID fields.

- Enhance code readability and maintainability
- Improve static analysis capabilities
- Ensure proper declaration of serialVersionUID fields

Closes #3584

spring-data-envers/src/test/java/org/springframework/data/envers/sample/QCountry.java

@@ -23,6 +23,8 @@ import com.querydsl.core.types.dsl.StringPath;
 
 import static com.querydsl.core.types.PathMetadataFactory.forVariable;
 
+import java.io.Serial;
+
 /**
  * Query class for Country domain.
  *
@@ -30,7 +32,7 @@ import static com.querydsl.core.types.PathMetadataFactory.forVariable;
  */
 public class QCountry extends EntityPathBase<Country> {
 
-	private static final long serialVersionUID = -936338527;
+	@Serial private static final long serialVersionUID = -936338527;
 
 	private static final PathInits INITS = PathInits.DIRECT2;
 

spring-data-jpa/src/main/java/org/springframework/data/jpa/domain/JpaSort.java

@@ -28,6 +28,7 @@ import org.springframework.data.domain.Sort;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
+import java.io.Serial;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -45,7 +46,7 @@ import java.util.List;
  */
 public class JpaSort extends Sort {
 
-	private static final long serialVersionUID = 1L;
+	@Serial private static final long serialVersionUID = 1L;
 
 	private JpaSort(Direction direction, List<Path<?, ?>> paths) {
 		this(Collections.<Order>emptyList(), direction, paths);
@@ -322,7 +323,7 @@ public class JpaSort extends Sort {
 	 */
 	public static class JpaOrder extends Order {
 
-		private static final long serialVersionUID = 1L;
+		@Serial private static final long serialVersionUID = 1L;
 
 		private final boolean unsafe;
 

spring-data-jpa/src/main/java/org/springframework/data/jpa/domain/Specification.java

@@ -21,6 +21,7 @@ import jakarta.persistence.criteria.CriteriaQuery;
 import jakarta.persistence.criteria.Predicate;
 import jakarta.persistence.criteria.Root;
 
+import java.io.Serial;
 import java.io.Serializable;
 import java.util.Arrays;
 import java.util.stream.StreamSupport;
@@ -41,7 +42,7 @@ import org.springframework.lang.Nullable;
  */
 public interface Specification<T> extends Serializable {
 
-	long serialVersionUID = 1L;
+	@Serial long serialVersionUID = 1L;
 
 	/**
 	 * Negates the given {@link Specification}.

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/InvalidJpaQueryMethodException.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.jpa.repository.query;
 
+import java.io.Serial;
+
 /**
  * Signals that we encountered an invalid query method.
  *
@@ -23,7 +25,7 @@ package org.springframework.data.jpa.repository.query;
  */
 public class InvalidJpaQueryMethodException extends RuntimeException {
 
-	private static final long serialVersionUID = 1L;
+	@Serial private static final long serialVersionUID = 1L;
 
 	/**
 	 * Creates a new {@link InvalidJpaQueryMethodException} with the given message.

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/support/SimpleJpaRepository.java

@@ -31,6 +31,7 @@ import jakarta.persistence.criteria.Path;
 import jakarta.persistence.criteria.Predicate;
 import jakarta.persistence.criteria.Root;
 
+import java.io.Serial;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
@@ -932,7 +933,7 @@ public class SimpleJpaRepository<T, ID> implements JpaRepositoryImplementation<T
 	@SuppressWarnings("rawtypes")
 	private static final class ByIdsSpecification<T> implements Specification<T> {
 
-		private static final long serialVersionUID = 1L;
+		@Serial private static final long serialVersionUID = 1L;
 
 		private final JpaEntityInformation<T, ?> entityInformation;
 
@@ -961,7 +962,7 @@ public class SimpleJpaRepository<T, ID> implements JpaRepositoryImplementation<T
 	 */
 	private static class ExampleSpecification<T> implements Specification<T> {
 
-		private static final long serialVersionUID = 1L;
+		@Serial private static final long serialVersionUID = 1L;
 
 		private final Example<T> example;
 		private final EscapeCharacter escapeCharacter;

spring-data-jpa/src/test/java/org/springframework/data/jpa/domain/sample/Account.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.jpa.domain.sample;
 
+import java.io.Serial;
+
 import jakarta.persistence.Entity;
 
 import org.springframework.data.jpa.domain.AbstractPersistable;

spring-data-jpa/src/test/java/org/springframework/data/jpa/domain/sample/EmbeddedIdExampleEmployeePK.java

@@ -15,6 +15,7 @@
  */
 package org.springframework.data.jpa.domain.sample;
 
+import java.io.Serial;
 import java.io.Serializable;
 
 import jakarta.persistence.Column;
@@ -25,7 +26,7 @@ import jakarta.persistence.Embeddable;
  */
 @Embeddable
 public class EmbeddedIdExampleEmployeePK implements Serializable {
-	private static final long serialVersionUID = 1L;
+	@Serial private static final long serialVersionUID = 1L;
 
 	@Column(nullable = false) private Long employeeId;
 

spring-data-jpa/src/test/java/org/springframework/data/jpa/domain/sample/IdClassExampleEmployeePK.java

@@ -15,13 +15,14 @@
  */
 package org.springframework.data.jpa.domain.sample;
 
+import java.io.Serial;
 import java.io.Serializable;
 
 /**
  * @author Thomas Darimont
  */
 public class IdClassExampleEmployeePK implements Serializable {
-	private static final long serialVersionUID = 1L;
+	@Serial private static final long serialVersionUID = 1L;
 
 	private long empId;
 	private long department;

spring-data-jpa/src/test/java/org/springframework/data/jpa/domain/sample/ItemId.java

@@ -15,6 +15,7 @@
  */
 package org.springframework.data.jpa.domain.sample;
 
+import java.io.Serial;
 import java.io.Serializable;
 
 /**
@@ -25,7 +26,7 @@ import java.io.Serializable;
  */
 public class ItemId implements Serializable {
 
-	private static final long serialVersionUID = -2986871112875450036L;
+	@Serial private static final long serialVersionUID = -2986871112875450036L;
 
 	private Integer id;
 	private Integer manufacturerId;

spring-data-jpa/src/test/java/org/springframework/data/jpa/domain/sample/ItemSiteId.java

@@ -15,6 +15,7 @@
  */
 package org.springframework.data.jpa.domain.sample;
 
+import java.io.Serial;
 import java.io.Serializable;
 
 /**
@@ -25,7 +26,7 @@ import java.io.Serializable;
  */
 public class ItemSiteId implements Serializable {
 
-	private static final long serialVersionUID = 1822540289216799357L;
+	@Serial private static final long serialVersionUID = 1822540289216799357L;
 
 	private ItemId item;
 	private Integer site;

spring-data-jpa/src/test/java/org/springframework/data/jpa/domain/sample/PersistableWithIdClassPK.java

@@ -17,6 +17,7 @@ package org.springframework.data.jpa.domain.sample;
 
 import static org.springframework.util.ObjectUtils.*;
 
+import java.io.Serial;
 import java.io.Serializable;
 
 /**
@@ -25,7 +26,7 @@ import java.io.Serializable;
  */
 public class PersistableWithIdClassPK implements Serializable {
 
-	private static final long serialVersionUID = 23126782341L;
+	@Serial private static final long serialVersionUID = 23126782341L;
 
 	private Long first;
 	private Long second;

spring-data-jpa/src/test/java/org/springframework/data/jpa/domain/sample/PersistableWithSingleIdClassPK.java

@@ -17,6 +17,7 @@ package org.springframework.data.jpa.domain.sample;
 
 import static org.springframework.util.ObjectUtils.*;
 
+import java.io.Serial;
 import java.io.Serializable;
 
 /**
@@ -24,7 +25,7 @@ import java.io.Serializable;
  */
 public class PersistableWithSingleIdClassPK implements Serializable {
 
-	private static final long serialVersionUID = 23126782341L;
+	@Serial private static final long serialVersionUID = 23126782341L;
 
 	private Long first;
 

spring-data-jpa/src/test/java/org/springframework/data/jpa/domain/sample/SampleEntityPK.java

@@ -15,6 +15,7 @@
  */
 package org.springframework.data.jpa.domain.sample;
 
+import java.io.Serial;
 import java.io.Serializable;
 
 import jakarta.persistence.Column;
@@ -25,7 +26,7 @@ import org.springframework.util.Assert;
 @Embeddable
 public class SampleEntityPK implements Serializable {
 
-	private static final long serialVersionUID = 231060947L;
+	@Serial private static final long serialVersionUID = 231060947L;
 
 	@Column(nullable = false)
 	private String first;

spring-data-jpa/src/test/java/org/springframework/data/jpa/domain/sample/Site.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.jpa.domain.sample;
 
+import java.io.Serial;
+
 import jakarta.persistence.Entity;
 import jakarta.persistence.GeneratedValue;
 import jakarta.persistence.Id;
@@ -31,7 +33,7 @@ import jakarta.persistence.Table;
 @Table
 public class Site implements java.io.Serializable {
 
-	private static final long serialVersionUID = 1L;
+	@Serial private static final long serialVersionUID = 1L;
 
 	@Id @GeneratedValue Integer id;