Add support for serialization in RequestMappingReflectiveProcessor

Support reflection-based serialization of parameters annotated
with @RequestBody and return values annotated with @ResponseBody.

It leverages a new BindingReflectionHintsRegistrar class that
is designed to register transitively the types usually needed
for binding and reflection-based serialization on fields,
constructors and properties. Generics are taken in account
as well.

Closes gh-28518

spring-core/src/test/java/org/springframework/aot/hint/support/BindingReflectionHintsRegistrarTests.java

@@ -0,0 +1,174 @@
+/*
+ * 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.support;
+
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.aot.hint.ExecutableMode;
+import org.springframework.aot.hint.MemberCategory;
+import org.springframework.aot.hint.RuntimeHints;
+import org.springframework.aot.hint.TypeReference;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link BindingReflectionHintsRegistrar}.
+ *
+ * @author Sebastien Deleuze
+ */
+public class BindingReflectionHintsRegistrarTests {
+
+	private final BindingReflectionHintsRegistrar bindingRegistrar = new BindingReflectionHintsRegistrar();
+	private final RuntimeHints hints = new RuntimeHints();
+
+	@Test
+	void registerTypeForSerializationWithEmptyClass() {
+		bindingRegistrar.registerReflectionHints(this.hints.reflection(), SampleEmptyClass.class);
+		assertThat(this.hints.reflection().typeHints()).singleElement()
+				.satisfies(typeHint -> {
+					assertThat(typeHint.getType()).isEqualTo(TypeReference.of(SampleEmptyClass.class));
+					assertThat(typeHint.getMemberCategories()).containsExactlyInAnyOrder(
+							MemberCategory.DECLARED_FIELDS, MemberCategory.INVOKE_DECLARED_CONSTRUCTORS);
+					assertThat(typeHint.constructors()).isEmpty();
+					assertThat(typeHint.fields()).isEmpty();
+					assertThat(typeHint.methods()).isEmpty();
+				});
+	}
+
+	@Test
+	void registerTypeForSerializationWithNoProperty() {
+		bindingRegistrar.registerReflectionHints(this.hints.reflection(), SampleClassWithNoProperty.class);
+		assertThat(this.hints.reflection().typeHints()).singleElement()
+				.satisfies(typeHint -> assertThat(typeHint.getType()).isEqualTo(TypeReference.of(SampleClassWithNoProperty.class)));
+	}
+
+	@Test
+	void registerTypeForSerializationWithGetter() {
+		bindingRegistrar.registerReflectionHints(this.hints.reflection(), SampleClassWithGetter.class);
+		assertThat(this.hints.reflection().typeHints()).satisfiesExactlyInAnyOrder(
+				typeHint -> {
+					assertThat(typeHint.getType()).isEqualTo(TypeReference.of(String.class));
+					assertThat(typeHint.getMemberCategories()).isEmpty();
+					assertThat(typeHint.constructors()).isEmpty();
+					assertThat(typeHint.fields()).isEmpty();
+					assertThat(typeHint.methods()).isEmpty();
+				},
+				typeHint -> {
+					assertThat(typeHint.getType()).isEqualTo(TypeReference.of(SampleClassWithGetter.class));
+					assertThat(typeHint.methods()).singleElement().satisfies(methodHint -> {
+						assertThat(methodHint.getName()).isEqualTo("getName");
+						assertThat(methodHint.getModes()).containsOnly(ExecutableMode.INVOKE);
+					});
+				});
+	}
+
+	@Test
+	void registerTypeForSerializationWithSetter() {
+		bindingRegistrar.registerReflectionHints(this.hints.reflection(), SampleClassWithSetter.class);
+		assertThat(this.hints.reflection().typeHints()).satisfiesExactlyInAnyOrder(
+				typeHint -> {
+					assertThat(typeHint.getType()).isEqualTo(TypeReference.of(String.class));
+					assertThat(typeHint.getMemberCategories()).isEmpty();
+					assertThat(typeHint.constructors()).isEmpty();
+					assertThat(typeHint.fields()).isEmpty();
+					assertThat(typeHint.methods()).isEmpty();
+				},
+				typeHint -> {
+					assertThat(typeHint.getType()).isEqualTo(TypeReference.of(SampleClassWithSetter.class));
+					assertThat(typeHint.methods()).singleElement().satisfies(methodHint -> {
+						assertThat(methodHint.getName()).isEqualTo("setName");
+						assertThat(methodHint.getModes()).containsOnly(ExecutableMode.INVOKE);
+					});
+				});
+	}
+
+	@Test
+	void registerTypeForSerializationWithListProperty() {
+		bindingRegistrar.registerReflectionHints(this.hints.reflection(), SampleClassWithListProperty.class);
+		assertThat(this.hints.reflection().typeHints()).satisfiesExactlyInAnyOrder(
+				typeHint -> {
+					assertThat(typeHint.getType()).isEqualTo(TypeReference.of(String.class));
+					assertThat(typeHint.getMemberCategories()).isEmpty();
+					assertThat(typeHint.constructors()).isEmpty();
+					assertThat(typeHint.fields()).isEmpty();
+					assertThat(typeHint.methods()).isEmpty();
+				},
+				typeHint -> {
+					assertThat(typeHint.getType()).isEqualTo(TypeReference.of(List.class));
+					assertThat(typeHint.getMemberCategories()).isEmpty();
+					assertThat(typeHint.constructors()).isEmpty();
+					assertThat(typeHint.fields()).isEmpty();
+					assertThat(typeHint.methods()).isEmpty();
+				},
+				typeHint -> {
+					assertThat(typeHint.getType()).isEqualTo(TypeReference.of(SampleClassWithListProperty.class));
+					assertThat(typeHint.methods()).satisfiesExactlyInAnyOrder(
+							methodHint -> {
+								assertThat(methodHint.getName()).isEqualTo("setNames");
+								assertThat(methodHint.getModes()).containsOnly(ExecutableMode.INVOKE);
+							},
+							methodHint -> {
+								assertThat(methodHint.getName()).isEqualTo("getNames");
+								assertThat(methodHint.getModes()).containsOnly(ExecutableMode.INVOKE);
+							});
+				});
+	}
+
+	static class SampleEmptyClass {
+	}
+
+	static class SampleClassWithNoProperty {
+
+		String name() {
+			return null;
+		}
+	}
+
+	static class SampleClassWithGetter {
+
+		public String getName() {
+			return null;
+		}
+
+		public SampleEmptyClass unmanaged() {
+			return null;
+		}
+	}
+
+	static class SampleClassWithSetter {
+
+		public void setName(String name) {
+		}
+
+		public SampleEmptyClass unmanaged() {
+			return null;
+		}
+	}
+
+	static class SampleClassWithListProperty {
+
+		public List<String> getNames() {
+			return null;
+		}
+
+		public void setNames(List<String> names) {
+		}
+	}
+
+}