org.springframework.context.event.GenericApplicationListenerAdapter Maven / Gradle / Ivy
/*
* Copyright 2002-2016 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.event;
import org.springframework.aop.support.AopUtils;
import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationListener;
import org.springframework.core.Ordered;
import org.springframework.core.ResolvableType;
import org.springframework.util.Assert;
/**
* {@link GenericApplicationListener} adapter that determines supported event types
* through introspecting the generically declared type of the target listener.
*
* @author Juergen Hoeller
* @author Stephane Nicoll
* @since 3.0
* @see org.springframework.context.ApplicationListener#onApplicationEvent
*/
public class GenericApplicationListenerAdapter implements GenericApplicationListener, SmartApplicationListener {
private final ApplicationListener delegate;
private final ResolvableType declaredEventType;
/**
* Create a new GenericApplicationListener for the given delegate.
* @param delegate the delegate listener to be invoked
*/
@SuppressWarnings("unchecked")
public GenericApplicationListenerAdapter(ApplicationListener delegate) {
Assert.notNull(delegate, "Delegate listener must not be null");
this.delegate = (ApplicationListener) delegate;
this.declaredEventType = resolveDeclaredEventType(this.delegate);
}
@Override
public void onApplicationEvent(ApplicationEvent event) {
this.delegate.onApplicationEvent(event);
}
@Override
@SuppressWarnings("unchecked")
public boolean supportsEventType(ResolvableType eventType) {
if (this.delegate instanceof SmartApplicationListener) {
Class eventClass = (Class) eventType.resolve();
return (eventClass != null && ((SmartApplicationListener) this.delegate).supportsEventType(eventClass));
}
else {
return (this.declaredEventType == null || this.declaredEventType.isAssignableFrom(eventType));
}
}
@Override
public boolean supportsEventType(Class eventType) {
return supportsEventType(ResolvableType.forClass(eventType));
}
@Override
public boolean supportsSourceType(Class sourceType) {
if (this.delegate instanceof SmartApplicationListener) {
return ((SmartApplicationListener) this.delegate).supportsSourceType(sourceType);
}
else {
return true;
}
}
@Override
public int getOrder() {
return (this.delegate instanceof Ordered ? ((Ordered) this.delegate).getOrder() : Ordered.LOWEST_PRECEDENCE);
}
static ResolvableType resolveDeclaredEventType(Class listenerType) {
ResolvableType resolvableType = ResolvableType.forClass(listenerType).as(ApplicationListener.class);
if (resolvableType == null || !resolvableType.hasGenerics()) {
return null;
}
return resolvableType.getGeneric();
}
private static ResolvableType resolveDeclaredEventType(ApplicationListener listener) {
ResolvableType declaredEventType = resolveDeclaredEventType(listener.getClass());
if (declaredEventType == null || declaredEventType.isAssignableFrom(
ResolvableType.forClass(ApplicationEvent.class))) {
Class targetClass = AopUtils.getTargetClass(listener);
if (targetClass != listener.getClass()) {
declaredEventType = resolveDeclaredEventType(targetClass);
}
}
return declaredEventType;
}
}