Support for pre-generated CGLIB proxy classes (in AOT scenarios)

Includes runtime storing of generated classes to a directory specified by the "cglib.generatedClasses" system property. Avoids lazy CGLIB fast-class generation and replaces generated Enhancer and MethodWrapper key classes with equivalent record types. Introduces support for early type determination in InstantiationStrategy, AopProxy and SmartInstantiationAwareBeanPostProcessor - in order to trigger CGLIB class generation in refreshForAotProcessing (through early determineBeanType calls for bean definitions).

Closes gh-28115

spring-context/src/main/java/org/springframework/context/annotation/ClassPathScanningCandidateComponentProvider.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * 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.
@@ -422,6 +422,11 @@ public class ClassPathScanningCandidateComponentProvider implements EnvironmentC
 			boolean traceEnabled = logger.isTraceEnabled();
 			boolean debugEnabled = logger.isDebugEnabled();
 			for (Resource resource : resources) {
+				String filename = resource.getFilename();
+				if (filename != null && filename.contains(ClassUtils.CGLIB_CLASS_SEPARATOR)) {
+					// Ignore CGLIB-generated classes in the classpath
+					continue;
+				}
 				if (traceEnabled) {
 					logger.trace("Scanning " + resource);
 				}

spring-context/src/main/java/org/springframework/context/annotation/ConfigurationClassEnhancer.java

@@ -123,6 +123,7 @@ class ConfigurationClassEnhancer {
 		enhancer.setInterfaces(new Class<?>[] {EnhancedConfiguration.class});
 		enhancer.setUseFactory(false);
 		enhancer.setNamingPolicy(SpringNamingPolicy.INSTANCE);
+		enhancer.setAttemptLoad(true);
 		enhancer.setStrategy(new BeanFactoryAwareGeneratorStrategy(classLoader));
 		enhancer.setCallbackFilter(CALLBACK_FILTER);
 		enhancer.setCallbackTypes(CALLBACK_FILTER.getCallbackTypes());
@@ -508,6 +509,7 @@ class ConfigurationClassEnhancer {
 			Enhancer enhancer = new Enhancer();
 			enhancer.setSuperclass(factoryBean.getClass());
 			enhancer.setNamingPolicy(SpringNamingPolicy.INSTANCE);
+			enhancer.setAttemptLoad(true);
 			enhancer.setCallbackType(MethodInterceptor.class);
 
 			// Ideally create enhanced FactoryBean proxy without constructor side effects,

spring-context/src/main/java/org/springframework/context/annotation/ConfigurationClassPostProcessor.java

@@ -64,7 +64,6 @@ import org.springframework.context.ApplicationStartupAware;
 import org.springframework.context.EnvironmentAware;
 import org.springframework.context.ResourceLoaderAware;
 import org.springframework.context.annotation.ConfigurationClassEnhancer.EnhancedConfiguration;
-import org.springframework.core.NativeDetector;
 import org.springframework.core.Ordered;
 import org.springframework.core.PriorityOrdered;
 import org.springframework.core.env.Environment;
@@ -286,11 +285,8 @@ public class ConfigurationClassPostProcessor implements BeanDefinitionRegistryPo
 	}
 
 	@Override
-	public BeanFactoryInitializationAotContribution processAheadOfTime(
-			ConfigurableListableBeanFactory beanFactory) {
-
-		return (beanFactory.containsBean(IMPORT_REGISTRY_BEAN_NAME)
-				? new AotContribution(beanFactory) : null);
+	public BeanFactoryInitializationAotContribution processAheadOfTime(ConfigurableListableBeanFactory beanFactory) {
+		return (beanFactory.containsBean(IMPORT_REGISTRY_BEAN_NAME) ? new AotContribution(beanFactory) : null);
 	}
 
 	/**
@@ -452,7 +448,7 @@ public class ConfigurationClassPostProcessor implements BeanDefinitionRegistryPo
 				configBeanDefs.put(beanName, abd);
 			}
 		}
-		if (configBeanDefs.isEmpty() || NativeDetector.inNativeImage()) {
+		if (configBeanDefs.isEmpty()) {
 			// nothing to enhance -> return immediately
 			enhanceConfigClasses.end();
 			return;
@@ -514,8 +510,8 @@ public class ConfigurationClassPostProcessor implements BeanDefinitionRegistryPo
 
 		private static final String BEAN_FACTORY_VARIABLE = BeanFactoryInitializationCode.BEAN_FACTORY_VARIABLE;
 
-		private static final ParameterizedTypeName STRING_STRING_MAP = ParameterizedTypeName
-				.get(Map.class, String.class, String.class);
+		private static final ParameterizedTypeName STRING_STRING_MAP =
+				ParameterizedTypeName.get(Map.class, String.class, String.class);
 
 		private static final String MAPPINGS_VARIABLE = "mappings";
 
@@ -523,15 +519,12 @@ public class ConfigurationClassPostProcessor implements BeanDefinitionRegistryPo
 
 		private static final String BEAN_NAME = "org.springframework.context.annotation.internalImportAwareAotProcessor";
 
-
 		private final ConfigurableListableBeanFactory beanFactory;
 
-
 		public AotContribution(ConfigurableListableBeanFactory beanFactory) {
 			this.beanFactory = beanFactory;
 		}
 
-
 		@Override
 		public void applyTo(GenerationContext generationContext,
 				BeanFactoryInitializationCode beanFactoryInitializationCode) {
@@ -550,11 +543,8 @@ public class ConfigurationClassPostProcessor implements BeanDefinitionRegistryPo
 			}
 		}
 
-		private void generateAddPostProcessorMethod(MethodSpec.Builder method,
-				Map<String, String> mappings) {
-
-			method.addJavadoc(
-					"Add ImportAwareBeanPostProcessor to support ImportAware beans");
+		private void generateAddPostProcessorMethod(MethodSpec.Builder method, Map<String, String> mappings) {
+			method.addJavadoc("Add ImportAwareBeanPostProcessor to support ImportAware beans");
 			method.addModifiers(Modifier.PRIVATE);
 			method.addParameter(DefaultListableBeanFactory.class, BEAN_FACTORY_VARIABLE);
 			method.addCode(generateAddPostProcessorCode(mappings));

spring-context/src/main/java/org/springframework/context/support/GenericApplicationContext.java

@@ -18,6 +18,7 @@ package org.springframework.context.support;
 
 import java.io.IOException;
 import java.lang.reflect.Constructor;
+import java.util.List;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.Supplier;
 
@@ -29,6 +30,7 @@ import org.springframework.beans.factory.config.AutowireCapableBeanFactory;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.config.BeanDefinitionCustomizer;
 import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
+import org.springframework.beans.factory.config.SmartInstantiationAwareBeanPostProcessor;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
 import org.springframework.beans.factory.support.BeanDefinitionRegistryPostProcessor;
 import org.springframework.beans.factory.support.DefaultListableBeanFactory;
@@ -408,8 +410,29 @@ public class GenericApplicationContext extends AbstractApplicationContext implem
 		invokeBeanFactoryPostProcessors(this.beanFactory);
 		this.beanFactory.freezeConfiguration();
 		PostProcessorRegistrationDelegate.invokeMergedBeanDefinitionPostProcessors(this.beanFactory);
+		preDetermineBeanTypes();
 	}
 
+	/**
+	 * Pre-determine bean types in order to trigger early proxy class creation.
+	 * @see org.springframework.beans.factory.BeanFactory#getType
+	 * @see SmartInstantiationAwareBeanPostProcessor#determineBeanType
+	 */
+	private void preDetermineBeanTypes() {
+		List<SmartInstantiationAwareBeanPostProcessor> bpps =
+				PostProcessorRegistrationDelegate.loadBeanPostProcessors(
+						this.beanFactory, SmartInstantiationAwareBeanPostProcessor.class);
+		for (String beanName : this.beanFactory.getBeanDefinitionNames()) {
+			Class<?> beanType = this.beanFactory.getType(beanName);
+			if (beanType != null) {
+				for (SmartInstantiationAwareBeanPostProcessor bpp : bpps) {
+					beanType = bpp.determineBeanType(beanType, beanName);
+				}
+			}
+		}
+	}
+
+
 	//---------------------------------------------------------------------
 	// Convenient methods for registering individual beans
 	//---------------------------------------------------------------------