Polishing.

Pattern matching usage.
Diamond operator usage.
Remove unused import.
isEmpty usage.

Original pull request #1912

spring-data-relational/src/main/java/org/springframework/data/relational/core/conversion/DbAction.java

@@ -209,7 +209,7 @@ public interface DbAction<T> {
 	 * Note that deletes for contained entities that reference the root are to be represented by separate
 	 * {@link DbAction}s.
 	 * </p>
-	 * 
+	 *
 	 * @param <T> type of the entity for which this represents a database interaction.
 	 */
 	final class DeleteRoot<T> implements DbAction<T> {
@@ -274,7 +274,7 @@ public interface DbAction<T> {
 	 * Note that deletes for contained entities that reference the root are to be represented by separate
 	 * {@link DbAction}s.
 	 * </p>
-	 * 
+	 *
 	 * @param <T> type of the entity for which this represents a database interaction.
 	 */
 	final class DeleteAllRoot<T> implements DbAction<T> {
@@ -467,7 +467,7 @@ public interface DbAction<T> {
 		 * <p>
 		 * Values come from parent entities but one might also add values manually.
 		 * </p>
-		 * 
+		 *
 		 * @return guaranteed to be not {@code null}.
 		 */
 		Map<PersistentPropertyPath<RelationalPersistentProperty>, Object> getQualifiers();
@@ -479,7 +479,7 @@ public interface DbAction<T> {
 		default Pair<PersistentPropertyPath<RelationalPersistentProperty>, Object> getQualifier() {
 
 			Map<PersistentPropertyPath<RelationalPersistentProperty>, Object> qualifiers = getQualifiers();
-			if (qualifiers.size() == 0)
+			if (qualifiers.isEmpty())
 				return null;
 
 			if (qualifiers.size() > 1) {

spring-data-relational/src/main/java/org/springframework/data/relational/core/dialect/MariaDbDialect.java

@@ -17,7 +17,6 @@ package org.springframework.data.relational.core.dialect;
 
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.Collections;
 
 import org.springframework.data.relational.core.sql.IdentifierProcessing;
 

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/EmbeddedContext.java

@@ -23,9 +23,6 @@ package org.springframework.data.relational.core.mapping;
  */
 record EmbeddedContext(RelationalPersistentProperty ownerProperty) {
 
-	EmbeddedContext {
-	}
-
 	public String getEmbeddedPrefix() {
 		return ownerProperty.getEmbeddedPrefix();
 	}

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/InsertOnlyProperty.java

@@ -17,7 +17,6 @@ package org.springframework.data.relational.core.mapping;
 
 import java.lang.annotation.Documented;
 import java.lang.annotation.ElementType;
-import java.lang.annotation.Inherited;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/event/BeforeConvertEvent.java

@@ -15,8 +15,6 @@
  */
 package org.springframework.data.relational.core.mapping.event;
 
-import org.springframework.data.relational.core.conversion.AggregateChange;
-
 import java.io.Serial;
 
 /**
@@ -37,7 +35,7 @@ import java.io.Serial;
  * <li>SQL statements get applied to the database.</li>
  * <li>{@link AfterSaveCallback} and {@link AfterSaveEvent} get published.</li>
  * </ol>
- * 
+ *
  * @since 1.1
  * @author Jens Schauder
  * @author Mark Paluch

spring-data-relational/src/main/java/org/springframework/data/relational/core/sql/render/SelectStatementVisitor.java

@@ -101,9 +101,7 @@ class SelectStatementVisitor extends DelegatingVisitor implements PartRenderer {
 	@Override
 	public Delegation doLeave(Visitable segment) {
 
-		if (segment instanceof Select) {
-
-			Select select = (Select) segment;
+		if (segment instanceof Select select) {
 
 			builder.append("SELECT ");
 

spring-data-relational/src/main/java/org/springframework/data/relational/repository/query/CriteriaFactory.java

@@ -23,7 +23,6 @@ import org.springframework.data.relational.core.query.Criteria;
 import org.springframework.data.relational.core.sql.Expression;
 import org.springframework.data.repository.query.parser.Part;
 import org.springframework.util.Assert;
-import org.springframework.util.CollectionUtils;
 import org.springframework.util.ObjectUtils;
 
 /**