Introduce @RegisterReflectionForBinding

This annotation and the related processor allows to
register reflection hints for data binding purpose
(class, fields, properties, record components for
the whole type hierarchy)

Closes gh-28979

Author: sdeleuze

spring-core/src/main/java/org/springframework/aot/hint/annotation/RegisterReflectionForBinding.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2002-2022 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.aot.hint.annotation;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+import org.springframework.core.annotation.AliasFor;
+
+/**
+ * Indicates that one or more {@link Class} reflection hints should be registered for
+ * data binding purpose (class, fields, properties, record components for the whole
+ * type hierarchy).
+ *
+ * <p>Typically used to annotate the bean class or bean method where the reflection hint
+ * is needed.
+ *
+ * @author Sebastien Deleuze
+ * @since 6.0
+ */
+@Target({ ElementType.TYPE, ElementType.METHOD })
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+@Reflective(RegisterReflectionForBindingProcessor.class)
+public @interface RegisterReflectionForBinding {
+
+	/**
+	 * Classes for which reflection hints should be registered to enable data binding
+	 * (class, fields, properties, record components for the whole type hierarchy).
+	 * @see #classes()
+	 */
+	@AliasFor("classes")
+	Class<?>[] value() default {};
+
+	/**
+	 * Classes for which reflection hints should be registered to enable data binding
+	 * (class, fields, properties, record components for the whole type hierarchy).
+	 * @see #value()
+	 */
+	@AliasFor("value")
+	Class<?>[] classes() default {};
+
+}

spring-core/src/main/java/org/springframework/aot/hint/annotation/RegisterReflectionForBindingProcessor.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2002-2022 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.aot.hint.annotation;
+
+import java.lang.reflect.AnnotatedElement;
+
+import org.springframework.aot.hint.ReflectionHints;
+import org.springframework.core.annotation.AnnotationUtils;
+
+/**
+ * A {@link ReflectiveProcessor} implementation that registers reflection hints
+ * for data binding purpose (class, constructors, fields, properties, record
+ * components for the whole type hierarchy).
+ *
+ * @author Sebastien Deleuze
+ * @since 6.0
+ */
+public class RegisterReflectionForBindingProcessor implements ReflectiveProcessor {
+
+	private final BindingReflectionHintsRegistrar bindingRegistrar = new BindingReflectionHintsRegistrar();
+
+	@Override
+	public void registerReflectionHints(ReflectionHints hints, AnnotatedElement element) {
+		RegisterReflectionForBinding registerReflection = AnnotationUtils.getAnnotation(element, RegisterReflectionForBinding.class);
+		if (registerReflection != null) {
+			for (Class<?> type : registerReflection.classes()) {
+				this.bindingRegistrar.registerReflectionHints(hints, type);
+			}
+		}
+	}
+}

spring-core/src/test/java/org/springframework/aot/hint/annotation/RegisterReflectionForBindingProcessorTests.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2002-2022 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.aot.hint.annotation;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.aot.hint.RuntimeHints;
+import org.springframework.aot.hint.predicate.RuntimeHintsPredicates;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link RegisterReflectionForBindingProcessor}.
+ *
+ * @author Sebastien Deleuze
+ */
+public class RegisterReflectionForBindingProcessorTests {
+
+	private final RegisterReflectionForBindingProcessor processor = new RegisterReflectionForBindingProcessor();
+
+	private final RuntimeHints hints = new RuntimeHints();
+
+	@Test
+	void registerReflectionForBindingOnClass() {
+		processor.registerReflectionHints(hints.reflection(), ClassLevelAnnotatedBean.class);
+		assertThat(RuntimeHintsPredicates.reflection().onType(SampleClassWithGetter.class)).accepts(hints);
+		assertThat(RuntimeHintsPredicates.reflection().onType(String.class)).accepts(hints);
+		assertThat(RuntimeHintsPredicates.reflection().onMethod(SampleClassWithGetter.class, "getName")).accepts(hints);
+	}
+
+	@Test
+	void registerReflectionForBindingOnMethod() throws NoSuchMethodException {
+		processor.registerReflectionHints(hints.reflection(), MethodLevelAnnotatedBean.class.getMethod("method"));
+		assertThat(RuntimeHintsPredicates.reflection().onType(SampleClassWithGetter.class)).accepts(hints);
+		assertThat(RuntimeHintsPredicates.reflection().onType(String.class)).accepts(hints);
+		assertThat(RuntimeHintsPredicates.reflection().onMethod(SampleClassWithGetter.class, "getName")).accepts(hints);
+	}
+
+	@RegisterReflectionForBinding(SampleClassWithGetter.class)
+	static class ClassLevelAnnotatedBean {
+	}
+
+	static class MethodLevelAnnotatedBean {
+
+		@RegisterReflectionForBinding(SampleClassWithGetter.class)
+		public void method() {
+		}
+	}
+
+	static class SampleClassWithGetter {
+
+		public String getName() {
+			return null;
+		}
+
+		public BindingReflectionHintsRegistrarTests.SampleEmptyClass unmanaged() {
+			return null;
+		}
+	}
+
+}