Support Java record for v1.6. Fixes #1830

Author: uc4w6c

springdoc-openapi-common/src/main/java/org/springdoc/core/MethodParameterPojoExtractor.java

@@ -25,9 +25,7 @@
 import java.beans.Introspector;
 import java.beans.PropertyDescriptor;
 import java.lang.annotation.Annotation;
-import java.lang.reflect.Field;
-import java.lang.reflect.Type;
-import java.lang.reflect.TypeVariable;
+import java.lang.reflect.*;
 import java.nio.charset.Charset;
 import java.time.Duration;
 import java.time.LocalTime;
@@ -175,17 +173,39 @@ private static Stream<MethodParameter> fromSimpleClass(Class<?> paramClass, Fiel
 		Annotation[] fieldAnnotations = field.getDeclaredAnnotations();
 		try {
 			Parameter parameter = field.getAnnotation(Parameter.class);
-			boolean isNotRequired  = parameter == null || !parameter.required();
+			boolean isNotRequired = parameter == null || !parameter.required();
 			Annotation[] finalFieldAnnotations = fieldAnnotations;
-			return Stream.of(Introspector.getBeanInfo(paramClass).getPropertyDescriptors())
-					.filter(d -> d.getName().equals(field.getName()))
-					.map(PropertyDescriptor::getReadMethod)
-					.filter(Objects::nonNull)
-					.map(method -> new MethodParameter(method, -1))
-					.map(methodParameter -> DelegatingMethodParameter.changeContainingClass(methodParameter, paramClass))
-					.map(param -> new DelegatingMethodParameter(param, fieldNamePrefix + field.getName(), finalFieldAnnotations, true, isNotRequired));
+
+			if ("java.lang.Record".equals(paramClass.getSuperclass().getName())) {
+				Method classGetRecordComponents = Class.class.getMethod("getRecordComponents");
+				Object[] components = (Object[]) classGetRecordComponents.invoke(paramClass);
+
+				Class<?> c = Class.forName("java.lang.reflect.RecordComponent");
+				Method recordComponentGetAccessor = c.getMethod("getAccessor");
+
+				List<Method> methods = new ArrayList<>();
+				for (Object object : components) {
+					methods.add((Method) recordComponentGetAccessor.invoke(object));
+				}
+				return methods.stream()
+						.filter(method -> method.getName().equals(field.getName()))
+						.map(method -> new MethodParameter(method, -1))
+						.map(methodParameter -> DelegatingMethodParameter.changeContainingClass(methodParameter, paramClass))
+						.map(param -> new DelegatingMethodParameter(param, fieldNamePrefix + field.getName(), finalFieldAnnotations, true, isNotRequired));
+
+			}
+			else
+				return Stream.of(Introspector.getBeanInfo(paramClass).getPropertyDescriptors())
+						.filter(d -> d.getName().equals(field.getName()))
+						.map(PropertyDescriptor::getReadMethod)
+						.filter(Objects::nonNull)
+						.map(method -> new MethodParameter(method, -1))
+						.map(methodParameter -> DelegatingMethodParameter.changeContainingClass(methodParameter, paramClass))
+						.map(param -> new DelegatingMethodParameter(param, fieldNamePrefix + field.getName(), finalFieldAnnotations, true, isNotRequired));
 		}
-		catch (IntrospectionException e) {
+		catch (IntrospectionException | NoSuchMethodException |
+			   InvocationTargetException | IllegalAccessException |
+			   ClassNotFoundException e) {
 			return Stream.of();
 		}
 	}

springdoc-openapi-common/src/test/java/org/springdoc/core/MethodParameterPojoExtractorTest.java

@@ -0,0 +1,122 @@
+/*
+ *
+ *  *
+ *  *  *
+ *  *  *  * Copyright 2019-2022 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.springdoc.core;
+
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.EnabledForJreRange;
+import org.junit.jupiter.api.condition.JRE;
+import org.junit.jupiter.api.io.TempDir;
+
+import org.springframework.core.MethodParameter;
+
+import javax.tools.JavaCompiler;
+import javax.tools.ToolProvider;
+
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.lang.reflect.Method;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.util.stream.Stream;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link MethodParameterPojoExtractor}.
+ */
+class MethodParameterPojoExtractorTest {
+	@TempDir
+	File tempDir;
+
+	/**
+	 * Tests for {@link MethodParameterPojoExtractor#extractFrom(Class<?>)}.
+	 */
+	@Nested
+	class extractFrom {
+		@Test
+		@EnabledForJreRange(min = JRE.JAVA_17)
+		void ifRecordObjectShouldGetField() throws IOException, ClassNotFoundException {
+			File recordObject = new File(tempDir, "RecordObject.java");
+			try (PrintWriter writer = new PrintWriter(new FileWriter(recordObject))) {
+				writer.println("public record RecordObject(String email, String firstName, String lastName){");
+				writer.println("}");
+			}
+			String[] args = {
+					recordObject.getAbsolutePath()
+			};
+			JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
+			int r = compiler.run(null, null, null, args);
+			if (r != 0) {
+				throw new IllegalStateException("Compilation failed");
+			}
+			URL[] urls = { tempDir.toURI().toURL() };
+			ClassLoader loader = URLClassLoader.newInstance(urls);
+
+			Class<?> clazz = loader.loadClass("RecordObject");
+
+			Stream<MethodParameter> actual = MethodParameterPojoExtractor.extractFrom(clazz);
+			assertThat(actual)
+					.extracting(MethodParameter::getMethod)
+					.extracting(Method::getName)
+					.containsOnlyOnce("email", "firstName", "lastName");
+		}
+
+		@Test
+		void ifRecordObjectShouldGetMethod() {
+			Stream<MethodParameter> actual = MethodParameterPojoExtractor.extractFrom(ClassObject.class);
+			assertThat(actual)
+					.extracting(MethodParameter::getMethod)
+					.extracting(Method::getName)
+					.containsOnlyOnce("getEmail", "getFirstName", "getLastName");
+		}
+
+		public class ClassObject {
+			private String email;
+
+			private String firstName;
+
+			private String lastName;
+
+			public ClassObject(String email, String firstName, String lastName) {
+				this.email = email;
+				this.firstName = firstName;
+				this.lastName = lastName;
+			}
+
+			public String getEmail() {
+				return email;
+			}
+
+			public String getFirstName() {
+				return firstName;
+			}
+
+			public String getLastName() {
+				return lastName;
+			}
+		}
+	}
+}