/**
* Recursively collect all declared {@code @Import} values. Unlike most meta-annotations it is
* valid to have several {@code @Import}s declared with different values; the usual process of
* returning values from the first meta-annotation on a class is not sufficient.
*
* <p>For example, it is common for a {@code @Configuration} class to declare direct
* {@code @Import}s in addition to meta-imports originating from an {@code @Enable} annotation.
*
* @param sourceClass the class to search
* @param imports the imports collected so far
* @param visited used to track visited classes to prevent infinite recursion
* @throws IOException if there is any problem reading metadata from the named class
*/
private void collectImports(
SourceClass sourceClass, Set<SourceClass> imports, Set<SourceClass> visited)
throws IOException {
if (visited.add(sourceClass)) {
for (SourceClass annotation : sourceClass.getAnnotations()) {
String annName = annotation.getMetadata().getClassName();
if (!annName.startsWith("java") && !annName.equals(Import.class.getName())) {
collectImports(annotation, imports, visited);
}
}
imports.addAll(sourceClass.getAnnotationAttributes(Import.class.getName(), "value"));
}
}
/**
* Register member (nested) classes that happen to be configuration classes themselves.
*
* @param sourceClass the source class to process
* @throws IOException if there is any problem reading metadata from a member class
*/
private void processMemberClasses(ConfigurationClass configClass, SourceClass sourceClass)
throws IOException {
for (SourceClass memberClass : sourceClass.getMemberClasses()) {
if (ConfigurationClassUtils.isConfigurationCandidate(memberClass.getMetadata())
&& !memberClass
.getMetadata()
.getClassName()
.equals(configClass.getMetadata().getClassName())) {
if (this.importStack.contains(configClass)) {
this.problemReporter.error(new CircularImportProblem(configClass, this.importStack));
} else {
this.importStack.push(configClass);
try {
processConfigurationClass(memberClass.asConfigClass(configClass));
} finally {
this.importStack.pop();
}
}
}
}
}
private void processImports(
ConfigurationClass configClass,
SourceClass currentSourceClass,
Collection<SourceClass> importCandidates,
boolean checkForCircularImports)
throws IOException {
if (importCandidates.isEmpty()) {
return;
}
if (checkForCircularImports && this.importStack.contains(configClass)) {
this.problemReporter.error(new CircularImportProblem(configClass, this.importStack));
} else {
this.importStack.push(configClass);
try {
for (SourceClass candidate : importCandidates) {
if (candidate.isAssignable(ImportSelector.class)) {
// Candidate class is an ImportSelector -> delegate to it to determine imports
Class<?> candidateClass = candidate.loadClass();
ImportSelector selector =
BeanUtils.instantiateClass(candidateClass, ImportSelector.class);
invokeAwareMethods(selector);
if (this.deferredImportSelectors != null
&& selector instanceof DeferredImportSelector) {
this.deferredImportSelectors.add(
new DeferredImportSelectorHolder(configClass, (DeferredImportSelector) selector));
} else {
String[] importClassNames = selector.selectImports(currentSourceClass.getMetadata());
Collection<SourceClass> importSourceClasses = asSourceClasses(importClassNames);
processImports(configClass, currentSourceClass, importSourceClasses, false);
}
} else if (candidate.isAssignable(ImportBeanDefinitionRegistrar.class)) {
// Candidate class is an ImportBeanDefinitionRegistrar ->
// delegate to it to register additional bean definitions
Class<?> candidateClass = candidate.loadClass();
ImportBeanDefinitionRegistrar registrar =
BeanUtils.instantiateClass(candidateClass, ImportBeanDefinitionRegistrar.class);
invokeAwareMethods(registrar);
configClass.addImportBeanDefinitionRegistrar(
registrar, currentSourceClass.getMetadata());
} else {
// Candidate class not an ImportSelector or ImportBeanDefinitionRegistrar ->
// process it as an @Configuration class
this.importStack.registerImport(
currentSourceClass.getMetadata(), candidate.getMetadata().getClassName());
processConfigurationClass(candidate.asConfigClass(configClass));
}
}
} catch (BeanDefinitionStoreException ex) {
throw ex;
} catch (Exception ex) {
throw new BeanDefinitionStoreException(
"Failed to process import candidates for configuration class ["
+ configClass.getMetadata().getClassName()
+ "]",
ex);
} finally {
this.importStack.pop();
}
}
}
/**
* Apply processing and build a complete {@link ConfigurationClass} by reading the annotations,
* members and methods from the source class. This method can be called multiple times as relevant
* sources are discovered.
*
* @param configClass the configuration class being build
* @param sourceClass a source class
* @return the superclass, or {@code null} if none found or previously processed
*/
protected final SourceClass doProcessConfigurationClass(
ConfigurationClass configClass, SourceClass sourceClass) throws IOException {
// Recursively process any member (nested) classes first
processMemberClasses(configClass, sourceClass);
// Process any @PropertySource annotations
for (AnnotationAttributes propertySource :
AnnotationConfigUtils.attributesForRepeatable(
sourceClass.getMetadata(),
PropertySources.class,
org.springframework.context.annotation.PropertySource.class)) {
if (this.environment instanceof ConfigurableEnvironment) {
processPropertySource(propertySource);
} else {
logger.warn(
"Ignoring @PropertySource annotation on ["
+ sourceClass.getMetadata().getClassName()
+ "]. Reason: Environment must implement ConfigurableEnvironment");
}
}
// Process any @ComponentScan annotations
Set<AnnotationAttributes> componentScans =
AnnotationConfigUtils.attributesForRepeatable(
sourceClass.getMetadata(), ComponentScans.class, ComponentScan.class);
if (!componentScans.isEmpty()
&& !this.conditionEvaluator.shouldSkip(
sourceClass.getMetadata(), ConfigurationPhase.REGISTER_BEAN)) {
for (AnnotationAttributes componentScan : componentScans) {
// The config class is annotated with @ComponentScan -> perform the scan immediately
Set<BeanDefinitionHolder> scannedBeanDefinitions =
this.componentScanParser.parse(componentScan, sourceClass.getMetadata().getClassName());
// Check the set of scanned definitions for any further config classes and parse recursively
// if necessary
for (BeanDefinitionHolder holder : scannedBeanDefinitions) {
if (ConfigurationClassUtils.checkConfigurationClassCandidate(
holder.getBeanDefinition(), this.metadataReaderFactory)) {
parse(holder.getBeanDefinition().getBeanClassName(), holder.getBeanName());
}
}
}
}
// Process any @Import annotations
processImports(configClass, sourceClass, getImports(sourceClass), true);
// Process any @ImportResource annotations
if (sourceClass.getMetadata().isAnnotated(ImportResource.class.getName())) {
AnnotationAttributes importResource =
AnnotationConfigUtils.attributesFor(sourceClass.getMetadata(), ImportResource.class);
String[] resources =
importResource.getAliasedStringArray("locations", ImportResource.class, sourceClass);
Class<? extends BeanDefinitionReader> readerClass = importResource.getClass("reader");
for (String resource : resources) {
String resolvedResource = this.environment.resolveRequiredPlaceholders(resource);
configClass.addImportedResource(resolvedResource, readerClass);
}
}
// Process individual @Bean methods
Set<MethodMetadata> beanMethods =
sourceClass.getMetadata().getAnnotatedMethods(Bean.class.getName());
for (MethodMetadata methodMetadata : beanMethods) {
configClass.addBeanMethod(new BeanMethod(methodMetadata, configClass));
}
// Process default methods on interfaces
for (SourceClass ifc : sourceClass.getInterfaces()) {
beanMethods = ifc.getMetadata().getAnnotatedMethods(Bean.class.getName());
for (MethodMetadata methodMetadata : beanMethods) {
if (!methodMetadata.isAbstract()) {
// A default method or other concrete method on a Java 8+ interface...
configClass.addBeanMethod(new BeanMethod(methodMetadata, configClass));
}
}
}
// Process superclass, if any
if (sourceClass.getMetadata().hasSuperClass()) {
String superclass = sourceClass.getMetadata().getSuperClassName();
if (!superclass.startsWith("java") && !this.knownSuperclasses.containsKey(superclass)) {
this.knownSuperclasses.put(superclass, configClass);
// Superclass found, return its annotation metadata and recurse
return sourceClass.getSuperClass();
}
}
// No superclass -> processing is complete
return null;
}
