Struts example source code file (ActionContextCleanUp.java)

This example Struts source code file (ActionContextCleanUp.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Struts tags/keywords

actioncontextcleanup_dofilter, filterchain, http, httpservletrequest, httpservletresponse, httpservletresponse, integer, integer, io, ioexception, logger, request, response, servlet, servletexception, servletexception, servletresponse, string, string

The Struts ActionContextCleanUp.java source code

/*
 * $Id: ActionContextCleanUp.java 674498 2008-07-07 14:10:42Z mrdon $
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.struts2.dispatcher;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.util.logging.Logger;
import com.opensymphony.xwork2.util.logging.LoggerFactory;
import com.opensymphony.xwork2.util.profiling.UtilTimerStack;

/**
 * <!-- SNIPPET START: description -->
 * Special filter designed to work with the {@link FilterDispatcher} and allow
 * for easier integration with SiteMesh. Normally, ordering your filters to have
 * SiteMesh go first, and then {@link FilterDispatcher} go second is perfectly fine.
 * However, sometimes you may wish to access Struts features, including the
 * value stack, from within your SiteMesh decorators. Because {@link FilterDispatcher}
 * cleans up the {@link ActionContext}, your decorator won't have access to the
 * data you want.
 * <p/>
 * <p/>
 * By adding this filter, the {@link FilterDispatcher} will know to not clean up and
 * instead defer cleanup to this filter. The ordering of the filters should then be:
 * <p/>
 * <ul>
 * <li>this filter
 * <li>SiteMesh filter
 * <li>{@link FilterDispatcher}
 * </ul>
 * <!-- SNIPPET END: description -->
 *
 *
 * @deprecated Since Struts 2.1.3, use {@link org.apache.struts2.dispatcher.ng.filter.StrutsPrepareFilter} and
 * {@link org.apache.struts2.dispatcher.ng.filter.StrutsExecuteFilter} to use other Servlet filters that need access to
 * the ActionContext
 * @see FilterDispatcher
 * @see Dispatcher
 * @see org.apache.struts2.dispatcher.ng.filter.StrutsPrepareFilter
 * @see org.apache.struts2.dispatcher.ng.filter.StrutsExecuteFilter
 *
 * @version $Date: 2008-07-07 16:10:42 +0200 (Mon, 07 Jul 2008) $ $Id: ActionContextCleanUp.java 674498 2008-07-07 14:10:42Z mrdon $
 */
public class ActionContextCleanUp implements Filter {

    private static final Logger LOG = LoggerFactory.getLogger(ActionContextCleanUp.class);

    private static final String COUNTER = "__cleanup_recursion_counter";

    /**
     * @see javax.servlet.Filter#doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain)
     */
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {

        HttpServletRequest request = (HttpServletRequest) req;
        HttpServletResponse response = (HttpServletResponse) res;

        String timerKey = "ActionContextCleanUp_doFilter: ";
        try {
            UtilTimerStack.push(timerKey);

            try {
                Integer count = (Integer)request.getAttribute(COUNTER);
                if (count == null) {
                    count = Integer.valueOf(1);
                }
                else {
                    count = Integer.valueOf(count.intValue()+1);
                }
                request.setAttribute(COUNTER, count);

                //LOG.debug("filtering counter="+count);

                chain.doFilter(request, response);
            } finally {
                int counterVal = ((Integer)request.getAttribute(COUNTER)).intValue();
                counterVal -= 1;
                request.setAttribute(COUNTER, Integer.valueOf(counterVal));
                cleanUp(request);
            }
        }
        finally {
            UtilTimerStack.pop(timerKey);
        }
    }

    /**
     * Clean up the request of threadlocals if this is the last execution
     *
     * @param req The servlet request
     */
    protected static void cleanUp(ServletRequest req) {
        // should we clean up yet?
        Integer count = (Integer) req.getAttribute(COUNTER);
        if (count != null && count > 0 ) {
            if (LOG.isDebugEnabled()) {
                LOG.debug("skipping cleanup counter="+count);
            }
            return;
        }

        // always dontClean up the thread request, even if an action hasn't been executed
        ActionContext.setContext(null);
        Dispatcher.setInstance(null);
    }

    public void destroy() {
    }

    public void init(FilterConfig arg0) throws ServletException {
    }
}