org.springframework.web.context.ContextCleanupListener Maven / Gradle / Ivy
/*
* Copyright 2002-2012 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
*
* https://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.web.context;
import java.util.Enumeration;
import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.DisposableBean;
/**
* Web application listener that cleans up remaining disposable attributes
* in the ServletContext, i.e. attributes which implement {@link DisposableBean}
* and haven't been removed before. This is typically used for destroying objects
* in "application" scope, for which the lifecycle implies destruction at the
* very end of the web application's shutdown phase.
*
* @author Juergen Hoeller
* @since 3.0
* @see org.springframework.web.context.support.ServletContextScope
* @see ContextLoaderListener
*/
public class ContextCleanupListener implements ServletContextListener {
private static final Log logger = LogFactory.getLog(ContextCleanupListener.class);
@Override
public void contextInitialized(ServletContextEvent event) {
}
@Override
public void contextDestroyed(ServletContextEvent event) {
cleanupAttributes(event.getServletContext());
}
/**
* Find all ServletContext attributes which implement {@link DisposableBean}
* and destroy them, removing all affected ServletContext attributes eventually.
* @param sc the ServletContext to check
*/
static void cleanupAttributes(ServletContext sc) {
Enumeration attrNames = sc.getAttributeNames();
while (attrNames.hasMoreElements()) {
String attrName = attrNames.nextElement();
if (attrName.startsWith("org.springframework.")) {
Object attrValue = sc.getAttribute(attrName);
if (attrValue instanceof DisposableBean) {
try {
((DisposableBean) attrValue).destroy();
}
catch (Throwable ex) {
logger.error("Couldn't invoke destroy method of attribute with name '" + attrName + "'", ex);
}
}
}
}
}
}