com.bank.manager.configs.ContextCleanupListener.java Source code

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Here is the source code for com.bank.manager.configs.ContextCleanupListener.java

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/*
 * 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
 *
 *      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 com.bank.manager.configs;

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<String> 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);
                    }
                }
            }
        }
    }

}