Add native support for @Convert on JPA entities

This commit infers the reflection hints required for converters
when they are specified with the @Convert annotation at class or
field level.

It also refines the hints generated for @Converter in order
to just generate the construct hint, not the public method one
which should be not needed.

Closes gh-29771

spring-orm/src/main/java/org/springframework/orm/jpa/persistenceunit/PersistenceManagedTypesBeanRegistrationAotProcessor.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.
@@ -23,6 +23,7 @@ import java.util.List;
 
 import javax.lang.model.element.Modifier;
 
+import jakarta.persistence.Convert;
 import jakarta.persistence.Converter;
 import jakarta.persistence.EntityListeners;
 import jakarta.persistence.IdClass;
@@ -156,9 +157,20 @@ class PersistenceManagedTypesBeanRegistrationAotProcessor implements BeanRegistr
 
 		private void contributeConverterHints(RuntimeHints hints, Class<?> managedClass) {
 			Converter converter = AnnotationUtils.findAnnotation(managedClass, Converter.class);
+			ReflectionHints reflectionHints = hints.reflection();
 			if (converter != null) {
-				hints.reflection().registerType(managedClass, MemberCategory.INVOKE_DECLARED_CONSTRUCTORS, MemberCategory.INVOKE_PUBLIC_METHODS);
+				reflectionHints.registerType(managedClass, MemberCategory.INVOKE_DECLARED_CONSTRUCTORS);
 			}
+			Convert convertClassAnnotation = AnnotationUtils.findAnnotation(managedClass, Convert.class);
+			if (convertClassAnnotation != null) {
+				reflectionHints.registerType(convertClassAnnotation.converter(), MemberCategory.INVOKE_DECLARED_CONSTRUCTORS);
+			}
+			ReflectionUtils.doWithFields(managedClass, field -> {
+				Convert convertFieldAnnotation = AnnotationUtils.findAnnotation(field, Convert.class);
+				if (convertFieldAnnotation != null && convertFieldAnnotation.converter() != void.class) {
+					reflectionHints.registerType(convertFieldAnnotation.converter(), MemberCategory.INVOKE_DECLARED_CONSTRUCTORS);
+				}
+			});
 		}
 
 		private void contributeCallbackHints(RuntimeHints hints, Class<?> managedClass) {

spring-orm/src/test/java/org/springframework/orm/jpa/domain/Employee.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.
@@ -17,6 +17,7 @@
 package org.springframework.orm.jpa.domain;
 
 import jakarta.persistence.Column;
+import jakarta.persistence.Convert;
 import jakarta.persistence.Entity;
 import jakarta.persistence.Id;
 import jakarta.persistence.IdClass;
@@ -24,6 +25,7 @@ import jakarta.persistence.PreRemove;
 
 @Entity
 @IdClass(EmployeeId.class)
+@Convert(converter = EmployeeKindConverter.class, attributeName = "kind")
 public class Employee {
 
 	@Id
@@ -36,6 +38,10 @@ public class Employee {
 
 	private EmployeeLocation location;
 
+	@Convert(converter = EmployeeCategoryConverter.class)
+	private EmployeeCategory category;
+
+	private EmployeeKind kind;
 
 	public String getName() {
 		return name;
@@ -61,6 +67,22 @@ public class Employee {
 		this.location = location;
 	}
 
+	public EmployeeCategory getCategory() {
+		return category;
+	}
+
+	public void setCategory(EmployeeCategory category) {
+		this.category = category;
+	}
+
+	public EmployeeKind getKind() {
+		return kind;
+	}
+
+	public void setKind(EmployeeKind kind) {
+		this.kind = kind;
+	}
+
 	@PreRemove
 	public void preRemove() {
 	}

spring-orm/src/test/java/org/springframework/orm/jpa/domain/EmployeeCategory.java

@@ -0,0 +1,29 @@
+/*
+ * 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.orm.jpa.domain;
+
+public class EmployeeCategory {
+	private String name;
+
+	public String getName() {
+		return name;
+	}
+
+	public void setName(String name) {
+		this.name = name;
+	}
+}

spring-orm/src/test/java/org/springframework/orm/jpa/domain/EmployeeCategoryConverter.java

@@ -0,0 +1,40 @@
+/*
+ * 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.orm.jpa.domain;
+
+import jakarta.persistence.AttributeConverter;
+
+public class EmployeeCategoryConverter implements AttributeConverter<EmployeeCategory, String> {
+
+	@Override
+	public String convertToDatabaseColumn(EmployeeCategory employeeCategory) {
+		if (employeeCategory != null) {
+			return employeeCategory.getName();
+		}
+		return null;
+	}
+
+	@Override
+	public EmployeeCategory convertToEntityAttribute(String data) {
+		if (data != null) {
+			EmployeeCategory employeeCategory = new EmployeeCategory();
+			employeeCategory.setName(data);
+			return employeeCategory;
+		}
+		return null;
+	}
+}

spring-orm/src/test/java/org/springframework/orm/jpa/domain/EmployeeKind.java

@@ -0,0 +1,29 @@
+/*
+ * 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.orm.jpa.domain;
+
+public class EmployeeKind {
+	private String name;
+
+	public String getName() {
+		return name;
+	}
+
+	public void setName(String name) {
+		this.name = name;
+	}
+}

spring-orm/src/test/java/org/springframework/orm/jpa/domain/EmployeeKindConverter.java

@@ -0,0 +1,40 @@
+/*
+ * 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.orm.jpa.domain;
+
+import jakarta.persistence.AttributeConverter;
+
+public class EmployeeKindConverter implements AttributeConverter<EmployeeKind, String> {
+
+	@Override
+	public String convertToDatabaseColumn(EmployeeKind employeeKind) {
+		if (employeeKind != null) {
+			return employeeKind.getName();
+		}
+		return null;
+	}
+
+	@Override
+	public EmployeeKind convertToEntityAttribute(String data) {
+		if (data != null) {
+			EmployeeKind employeeKind = new EmployeeKind();
+			employeeKind.setName(data);
+			return employeeKind;
+		}
+		return null;
+	}
+}

spring-orm/src/test/java/org/springframework/orm/jpa/persistenceunit/PersistenceManagedTypesBeanRegistrationAotProcessorTests.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.
@@ -40,7 +40,9 @@ import org.springframework.orm.jpa.JpaVendorAdapter;
 import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
 import org.springframework.orm.jpa.domain.DriversLicense;
 import org.springframework.orm.jpa.domain.Employee;
+import org.springframework.orm.jpa.domain.EmployeeCategoryConverter;
 import org.springframework.orm.jpa.domain.EmployeeId;
+import org.springframework.orm.jpa.domain.EmployeeKindConverter;
 import org.springframework.orm.jpa.domain.EmployeeLocation;
 import org.springframework.orm.jpa.domain.EmployeeLocationConverter;
 import org.springframework.orm.jpa.domain.Person;
@@ -96,8 +98,11 @@ class PersistenceManagedTypesBeanRegistrationAotProcessorTests {
 			assertThat(RuntimeHintsPredicates.reflection().onType(EmployeeId.class)
 					.withMemberCategories(MemberCategory.DECLARED_FIELDS)).accepts(hints);
 			assertThat(RuntimeHintsPredicates.reflection().onType(EmployeeLocationConverter.class)
-					.withMemberCategories(MemberCategory.INVOKE_DECLARED_CONSTRUCTORS, MemberCategory.INVOKE_PUBLIC_METHODS))
-					.accepts(hints);
+					.withMemberCategories(MemberCategory.INVOKE_DECLARED_CONSTRUCTORS)).accepts(hints);
+			assertThat(RuntimeHintsPredicates.reflection().onType(EmployeeCategoryConverter.class)
+					.withMemberCategories(MemberCategory.INVOKE_DECLARED_CONSTRUCTORS)).accepts(hints);
+			assertThat(RuntimeHintsPredicates.reflection().onType(EmployeeKindConverter.class)
+					.withMemberCategories(MemberCategory.INVOKE_DECLARED_CONSTRUCTORS)).accepts(hints);
 			assertThat(RuntimeHintsPredicates.reflection().onType(EmployeeLocation.class)
 					.withMemberCategories(MemberCategory.DECLARED_FIELDS)).accepts(hints);
 		});