Eliminate 2,870 lines of boilerplate using @Mixin annotation processor

.gitignore

@@ -56,3 +56,5 @@ cached-antora-playbook.yml
 
 node_modules
 /.kotlin/
+.ai/
+.junie/

build.gradle

@@ -12,6 +12,7 @@ plugins {
 ext {
 	moduleProjects = subprojects.findAll { it.name.startsWith("spring-") }
 	javaProjects = subprojects.findAll { !it.name.startsWith("framework-") }
+	mixinAnnotationVersion = "1.1.18"
 }
 
 description = "Spring Framework"

framework-annotation-processor/framework-annotation-processor.gradle

@@ -0,0 +1,3 @@
+plugins {
+    id("java")
+}

framework-annotation-processor/src/main/java/org/springframework/annotation/processor/NonProcessedAnnotationClaimer.java

@@ -0,0 +1,93 @@
+package org.springframework.annotation.processor;
+
+import javax.annotation.processing.*;
+import javax.lang.model.SourceVersion;
+import javax.lang.model.element.TypeElement;
+import java.util.Set;
+
+/**
+ * This annotation processor claims all the annotations that are not processed at compile time at all.
+ * Otherwise, the compiler would emit a warning that
+ * {@code No processor claimed any of these annotations}. Adding this to the compiler arg option {@code -Werror},
+ * would fail the build.
+ */
+@SupportedAnnotationTypes({
+		"com.fasterxml.jackson.annotation.JsonAnyGetter",
+		"com.fasterxml.jackson.annotation.JsonAnySetter",
+		"com.fasterxml.jackson.annotation.JsonInclude",
+		"com.fasterxml.jackson.annotation.JsonRootName",
+		"com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlProperty",
+		"com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlRootElement",
+		"com.oracle.svm.core.annotate.Alias",
+		"com.oracle.svm.core.annotate.Substitute",
+		"com.oracle.svm.core.annotate.TargetClass",
+		"jakarta.annotation.Generated",
+		"jakarta.servlet.annotation.HandlesTypes",
+		"javax.annotation.CheckForNull",
+		"javax.annotation.Nonnull",
+		"javax.annotation.meta.TypeQualifierDefault",
+		"javax.annotation.meta.TypeQualifierNickname",
+		"jdk.jfr/jdk.jfr.Category",
+		"jdk.jfr/jdk.jfr.Description",
+		"jdk.jfr/jdk.jfr.Enabled",
+		"jdk.jfr/jdk.jfr.Label",
+		"jdk.jfr/jdk.jfr.Registered",
+		"jdk.jfr/jdk.jfr.StackTrace",
+		"org.jspecify.annotations.NullMarked",
+		"org.jspecify.annotations.NullUnmarked",
+		"org.springframework.aot.hint.annotation.Reflective",
+		"org.springframework.aot.hint.annotation.RegisterReflection",
+		"org.springframework.beans.factory.annotation.Autowired",
+		"org.springframework.beans.factory.annotation.Qualifier",
+		"org.springframework.context.annotation.Bean",
+		"org.springframework.context.annotation.Conditional",
+		"org.springframework.context.annotation.Configuration",
+		"org.springframework.context.event.EventListener",
+		"org.springframework.context.annotation.Import",
+		"org.springframework.context.annotation.ImportRuntimeHints",
+		"org.springframework.context.annotation.Lazy",
+		"org.springframework.context.annotation.Role",
+		"org.springframework.context.annotation.Scope",
+		"org.springframework.core.annotation.AliasFor",
+		"org.springframework.core.annotation.Order",
+		"org.springframework.lang.CheckReturnValue",
+		"org.springframework.lang.Contract",
+		"org.springframework.messaging.handler.annotation.MessageMapping",
+		"org.springframework.stereotype.Component",
+		"org.springframework.stereotype.Controller",
+		"org.springframework.stereotype.Indexed",
+		"org.junit.jupiter.api.Test",
+		"org.junit.jupiter.api.BeforeEach",
+		"org.junit.jupiter.api.AfterEach",
+		"org.junit.jupiter.api.extension.RegisterExtension",
+		"org.junit.jupiter.api.extension.ExtendWith",
+		"org.junit.jupiter.params.ParameterizedTest",
+		"org.junit.jupiter.params.provider.MethodSource",
+		"org.springframework.test.annotation.Rollback",
+		"org.springframework.test.context.ContextConfiguration",
+		"org.springframework.test.context.bean.override.BeanOverride",
+		"org.springframework.test.context.web.WebAppConfiguration",
+		"org.springframework.transaction.annotation.Transactional",
+		"org.testng.annotations.AfterClass",
+		"org.testng.annotations.AfterMethod",
+		"org.testng.annotations.BeforeClass",
+		"org.testng.annotations.BeforeMethod",
+		"org.junit.runner.RunWith",
+		"jakarta.xml.bind.annotation.XmlRootElement",
+		"org.springframework.web.bind.annotation.ControllerAdvice",
+		"org.springframework.web.bind.annotation.ExceptionHandler",
+		"org.springframework.web.bind.annotation.Mapping",
+		"org.springframework.web.bind.annotation.RequestMapping",
+		"org.springframework.web.bind.annotation.ResponseBody",
+		"org.springframework.web.service.annotation.HttpExchange",
+		"tools.jackson.dataformat.xml.annotation.JacksonXmlProperty",
+})
+
+
+@SupportedSourceVersion(SourceVersion.RELEASE_21)
+public class NonProcessedAnnotationClaimer extends AbstractProcessor {
+	@Override
+	public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
+		return true;
+	}
+}

framework-annotation-processor/src/main/resources/META-INF/services/javax.annotation.processing.Processor

@@ -0,0 +1 @@
+org.springframework.annotation.processor.NonProcessedAnnotationClaimer

settings.gradle

@@ -28,6 +28,7 @@ include "framework-api"
 include "framework-bom"
 include "framework-docs"
 include "framework-platform"
+include 'framework-annotation-processor'
 include "integration-tests"
 
 rootProject.name = "spring"
@@ -50,3 +51,4 @@ settings.gradle.projectsLoaded {
 		}
 	}
 }
+

spring-beans/spring-beans.gradle

@@ -3,8 +3,11 @@ description = "Spring Beans"
 apply plugin: "kotlin"
 
 dependencies {
+    annotationProcessor project(":framework-annotation-processor")
 	api(project(":spring-core"))
-	optional("jakarta.inject:jakarta.inject-api")
+    compileOnly("guru.mocker.annotation:mixin-annotation:${mixinAnnotationVersion}")
+    annotationProcessor("guru.mocker.annotation:mixin-annotation-processor:${mixinAnnotationVersion}")
+    optional("jakarta.inject:jakarta.inject-api")
 	optional("org.apache.groovy:groovy-xml")
 	optional("org.jetbrains.kotlin:kotlin-reflect")
 	optional("org.jetbrains.kotlin:kotlin-stdlib")

spring-beans/src/main/java/org/springframework/beans/ExtendedBeanInfo.java

@@ -16,10 +16,7 @@
 
 package org.springframework.beans;
 
-import java.awt.Image;
-import java.beans.BeanDescriptor;
 import java.beans.BeanInfo;
-import java.beans.EventSetDescriptor;
 import java.beans.IndexedPropertyDescriptor;
 import java.beans.IntrospectionException;
 import java.beans.Introspector;
@@ -34,6 +31,7 @@
 import java.util.Set;
 import java.util.TreeSet;
 
+import guru.mocker.annotation.mixin.Mixin;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.jspecify.annotations.Nullable;
@@ -78,12 +76,11 @@
  * @see ExtendedBeanInfoFactory
  * @see CachedIntrospectionResults
  */
-class ExtendedBeanInfo implements BeanInfo {
+@Mixin
+class ExtendedBeanInfo extends ExtendedBeanInfoForwarder implements BeanInfo {
 
 	private static final Log logger = LogFactory.getLog(ExtendedBeanInfo.class);
 
-	private final BeanInfo delegate;
-
 	private final Set<PropertyDescriptor> propertyDescriptors = new TreeSet<>(new PropertyDescriptorComparator());
 
 
@@ -98,7 +95,7 @@ class ExtendedBeanInfo implements BeanInfo {
 	 * @see #getPropertyDescriptors()
 	 */
 	public ExtendedBeanInfo(BeanInfo delegate) {
-		this.delegate = delegate;
+		super(delegate);
 		for (PropertyDescriptor pd : delegate.getPropertyDescriptors()) {
 			try {
 				this.propertyDescriptors.add(pd instanceof IndexedPropertyDescriptor indexedPd ?
@@ -223,42 +220,6 @@ public PropertyDescriptor[] getPropertyDescriptors() {
 		return this.propertyDescriptors.toArray(PropertyDescriptorUtils.EMPTY_PROPERTY_DESCRIPTOR_ARRAY);
 	}
 
-	@Override
-	public BeanInfo[] getAdditionalBeanInfo() {
-		return this.delegate.getAdditionalBeanInfo();
-	}
-
-	@Override
-	public BeanDescriptor getBeanDescriptor() {
-		return this.delegate.getBeanDescriptor();
-	}
-
-	@Override
-	public int getDefaultEventIndex() {
-		return this.delegate.getDefaultEventIndex();
-	}
-
-	@Override
-	public int getDefaultPropertyIndex() {
-		return this.delegate.getDefaultPropertyIndex();
-	}
-
-	@Override
-	public EventSetDescriptor[] getEventSetDescriptors() {
-		return this.delegate.getEventSetDescriptors();
-	}
-
-	@Override
-	public Image getIcon(int iconKind) {
-		return this.delegate.getIcon(iconKind);
-	}
-
-	@Override
-	public MethodDescriptor[] getMethodDescriptors() {
-		return this.delegate.getMethodDescriptors();
-	}
-
-
 	/**
 	 * A simple {@link PropertyDescriptor}.
 	 */

spring-beans/src/main/java/org/springframework/beans/factory/aot/BeanRegistrationCodeFragmentsDecorator.java

@@ -16,17 +16,10 @@
 
 package org.springframework.beans.factory.aot;
 
-import java.util.List;
-import java.util.function.Predicate;
 import java.util.function.UnaryOperator;
 
-import org.springframework.aot.generate.GenerationContext;
-import org.springframework.aot.generate.MethodReference;
-import org.springframework.beans.factory.support.RegisteredBean;
-import org.springframework.beans.factory.support.RootBeanDefinition;
-import org.springframework.core.ResolvableType;
-import org.springframework.javapoet.ClassName;
-import org.springframework.javapoet.CodeBlock;
+import guru.mocker.annotation.mixin.Mixin;
+
 import org.springframework.util.Assert;
 
 /**
@@ -39,60 +32,12 @@
  * @author Stephane Nicoll
  * @since 6.0
  */
-public class BeanRegistrationCodeFragmentsDecorator implements BeanRegistrationCodeFragments {
-
-	private final BeanRegistrationCodeFragments delegate;
-
+@Mixin
+public class BeanRegistrationCodeFragmentsDecorator extends BeanRegistrationCodeFragmentsForwarder implements BeanRegistrationCodeFragments {
 
 	protected BeanRegistrationCodeFragmentsDecorator(BeanRegistrationCodeFragments delegate) {
+		super(delegate);
 		Assert.notNull(delegate, "Delegate must not be null");
-		this.delegate = delegate;
-	}
-
-	@Override
-	public ClassName getTarget(RegisteredBean registeredBean) {
-		return this.delegate.getTarget(registeredBean);
-	}
-
-	@Override
-	public CodeBlock generateNewBeanDefinitionCode(GenerationContext generationContext,
-			ResolvableType beanType, BeanRegistrationCode beanRegistrationCode) {
-
-		return this.delegate.generateNewBeanDefinitionCode(generationContext, beanType, beanRegistrationCode);
-	}
-
-	@Override
-	public CodeBlock generateSetBeanDefinitionPropertiesCode(
-			GenerationContext generationContext, BeanRegistrationCode beanRegistrationCode,
-			RootBeanDefinition beanDefinition, Predicate<String> attributeFilter) {
-
-		return this.delegate.generateSetBeanDefinitionPropertiesCode(
-				generationContext, beanRegistrationCode, beanDefinition, attributeFilter);
-	}
-
-	@Override
-	public CodeBlock generateSetBeanInstanceSupplierCode(
-			GenerationContext generationContext, BeanRegistrationCode beanRegistrationCode,
-			CodeBlock instanceSupplierCode, List<MethodReference> postProcessors) {
-
-		return this.delegate.generateSetBeanInstanceSupplierCode(generationContext,
-				beanRegistrationCode, instanceSupplierCode, postProcessors);
-	}
-
-	@Override
-	public CodeBlock generateInstanceSupplierCode(
-			GenerationContext generationContext, BeanRegistrationCode beanRegistrationCode,
-			boolean allowDirectSupplierShortcut) {
-
-		return this.delegate.generateInstanceSupplierCode(generationContext,
-				beanRegistrationCode, allowDirectSupplierShortcut);
-	}
-
-	@Override
-	public CodeBlock generateReturnCode(
-			GenerationContext generationContext, BeanRegistrationCode beanRegistrationCode) {
-
-		return this.delegate.generateReturnCode(generationContext, beanRegistrationCode);
 	}
 
 }