org.springframework.context.annotation.ConfigurationClassUtils Maven / Gradle / Ivy
/*
* Copyright 2002-2015 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
*
* http://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.context.annotation;
import java.io.IOException;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.annotation.AnnotatedBeanDefinition;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.support.AbstractBeanDefinition;
import org.springframework.core.Conventions;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.core.annotation.Order;
import org.springframework.core.type.AnnotationMetadata;
import org.springframework.core.type.StandardAnnotationMetadata;
import org.springframework.core.type.classreading.MetadataReader;
import org.springframework.core.type.classreading.MetadataReaderFactory;
import org.springframework.stereotype.Component;
/**
* Utilities for processing @{@link Configuration} classes.
*
* @author Chris Beams
* @author Juergen Hoeller
* @since 3.1
*/
abstract class ConfigurationClassUtils {
private static final String CONFIGURATION_CLASS_FULL = "full";
private static final String CONFIGURATION_CLASS_LITE = "lite";
private static final String CONFIGURATION_CLASS_ATTRIBUTE =
Conventions.getQualifiedAttributeName(ConfigurationClassPostProcessor.class, "configurationClass");
private static final String ORDER_ATTRIBUTE =
Conventions.getQualifiedAttributeName(ConfigurationClassPostProcessor.class, "order");
private static final Log logger = LogFactory.getLog(ConfigurationClassUtils.class);
private static final Set candidateIndicators = new HashSet(4);
static {
candidateIndicators.add(Component.class.getName());
candidateIndicators.add(ComponentScan.class.getName());
candidateIndicators.add(Import.class.getName());
candidateIndicators.add(ImportResource.class.getName());
}
/**
* Check whether the given bean definition is a candidate for a configuration class
* (or a nested component class declared within a configuration/component class,
* to be auto-registered as well), and mark it accordingly.
* @param beanDef the bean definition to check
* @param metadataReaderFactory the current factory in use by the caller
* @return whether the candidate qualifies as (any kind of) configuration class
*/
public static boolean checkConfigurationClassCandidate(BeanDefinition beanDef, MetadataReaderFactory metadataReaderFactory) {
String className = beanDef.getBeanClassName();
if (className == null) {
return false;
}
AnnotationMetadata metadata;
if (beanDef instanceof AnnotatedBeanDefinition &&
className.equals(((AnnotatedBeanDefinition) beanDef).getMetadata().getClassName())) {
// Can reuse the pre-parsed metadata from the given BeanDefinition...
metadata = ((AnnotatedBeanDefinition) beanDef).getMetadata();
}
else if (beanDef instanceof AbstractBeanDefinition && ((AbstractBeanDefinition) beanDef).hasBeanClass()) {
// Check already loaded Class if present...
// since we possibly can't even load the class file for this Class.
Class beanClass = ((AbstractBeanDefinition) beanDef).getBeanClass();
metadata = new StandardAnnotationMetadata(beanClass, true);
}
else {
try {
MetadataReader metadataReader = metadataReaderFactory.getMetadataReader(className);
metadata = metadataReader.getAnnotationMetadata();
}
catch (IOException ex) {
if (logger.isDebugEnabled()) {
logger.debug("Could not find class file for introspecting configuration annotations: " + className, ex);
}
return false;
}
}
if (isFullConfigurationCandidate(metadata)) {
beanDef.setAttribute(CONFIGURATION_CLASS_ATTRIBUTE, CONFIGURATION_CLASS_FULL);
}
else if (isLiteConfigurationCandidate(metadata)) {
beanDef.setAttribute(CONFIGURATION_CLASS_ATTRIBUTE, CONFIGURATION_CLASS_LITE);
}
else {
return false;
}
// It's a full or lite configuration candidate... Let's determine the order value, if any.
Map orderAttributes = metadata.getAnnotationAttributes(Order.class.getName());
if (orderAttributes != null) {
beanDef.setAttribute(ORDER_ATTRIBUTE, orderAttributes.get(AnnotationUtils.VALUE));
}
return true;
}
/**
* Check the given metadata for a configuration class candidate
* (or nested component class declared within a configuration/component class).
* @param metadata the metadata of the annotated class
* @return {@code true} if the given class is to be registered as a
* reflection-detected bean definition; {@code false} otherwise
*/
public static boolean isConfigurationCandidate(AnnotationMetadata metadata) {
return (isFullConfigurationCandidate(metadata) || isLiteConfigurationCandidate(metadata));
}
/**
* Check the given metadata for a full configuration class candidate
* (i.e. a class annotated with {@code @Configuration}).
* @param metadata the metadata of the annotated class
* @return {@code true} if the given class is to be processed as a full
* configuration class, including cross-method call interception
*/
public static boolean isFullConfigurationCandidate(AnnotationMetadata metadata) {
return metadata.isAnnotated(Configuration.class.getName());
}
/**
* Check the given metadata for a lite configuration class candidate
* (e.g. a class annotated with {@code @Component} or just having
* {@code @Import} declarations or {@code @Bean methods}).
* @param metadata the metadata of the annotated class
* @return {@code true} if the given class is to be processed as a lite
* configuration class, just registering it and scanning it for {@code @Bean} methods
*/
public static boolean isLiteConfigurationCandidate(AnnotationMetadata metadata) {
// Do not consider an interface or an annotation...
if (metadata.isInterface()) {
return false;
}
// Any of the typical annotations found?
for (String indicator : candidateIndicators) {
if (metadata.isAnnotated(indicator)) {
return true;
}
}
// Finally, let's look for @Bean methods...
try {
return metadata.hasAnnotatedMethods(Bean.class.getName());
}
catch (Throwable ex) {
if (logger.isDebugEnabled()) {
logger.debug("Failed to introspect @Bean methods on class [" + metadata.getClassName() + "]: " + ex);
}
return false;
}
}
/**
* Determine whether the given bean definition indicates a full {@code @Configuration}
* class, through checking {@link #checkConfigurationClassCandidate}'s metadata marker.
*/
public static boolean isFullConfigurationClass(BeanDefinition beanDef) {
return CONFIGURATION_CLASS_FULL.equals(beanDef.getAttribute(CONFIGURATION_CLASS_ATTRIBUTE));
}
/**
* Determine whether the given bean definition indicates a lite {@code @Configuration}
* class, through checking {@link #checkConfigurationClassCandidate}'s metadata marker.
*/
public static boolean isLiteConfigurationClass(BeanDefinition beanDef) {
return CONFIGURATION_CLASS_LITE.equals(beanDef.getAttribute(CONFIGURATION_CLASS_ATTRIBUTE));
}
/**
* Determine the order for the given configuration class bean definition,
* as set by {@link #checkConfigurationClassCandidate}.
* @param beanDef the bean definition to check
* @return the {@link @Order} annotation value on the configuration class,
* or {@link Ordered#LOWEST_PRECEDENCE} if none declared
* @since 4.2
*/
public static int getOrder(BeanDefinition beanDef) {
Integer order = (Integer) beanDef.getAttribute(ORDER_ATTRIBUTE);
return (order != null ? order : Ordered.LOWEST_PRECEDENCE);
}
}