package org.springframework.context.event;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.aop.framework.autoproxy.AutoProxyUtils;
import org.springframework.aop.scope.ScopedObject;
import org.springframework.aop.scope.ScopedProxyUtils;
import org.springframework.aop.support.AopUtils;
import org.springframework.beans.factory.BeanInitializationException;
import org.springframework.beans.factory.SmartInitializingSingleton;
import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.ApplicationListener;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.core.MethodIntrospector;
import org.springframework.core.SpringProperties;
import org.springframework.core.annotation.AnnotatedElementUtils;
import org.springframework.core.annotation.AnnotationAwareOrderComparator;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.lang.Nullable;
import org.springframework.stereotype.Component;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.CollectionUtils;
public class EventListenerMethodProcessor
implements SmartInitializingSingleton, ApplicationContextAware, BeanFactoryPostProcessor {
private static final boolean shouldIgnoreSpel = SpringProperties.getFlag("spring.spel.ignore");
protected final Log logger = LogFactory.getLog(getClass());
@Nullable
private ConfigurableApplicationContext applicationContext;
@Nullable
private ConfigurableListableBeanFactory beanFactory;
@Nullable
private List<EventListenerFactory> eventListenerFactories;
@Nullable
private final EventExpressionEvaluator evaluator;
private final Set<Class<?>> nonAnnotatedClasses = Collections.newSetFromMap(new ConcurrentHashMap<>(64));
public EventListenerMethodProcessor() {
if (shouldIgnoreSpel) {
this.evaluator = null;
}
else {
this.evaluator = new EventExpressionEvaluator();
}
}
@Override
public void setApplicationContext(ApplicationContext applicationContext) {
Assert.isTrue(applicationContext instanceof ConfigurableApplicationContext,
"ApplicationContext does not implement ConfigurableApplicationContext");
this.applicationContext = (ConfigurableApplicationContext) applicationContext;
}
@Override
public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) {
this.beanFactory = beanFactory;
Map<String, EventListenerFactory> beans = beanFactory.getBeansOfType(EventListenerFactory.class, false, false);
List<EventListenerFactory> factories = new ArrayList<>(beans.values());
AnnotationAwareOrderComparator.sort(factories);
this.eventListenerFactories = factories;
}
@Override
public void afterSingletonsInstantiated() {
ConfigurableListableBeanFactory beanFactory = this.beanFactory;
Assert.state(this.beanFactory != null, "No ConfigurableListableBeanFactory set");
String[] beanNames = beanFactory.getBeanNamesForType(Object.class);
for (String beanName : beanNames) {
if (!ScopedProxyUtils.isScopedTarget(beanName)) {
Class<?> type = null;
try {
type = AutoProxyUtils.determineTargetClass(beanFactory, beanName);
}
catch (Throwable ex) {
if (logger.isDebugEnabled()) {
logger.debug("Could not resolve target class for bean with name '" + beanName + "'", ex);
}
}
if (type != null) {
if (ScopedObject.class.isAssignableFrom(type)) {
try {
Class<?> targetClass = AutoProxyUtils.determineTargetClass(
beanFactory, ScopedProxyUtils.getTargetBeanName(beanName));
if (targetClass != null) {
type = targetClass;
}
}
catch (Throwable ex) {
if (logger.isDebugEnabled()) {
logger.debug("Could not resolve target bean for scoped proxy '" + beanName + "'", ex);
}
}
}
try {
processBean(beanName, type);
}
catch (Throwable ex) {
throw new BeanInitializationException("Failed to process @EventListener " +
"annotation on bean with name '" + beanName + "'", ex);
}
}
}
}
}
private void processBean(final String beanName, final Class<?> targetType) {
if (!this.nonAnnotatedClasses.contains(targetType) &&
AnnotationUtils.isCandidateClass(targetType, EventListener.class) &&
!isSpringContainerClass(targetType)) {
Map<Method, EventListener> annotatedMethods = null;
try {
annotatedMethods = MethodIntrospector.selectMethods(targetType,
(MethodIntrospector.MetadataLookup<EventListener>) method ->
AnnotatedElementUtils.findMergedAnnotation(method, EventListener.class));
}
catch (Throwable ex) {
if (logger.isDebugEnabled()) {
logger.debug("Could not resolve methods for bean with name '" + beanName + "'", ex);
}
}
if (CollectionUtils.isEmpty(annotatedMethods)) {
this.nonAnnotatedClasses.add(targetType);
if (logger.isTraceEnabled()) {
logger.trace("No @EventListener annotations found on bean class: " + targetType.getName());
}
}
else {
ConfigurableApplicationContext context = this.applicationContext;
Assert.state(context != null, "No ApplicationContext set");
List<EventListenerFactory> factories = this.eventListenerFactories;
Assert.state(factories != null, "EventListenerFactory List not initialized");
for (Method method : annotatedMethods.keySet()) {
for (EventListenerFactory factory : factories) {
if (factory.supportsMethod(method)) {
Method methodToUse = AopUtils.selectInvocableMethod(method, context.getType(beanName));
ApplicationListener<?> applicationListener =
factory.createApplicationListener(beanName, targetType, methodToUse);
if (applicationListener instanceof ApplicationListenerMethodAdapter) {
((ApplicationListenerMethodAdapter) applicationListener).init(context, this.evaluator);
}
context.addApplicationListener(applicationListener);
break;
}
}
}
if (logger.isDebugEnabled()) {
logger.debug(annotatedMethods.size() + " @EventListener methods processed on bean '" +
beanName + "': " + annotatedMethods);
}
}
}
}
private static boolean isSpringContainerClass(Class<?> clazz) {
return (clazz.getName().startsWith("org.springframework.") &&
!AnnotatedElementUtils.isAnnotated(ClassUtils.getUserClass(clazz), Component.class));
}
}